Internet-Draft ecndep February 2021
Heist Expires 24 August 2021 [Page]
Workgroup:
Transport Working Group
Internet-Draft:
draft-heist-tsvwg-ecn-deployment-observations-01
Published:
Intended Status:
Informational
Expires:
Author:
P. Heist

Explicit Congestion Notification (ECN) Deployment Observations

Abstract

This note presents data gathered at an Internet Service Provider's gateway on the observed deployment and usage of ECN. Relevant IP counter and flow tracking data was collected and analyzed for TCP and other protocols.

Status of This Memo

This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.

Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at https://datatracker.ietf.org/drafts/current/.

Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress."

This Internet-Draft will expire on 24 August 2021.

1. Introduction

To help guide the evolution of ECN, there is a need for more data on current deployment status, and observed usage of the ECN related bits, including:

  • the initiation and acceptance of ECN capable TCP flows
  • marking via CE, and feedback for TCP via the ECE and CWR flags
  • codepoints set on packets for protocols other than TCP

For several weeks, we gathered data on all traffic through an Internet Service Provider's gateway. Though some of the results are informative, we caution that a larger, more widely reviewed and geographically distributed survey would be needed to be authoritative.

2. Collection Details

From December 28, 2020 to January 20, 2021, data was gathered on all traffic into and out of the Internet gateway at FreeNet Liberec, a cooperative WISP in an urban area of the Czech Republic. A total of 122.5 TB of incoming data and 12 TB of outgoing data was seen.

Around 660 members belong to the ISP, and 861 member IP addresses on the LAN were considered active during data collection. Most member IPs are used by a household of users, while others are for individual devices and public locations.

[IPTABLES-ECN] was used to collect and analyze the data. This consists of a script to gather the data using iptables and ipsets in Linux, and an analysis program that produces textual output. An abbreviated version of the output is included in Section 5. See the referred to source repository for more details and full output.

3. Observations

Our key observations are summarized as follows, and further expanded upon in the following sections:

  • 1.44% of TCP flows initiated ECN, across 45% of member IPs.
  • The acceptance rate for ECN flows was likely >50%.
  • 24% of member IPs that negotiated TCP ECN flows saw apparent AQM marking via CE or ECE, with more congestion observed on the downstream.
  • 42% of the member IPs that saw CE or ECE were from subnets that have known AQM instances in the ISP's backhaul, and the remainder appear to be from unknown AQMs.
  • Nonzero ECN codepoints were observed on 0.053% of non-TCP packets, with possible attribution to tunneled ECN and/or misuse of the ECN field.

3.1. ECN Endpoint Activity

3.1.1. Client Initiation

Of 319.5 million TCP SYNs from LAN to WAN, 1.44% indicated ECN capability. Of 861 active member IP addresses, 390 (45.3%) attempted initiation for at least one ECN flow. A large proportion of the ECN flows are thought to come from Apple devices.

3.1.2. Server Acceptance

While 4.6 million ECN TCP SYNs were seen from LAN to WAN, 3.3 million ECN SYN-ACKs were seen in return. While it's not possible to get an exact ECN acceptance rate from this, it appears to be reasonably high, likely due to default acceptance on prevailing server operating systems like Linux, FreeBSD and recent versions of Windows Server.

3.2. RFC3168 AQM Activity

There appears to be evidence of [RFC3168] marking AQMs. Of 861 active member IP addresses:

  • 382 member IPs, or 44%, successfully negotiated any TCP ECN flows
  • 90 member IPs, or 24% of those that negotiated ECN, saw any CE or ECE marks on negotiated TCP ECN flows

Two backhaul links have fq_codel [RFC8290] deployed, serving the 10.45.64.0/24 and 10.45.235.0/24 subnets. This accounts for 38 of the 90 member IP addresses that saw CE or ECE, with the source of the remaining CE and ECE marks unknown. These are presumed to be from other [RFC3168] marking AQM instances.

Note that depending on the position of the marking AQM relative to the gateway, CE marks may not be seen on some packets, while TCP ECE flags are seen in the opposite direction. For a number of member IP addresses, we saw 0 CE marks downstream, but ECE flags set upstream, suggesting an AQM downstream from the gateway marking downstream traffic.

3.3. ECN Codepoints on Non-TCP Protocols

Referring to the packet counts in the All IP / Both Directions table in the stats output in Section 5, where M indicates megapackets and G, gigapackets:

Table 1
TCP Conntrack (X) Other Total
All 76.60 G -> 43.52 G 120.14 G
CE 10031 3.38 M 813951 4.20 M
ECT(0) 523.91 M 9.66 M 2.55 M 536.12 M
ECT(1) 63 6.68 M 182928 6.86 M

(X) UDP, ICMP, DCCP, SCTP, GRE (Conntrack All packets included in Other)

We note the following:

  • TCP accounted for 97.7% of the 536 million ECT(0) marks
  • 0.68% of all TCP packets were marked with a nonzero ECN codepoint
  • 0.053% of all non-TCP packets were marked with a nonzero ECN codepoint
  • Non-TCP accounted for 99.8% of the 4.2 million CE marks
  • Non-TCP accounted for virtually all of the ECT(1) marks

Possible explanations for ECN marks on non-TCP packets are explored further in this section.

3.3.1. Tunneled Traffic

There are several different encapsulation methods used when handling the ECN field through tunnels, as per [RFC3168] and [RFC6040]:

  1. copy the ECN field from the inner to the outer packet
  2. reset the ECN field on the outer packet to ECT(0)
  3. set Not-ECT on the outer packet

When method 3 is used at both ends of a tunnel, we would not expect to see ECN codepoint usage in either direction.

When methods 1 or 2 are used at both ends of a tunnel, we would expect to see ECT(0) on both incoming and outgoing packets. We would also expect a bias towards incoming packets, since more data is generally downloaded than uploaded, and pure ACKs do not have ECT(0) marks.

When method 3 is used at only one end of the tunnel, we would expect to see ECT(0) on packets in only one direction.

We note the following:

  • Bi-directional ECT(0) marks were observed for two member IP / port pairs, on UDP port 443 and 60001.
  • Uni-directional ECT(0) marks were observed for:

    • UDP port 4500 (IPSec NAT traversal [RFC3948]) with 23 member IP addresses downstream, and 1 member IP address upstream.
    • UDP port 51820 [WIREGUARD] with 2 member IP addresses downstream.
    • Numerous UDP ports in other ranges, mostly on the downstream.

While it's possible that some of the data observed was from tunneled ECN traffic, this can't be established definitively.

3.3.2. Use of the ECN Field for Historical Reasons

Some applications may still use historical definitions of the former TOS byte. Although RFC791 reserved the ECN field for future use, the now obsolete [RFC1349] defined the TOS field as four bits within the Type of Service octet, one of which overlaps with the ECN field. This may account for some of the observed usage of ECT(0), since the value for "minimize monetary cost" was 0001, shifted to the left one bit, coinciding with ECT(0).

3.3.3. Use of the ECN Field Inadvertently

Users of operating system's socket APIs wishing to set a DiffServ codepoint may be confused as to whether or not they need to shift the desired value left two bits before passing it in. Additionally, OS header files have been seen with out-of-date definitions for obsolete values in the former Type of Service octet, and obsolete definitions from [RFC2481].

Another possible source of confusion is the TOS field values listed in the now obsolete [RFC1349], without having been shifted. A casual reader could see the value 0001 for "minimize monetary cost" and think that they should use this value in the TOS byte, conflicting with ECT(1), not realizing that:

  • [RFC1349] is obsolete
  • even if it weren't obsolete, the TOS values must be shifted to the left by one bit

To reduce incorrect usages of the DS field, OS header files should be sanitized, obsolete RFCs more prominently marked as such, and API documentation brought up to date.

3.3.4. Use of the ECN Field Maliciously

It's possible that some software is using the ECN field to gain an advantage in Internet queues or for some other nefarious purpose. Further analysis would be needed to determine if this is the case.

4. Study Limitations and Recommendations for Future Work

4.1. ECN Acceptance Rate

While we captured the ratio of ECN SYNs to ECN SYN-ACKs, we do not have an exact count of flows that were accepted or rejected. It may be possible to do this more accurately with additional iptables rules in [IPTABLES-ECN].

4.2. Not-ECT Counts by IP

While we captured the nonzero ECN codepoints by IP address, separately for TCP and conntrack-supported protocols, we do not have a count of Not-ECT by IP address. Although it may be possible to obtain this, it would require an ipset lookup for every packet traversing the gateway.

4.3. Tunnels

Tunnel protocols are challenging because of the different encapsulation methods and protocols used. An analysis at the flow level, rather than by IP address and destination port pairs, might be more useful in identifying the usage of ECN over tunnels.

4.4. Non-TCP Protocols

More research is needed into the reasons for ECN codepoints being set on non-TCP traffic. Given the relatively low volume of this traffic, it might be practical to take packet captures of it for further analysis.

Additionally, we are currently not able to differentiate between the total number of packets for conntrack-supported and Other protocols. This could be improved with some changes to [IPTABLES-ECN].

4.5. Other Protocols

While this study looked at signals by IP address for TCP and IP/port for conntrack-supported protocols, it does not break down signals for Other protocols by IP address. Among those protocols is IPSec ESP packets, using IP protocol 50. The [IPTABLES-ECN] script could be modified to create more ipsets of type hash:ip, parallel to what was done for IP traffic as a whole, to further analyze these protocols for tunnel activity.

4.6. NS Flag

Since [RFC8311] declared that the NS (Nonce Sum) flag is again Reserved, after its now historical use by [RFC3540], we could collect any observed usages of this flag, to confirm that it's available for use in practice.

5. Abbreviated Output from ecn-stats

This abbreviated output only includes LAN to WAN flows, and a small subset of the non-TCP conntrack protocols by member IP address. For full output, see the [IPTABLES-ECN] repository.

Note the IP addresses shown here have been anonymized within the 10.0.0.0/8 address space, in a way that retains the subnet structure.

5.1. All IP

Packets, CE, ECT(0) and ECT(1) are packet counts, and use
units of M, G or T for mega, giga, or terapackets.

Total (both directions):

               TCP         Conntrack [*]   Other      Total
               ---         -------------   -----      -----
    Bytes      101.22 TB   ->              33.22 TB   134.46 TB
    Packets    76.60 G     ->              43.52 G    120.14 G
    |-CE       10031       3.38 M          813951     4.20 M
    |-ECT(0)   523.91 M    9.66 M          2.55 M     536.12 M
    |-ECT(1)   63          6.68 M          182928     6.86 M

WAN to LAN:

               TCP        Conntrack [*]   Other      Total
               ---        -------------   -----      -----
    Bytes      95.79 TB   ->              26.65 TB   122.45 TB
    Packets    41.43 G    ->              30.29 G    71.72 G
    |-CE       9298       3.38 M          721002     4.11 M
    |-ECT(0)   480.35 M   9.62 M          1.93 M     491.91 M
    |-ECT(1)   62         6.68 M          65111      6.74 M

LAN to WAN:

               TCP       Conntrack [*]   Other     Total
               ---       -------------   -----     -----
    Bytes      5.43 TB   ->              6.57 TB   12.00 TB
    Packets    35.17 G   ->              13.23 G   48.41 G
    |-CE       733       60              92949     93742
    |-ECT(0)   43.56 M   40366           614623    44.21 M
    |-ECT(1)   1         28              117817    117846

    [*] Conntrack protocols: UDP, ICMP, DCCP, SCTP, GRE
        Conntrack total Bytes and Packets included in Other

5.2. TCP initiated from LAN to WAN

IP address counts with TCP and ECN activity:

    Active (sent >= 10 SYNs):  861 (of 1195)
    Initiated any ECN flows:   390 (45.3%)
    Negotiated any ECN flows:  382 (44.4%)
    Saw CE or ECE on ECN flow: 90 (23.6% of ECN, 10.5% of all)
    Saw ECT(1) on ECN flow:    5

SYN packet count totals for active IPs:

    All SYNs:     319560652
    ECN SYNs:     4601118 (1.44% of all)
    ECN SYN/ACKs: 3273815 (71.15% of ECN SYNs)

ECN packet count totals for active IPs:

    Direction CE   ECE    ECT(0)    ECT(1)
    --------- --   ---    ------    ------
    From LAN  733  502985 42903861  1
    From WAN  9298 19367  479756419 62

ECN codepoint packet counts by active IP, for nonzero CE or ECE:

                  ECT(0)   CE   ECE    ECT(0)  CE   ECE
                  from     from from   from    from from
    IP            WAN      WAN  LAN    LAN     LAN  WAN
    --            ---      ---  ---    ---     ---  ---
    10.45.9.88    17970    0    0      0       0    431
    10.45.64.3    2909975  36   13348  245614  0    45
    10.45.64.4    228451   0    2192   60531   0    0
    10.45.64.7    1119810  28   4610   15970   0    35
    10.45.64.11   158206   0    335    52721   0    0
    10.45.64.12   466173   0    14955  28006   3    0
    10.45.64.13   287196   0    223    17277   0    0
    10.45.64.14   2264292  13   20863  362708  0    23
    10.45.64.15   46467    0    9      33894   0    0
    10.45.64.16   12238    0    1396   3339    0    0
    10.45.64.17   1058702  0    464    10578   0    0
    10.45.64.31   1137817  0    46740  114016  12   0
    10.45.64.39   519279   0    11019  44094   0    0
    10.45.64.45   229911   0    363    297811  0    0
    10.45.64.47   1257622  0    15731  410234  321  6041
    10.45.64.59   186455   0    44     71189   0    0
    10.45.64.85   4958     0    57     1069    0    0
    10.45.64.93   604641   0    16530  89847   0    0
    10.45.64.103  660575   0    10649  129808  0    0
    10.45.64.105  407561   0    2046   28347   0    0
    10.45.64.112  2007755  0    1135   58168   1    1
    10.45.64.116  427696   0    1042   30081   0    0
    10.45.64.118  275449   163  710    94141   0    170
    10.45.64.123  461008   0    3118   29852   0    0
    10.45.64.125  540511   0    52960  57523   49   0
    10.45.64.126  686366   0    12579  57480   122  0
    10.45.65.7    959608   0    176    94920   0    0
    10.45.65.16   1392760  0    4483   157057  0    0
    10.45.65.110  694373   0    1530   44914   0    0
    10.45.65.112  1140897  0    2313   171205  0    0
    10.45.65.124  73846    5    6      24228   0    9
    10.45.86.39   823913   1    13     135427  0    0
    10.45.86.41   6872888  72   3228   1116750 0    0
    10.45.87.32   62967    0    64     33255   0    0
    10.45.87.45   2052604  1    0      225774  0    0
    10.45.87.50   2500669  3    3      134178  0    0
    10.45.87.127  527732   17   22     58020   0    39
    10.45.101.96  1883157  155  156    270789  0    151
    10.45.104.24  1837837  55   63     416284  0    77
    10.45.107.73  1851297  400  416    463753  0    430
    10.45.108.24  230952   0    0      33749   0    36
    10.45.113.6   10491356 168  191    253856  0    174
    10.45.113.106 638565   34   37     173265  0    40
    10.45.114.98  1370882  1619 1792   309940  0    1739
    10.45.138.66  479880   43   56     95577   0    47
    10.45.140.73  6036     510  551    1918    0    520
    10.45.140.74  5396418  39   46     336854  0    38
    10.45.141.85  450018   39   50     157585  0    85
    10.45.145.2   118843   10   15     19309   0    25
    10.45.145.73  3484464  1    0      153147  0    0
    10.45.153.10  714256   6    11     80712   0    0
    10.45.154.82  2355299  22   25     263636  0    44
    10.45.155.68  1849086  1    1      349722  0    0
    10.45.155.71  9089268  144  143    660457  1    152
    10.45.158.197 17618743 493  53     369921  0    0
    10.45.158.198 1019414  13   13     222440  0    25
    10.45.176.114 736022   32   46     88713   0    62
    10.45.176.119 2393601  38   47     167329  0    68
    10.45.177.68  17191899 22   24     201187  0    27
    10.45.182.75  615134   6    7      100995  0    13
    10.45.183.117 199726   131  145    52876   6    152
    10.45.183.204 2729641  8    10     851838  0    0
    10.45.212.82  2497321  18   23     213484  0    48
    10.45.229.81  1043941  268  2104   36517   1    0
    10.45.230.25  4560825  3132 18481  290819  0    0
    10.45.230.204 28514121 1    1      321299  0    0
    10.45.231.31  62246    16   9      12782   0    30
    10.45.234.197 265034   188  225    98664   0    153
    10.45.235.6   140242   0    217    42778   0    0
    10.45.235.24  213822   0    388    50485   0    0
    10.45.235.59  1017759  16   897    121453  0    30
    10.45.235.89  8066090  56   31899  637830  176  5630
    10.45.235.90  3878916  727  4278   460048  0    709
    10.45.235.92  15410232 151  169965 1030037 41   1784
    10.45.235.94  344002   0    1394   3913608 0    0
    10.45.235.196 2234     0    157    1323    0    0
    10.45.235.199 2166     0    56     676     0    0
    10.45.235.200 5279     0    220    2311    0    0
    10.45.235.203 2966     0    234    1765    0    0
    10.45.235.206 154701   0    3484   333     0    0
    10.45.235.208 5076     0    378    3240    0    0
    10.45.238.75  4916805  196  262    942367  0    229
    10.45.241.101 2838055  0    740    303980  0    0
    10.45.242.72  81526    5    5      36884   0    11
    10.45.242.146 894737   21   25     85268   0    44
    10.45.243.69  1946622  2    3      64838   0    0
    10.45.249.6   621444   0    2461   75061   0    0
    10.45.249.34  180747   0    2260   128409  0    0
    10.45.251.37  455964   39   171    18996   0    0
    10.45.251.114 14208298 134  13794  946610  0    0

5.3. Non-TCP conntrack-supported protocols initiated from LAN to WAN

Protocols included:

    UDP, ICMP, DCCP, SCTP, GRE

Active IPs:

    Active IPs with ECN signals:              420
    Active IP/dstport pairs with ECN signals: 24972

ECN packet count totals for active IPs:

    Direction CE      ECT(0)  ECT(1)
    --------- --      ------  ------
    From LAN  59      26692   28
    From WAN  2838929 9562002 6632561

ECN codepoint packet counts by client IP, with selected ports:
    (ports with '*' had >100 ECT(0) marks)

                           ECT(0)  CE      ECT(1)  ECT(0) CE   ECT(1)
                           from    from    from    from   from from
    IP/Port                WAN     WAN     WAN     LAN    LAN  LAN
    -------                ---     ---     ---     ---    ---  ---
    10.45.10.0             0       0       0       201    0    0
    10.45.10.4             0       0       0       14     0    0
    10.45.10.5             0       0       0       20     0    0
    10.45.10.6             0       0       0       9      0    0
    10.45.10.7             0       0       0       8      0    0
    10.45.10.8             0       0       0       39     0    0
    10.45.10.11            0       0       0       8      0    0
    10.45.10.12            0       0       0       2      0    0
    10.45.10.42            0       0       0       6      0    0
    10.45.10.61            0       0       0       2      0    0
    10.45.10.70            0       0       0       44     0    0
    10.45.10.71            0       0       0       5      0    0
    10.45.10.73            0       0       0       7      0    0
    10.45.10.77            0       0       0       13     0    0
    10.45.10.81            0       0       0       10     0    0
    10.45.10.82            0       0       0       8      0    0
    10.45.10.83            0       0       0       3      0    0
    10.45.10.95            0       0       0       59     0    0
    10.45.10.96            0       0       0       39     0    0
    10.45.10.129           0       403     1       0      0    0
    10.45.10.196           0       0       0       80     0    0
    10.45.10.197           0       0       0       63     0    0
    10.45.10.201           0       0       0       3      0    0
    10.45.10.204           0       0       0       25     0    0
    10.45.10.227           0       0       0       40     0    0
    10.45.10.228           0       0       0       7      0    0
    10.45.10.244           0       0       0       14     0    0
    10.45.10.245           0       0       0       7      0    0
    10.45.64.3             0       0       0       100    0    0
    10.45.64.4             0       0       0       31     0    0
    10.45.64.6             0       0       0       2      0    0
    10.45.64.7             12      126     20      8      0    0
    10.45.64.10            0       0       0       29     0    0
    10.45.64.11            0       0       0       67     0    0
    10.45.64.12            0       0       0       6      0    0
    10.45.64.13            0       0       0       35     0    0
    10.45.64.14            0       0       0       121    0    0
    10.45.64.15            0       0       0       52     0    0
    10.45.64.16            0       0       0       18     0    0
    10.45.64.19            16      0       0       0      0    0
      udp:4500 (ipsec-na.. 11      0       0       0      0    0
    10.45.64.31            34129   2468    58304   27     0    0
      udp:37658            0       0       4346    0      0    0
    * udp:38129            24957   2468    15281   0      0    0
      udp:38884            0       0       10409   0      0    0
    * udp:40871            288     0       2269    0      0    0
    * udp:41621            3057    0       14609   0      0    0
    * udp:41744            171     0       61      0      0    0
      udp:43588            0       0       6746    0      0    0
      udp:45444            0       0       1292    0      0    0
    * udp:45465            866     0       0       0      0    0
      udp:45483            0       0       1838    0      0    0
    * udp:45522            4764    0       708     0      0    0
    10.45.64.39            0       0       0       75     0    0
    10.45.64.45            0       0       0       50     0    0
    10.45.64.47            0       0       0       11     0    0
    10.45.64.51            0       0       0       2      0    0
    10.45.64.59            56      1624    10      593    0    0
      udp:3478 (stun)      56      1624    10      0      0    0
    10.45.64.85            0       0       0       4      0    0
    10.45.64.86            7       434404  3       9      0    0
      udp:4400 (ds-srv)    0       29065   0       0      0    0
      udp:14757            0       97175   0       0      0    0
      udp:24173            0       35437   0       0      0    0
      udp:29493            0       120959  0       0      0    0
      udp:44495            0       41547   0       0      0    0
      udp:53678            0       109978  0       0      0    0
    10.45.64.89            7       50      0       4      0    0
    10.45.64.93            598     2971    341     75     0    0
    * udp:3478 (stun)      598     2971    341     0      0    0
    10.45.64.98            0       0       32780   0      0    0
      udp:6008             0       0       9234    0      0    0
      udp:7008 (afs3-upd.. 0       0       23546   0      0    0
    10.45.64.99            132     2094    73      0      0    0
      udp:3478 (stun)      0       3       0       0      0    0
    10.45.64.103           0       0       0       47     0    0
    10.45.64.104           70      293     31      1      0    0
    10.45.64.105           213     33440   0       7      0    0
    * udp:443 (https)      213     33440   0       0      0    0
    10.45.64.107           0       0       0       2      0    0
    10.45.64.108           0       0       0       1      0    0
    10.45.64.111           1       1       0       0      0    0
    10.45.64.112           0       421     0       48     0    0
    10.45.64.116           4       143     8       64     0    8
    10.45.64.118           0       0       0       77     0    0
    10.45.64.121           0       2107    0       0      0    0
      udp:38603            0       2100    0       0      0    0
    10.45.64.123           0       0       0       13     0    0
    10.45.64.124           6       0       0       0      0    0
      udp:443 (https)      6       0       0       0      0    0
    10.45.64.125           0       0       0       22     0    0
    10.45.64.126           1       10      0       37     0    0
    10.45.65.0             0       0       0       42     0    0
    10.45.65.1             0       0       0       45     0    0
    10.45.65.5             0       0       0       17     0    0
    10.45.65.7             0       0       0       30     0    0
    10.45.65.11            0       0       0       6      0    0
    10.45.65.16            1686    40141   36888   505    0    0
    * udp:3478 (stun)      1595    22049   4       0      0    0
      udp:26808            0       0       36805   0      0    0
      udp:62348            0       15738   0       0      0    0
    10.45.65.17            0       4       0       0      0    0
    10.45.65.66            0       17      0       94     0    0
      udp:3478 (stun)      0       17      0       0      0    0
    10.45.65.94            319     0       1       25     0    0
      udp:3478 (stun)      0       0       1       0      0    0
    10.45.65.95            0       0       0       8      0    0
    10.45.65.104           0       0       0       41     0    0
    10.45.65.107           12      77      2       5      0    0
    10.45.65.110           0       0       0       38     0    0
    10.45.65.112           39      1168    18      75     0    0
    10.45.65.122           2       5       0       0      0    0
    10.45.65.123           0       0       0       1      0    0
    10.45.65.124           0       0       0       11     0    0
    10.45.65.127           0       0       0       5      0    0
    10.45.75.90            0       0       0       1      0    0
    10.45.80.28            2       8       1       0      0    0
    10.45.80.79            4       7       0       2      0    0
    10.45.80.85            0       0       0       10     0    0
    10.45.80.99            0       0       0       11     0    0
    10.45.83.76            0       0       0       3      0    0
    10.45.83.80            28      51      11      0      0    0
    10.45.85.127           301     174     30747   68     0    0
    * udp:599 (acp)        222     174     45      0      0    0
      udp:6008             0       0       30702   0      0    0
    * udp:60001            49      0       0       65     0    0
    10.45.86.16            13      0       0       2      0    0
      udp:4500 (ipsec-na.. 8       0       0       0      0    0
      udp:51820 (wiregua.. 5       0       0       0      0    0
    10.45.86.36            0       0       0       4      0    0
    10.45.86.39            205     37619   107     50     0    0
      udp:29492            0       2512    0       0      0    0
      udp:64733            0       30711   0       0      0    0
    10.45.86.40            2       0       0       0      0    0
      udp:443 (https)      2       0       0       0      0    0
    10.45.86.43            0       11      0       532    0    0
    10.45.86.68            760     3528    614     325    0    0
      udp:80 (http)        0       2       0       0      0    0
    10.45.87.32            12      0       0       14     0    0
    10.45.87.44            709     4963    623     0      0    0
      udp:80 (http)        0       1       0       0      0    0
      udp:6881             3       1313    43      0      0    0
    10.45.87.45            0       0       0       185    0    0
    10.45.87.48            0       0       0       82     0    0
    10.45.87.50            3       0       9       68     0    0
      udp:4500 (ipsec-na.. 3       0       9       0      0    0
    10.45.87.103           0       0       0       2      0    0
    10.45.87.112           0       1       0       0      0    0
    10.45.87.113           0       0       0       33     0    0
    10.45.87.127           0       0       0       44     0    0
    10.45.92.74            31      0       1       2      0    0
    10.45.93.69            15      122     6       0      0    0
    10.45.93.75            361     2945    278     4      0    0
    10.45.93.79            0       0       0       8      0    0
    10.45.98.71            2       8       0       0      0    0
    10.45.98.72            0       1       0       40     0    0
      udp:3478 (stun)      0       1       0       0      0    0
    10.45.101.96           0       0       0       140    0    0
    10.45.101.100          0       0       0       12     0    0
    10.45.101.101          2       10      7       0      0    0
    10.45.101.103          21      21899   15      0      0    0
      udp:58479            0       21372   0       0      0    0
    10.45.101.104          0       0       10      33     0    0
    10.45.104.24           0       0       0       324    0    0
    10.45.104.104          16      72      2       60     0    0
    10.45.107.73           32      0       1       58     0    0
      udp:4500 (ipsec-na.. 32      0       1       0      0    0
    10.45.107.79           34      0       0       70     0    0
      udp:443 (https)      34      0       0       0      0    0
    10.45.107.81           0       4421    0       3      0    0
      udp:61094            0       4421    0       0      0    0
    10.45.108.3            0       0       0       1      0    0
    10.45.108.4            33      5079    90      1      0    0
      udp:33027            0       2978    0       0      0    0
    10.45.108.13           0       0       0       14     0    0
    10.45.108.24           799     5543    1059    117    0    0
    * udp:40211            107     0       0       0      0    0
    10.45.108.25           1       2       1       799    0    0
    10.45.108.66           0       0       0       0      0    1
    10.45.108.69           0       0       0       2      0    0
    10.45.108.71           28      12830   0       0      0    0
      udp:34665            0       12462   0       0      0    0
    10.45.108.75           0       0       6395176 38     0    0
      udp:6008             0       0       1755476 0      0    0
      udp:7008 (afs3-upd.. 0       0       1827173 0      0    0
      udp:8008 (http-alt)  0       0       740987  0      0    0
      udp:9008             0       0       809024  0      0    0
      udp:10008 (octopus)  0       0       380001  0      0    0
      udp:11008            0       0       578400  0      0    0
      udp:12008 (accurac.. 0       0       231619  0      0    0
      udp:13008            0       0       72496   0      0    0
    10.45.108.76           0       0       0       2      0    0
    10.45.108.77           0       0       0       31     0    0
    10.45.108.80           337     1566    173     10     0    0
    10.45.108.95           1       5       0       283    0    0
    10.45.108.126          0       0       0       12     0    0
    10.45.112.74           9       95      4       371    0    0
    10.45.112.102          0       0       0       29     0    0
    10.45.112.139          0       0       0       5      0    0
    10.45.112.154          0       0       0       4      0    0
    10.45.112.165          0       0       0       24     0    0
    10.45.112.172          6333    0       0       0      0    0
    * udp:443 (https)      6333    0       0       0      0    0
    10.45.112.216          0       0       0       2      0    0
    10.45.113.6            147184  0       0       136    0    0
    * udp:4500 (ipsec-na.. 147184  0       0       0      0    0
    10.45.113.7            453     0       10      52     0    0
    * udp:443 (https)      309     0       0       0      0    0
    * udp:4500 (ipsec-na.. 144     0       10      0      0    0
    10.45.113.9            0       0       0       60     0    0
    10.45.113.11           0       0       0       187    0    0
    10.45.113.27           0       0       0       1      0    0
    10.45.113.30           0       0       0       4      0    0
    10.45.113.33           0       0       0       2      0    0
    10.45.113.34           0       0       0       58     0    0
    10.45.113.35           0       0       0       6      0    0
    10.45.113.36           0       0       0       2      0    0
    10.45.113.66           1       11      0       0      0    0
    10.45.113.90           0       0       0       163    0    0
    10.45.113.94           17      62      2       0      0    0
    10.45.113.97           0       0       0       19     0    0
    10.45.113.99           11      76      12      15     0    0
    10.45.113.104          818     0       0       0      0    0
    * udp:4500 (ipsec-na.. 818     0       0       0      0    0
    10.45.113.106          0       0       0       10     0    0
    10.45.113.119          0       178     0       313    0    0
      udp:3478 (stun)      0       178     0       0      0    0
    10.45.113.122          36      0       0       0      0    0
      udp:4500 (ipsec-na.. 36      0       0       0      0    0
    10.45.113.124          0       0       0       201    0    0
    10.45.114.8            0       3       0       0      0    0
    10.45.114.10           0       0       0       3      0    0
    10.45.114.42           286     12      67      3      0    0
    * udp:51820 (wiregua.. 286     0       66      0      0    0
    10.45.114.98           0       0       0       10     0    0
    10.45.120.25           0       0       0       53     0    0
    10.45.120.34           0       0       0       12     0    0
    10.45.120.78           0       0       0       715    0    0
    10.45.122.51           686     28190   122     66     0    0
      udp:45622            0       5782    0       0      0    0
      udp:59437            0       17791   0       0      0    0
    10.45.124.31           1720    5946    16897   105    0    0
      udp:3478 (stun)      0       6       0       0      0    0
    * udp:50451            1720    0       15875   0      0    0
      udp:50919            0       2428    0       0      0    0
      udp:50996            0       0       1016    0      0    0
      udp:57403            0       1944    0       0      0    0
    10.45.124.43           0       0       0       12     0    0
    10.45.124.73           37      0       0       0      0    0
      udp:4500 (ipsec-na.. 37      0       0       0      0    0
    10.45.124.74           0       0       0       1      0    0
    10.45.124.89           0       0       0       2      0    0
    10.45.124.107          142     626895  83      0      0    0
      udp:24616            0       501142  0       0      0    0
      udp:51123            0       124060  0       0      0    0
    10.45.124.111          0       1538    166     0      0    0
      udp:4748             0       1491    166     0      0    0
    10.45.124.117          0       0       0       248    0    0
    10.45.125.97           0       0       0       2      0    0
    10.45.125.99           130     6235    29      1      0    0
      udp:8609 (canon-cp.. 0       3002    0       0      0    0
    10.45.125.104          0       0       0       3      0    0
    10.45.125.105          0       0       0       7      0    0
    10.45.136.82           0       0       0       1      0    0
    10.45.136.198          0       0       0       8      0    0
    10.45.136.199          68      3210    7       0      0    0
      udp:22312            0       2452    0       0      0    0
    10.45.136.200          0       44      1       0      0    0
    10.45.137.4            4603    0       0       1882   0    0
    * udp:443 (https)      4603    0       0       1882   0    0
    10.45.137.21           0       0       0       118    0    0
    10.45.137.27           4       0       0       63     0    0
    10.45.137.29           0       0       0       0      0    1
    10.45.137.46           9       154     0       6      0    0
      udp:443 (https)      9       0       0       0      0    0
    10.45.137.53           0       0       0       7      0    0
    10.45.137.55           0       0       1       37     0    0
    10.45.137.62           5       29      1       14     0    0
      udp:443 (https)      2       0       0       0      0    0
    10.45.137.119          16      203825  12      4      0    0
      udp:16772            0       55846   0       0      0    0
      udp:25135            0       24694   0       0      0    0
      udp:25476            0       66965   0       0      0    0
      udp:51123            0       54265   0       0      0    0
      udp:55430            0       1138    0       0      0    0
    10.45.137.123          2       4190    1       1      0    0
      udp:29363            0       3283    0       0      0    0
    10.45.138.52           3093    18938   0       0      0    0
    * udp:42420            3087    18871   0       0      0    0
    10.45.138.66           0       0       0       249    0    0
    10.45.138.88           43      107     10      0      0    0
    10.45.138.95           0       0       0       20     0    0
    10.45.140.0            0       0       0       84     0    0
    10.45.140.5            0       0       0       2      0    0
    10.45.140.28           0       0       0       1      0    0
    10.45.140.74           0       0       0       12     0    0
    10.45.140.81           0       0       0       26     0    0
    10.45.140.100          143     465     37      0      0    0
    10.45.140.103          0       0       0       16     0    0
    10.45.140.104          0       0       0       4      0    0
    10.45.140.109          0       0       0       2      0    0
    10.45.140.118          0       0       0       27     0    0
    10.45.140.121          0       7032    0       17     0    0
      udp:49710            0       1160    0       0      0    0
      udp:53984            0       2694    0       0      0    0
      udp:58704            0       1597    0       0      0    0
    10.45.140.122          0       3       0       0      0    0
    10.45.140.123          0       0       4       0      0    0
    10.45.140.127          0       0       0       15     0    0
    10.45.140.133          0       0       0       0      1    0
    10.45.140.169          0       0       0       59     0    0
    10.45.140.171          0       0       0       14     0    0
    10.45.141.2            91      0       0       12     0    0
      udp:443 (https)      91      0       0       0      0    0
    10.45.141.6            0       0       0       24     0    0
    10.45.141.14           0       0       0       2      0    0
    10.45.141.17           2       37      1       17     0    0
    10.45.141.19           0       0       0       2      0    0
    10.45.141.82           579     0       0       21     0    0
    * udp:443 (https)      579     0       0       0      0    0
    10.45.141.83           0       0       0       14     0    0
    10.45.141.84           0       0       0       90     0    0
    10.45.141.85           0       0       0       518    0    0
    10.45.141.86           0       0       0       6      0    0
    10.45.141.87           0       0       0       2      0    0
    10.45.141.103          0       0       0       57     0    0
    10.45.141.106          7       190     3947    1079   0    0
      udp:3478 (stun)      0       24      12      0      0    0
    * udp:5001 (commplex.. 0       0       0       1072   0    0
      udp:40208            0       0       3932    0      0    0
    10.45.141.125          0       0       0       2      0    0
    10.45.144.20           2       6       2       1      0    0
    10.45.144.43           0       0       0       3      0    0
    10.45.144.55           0       0       0       2      0    0
    10.45.144.68           0       0       0       363    0    0
    10.45.144.73           0       0       0       14     0    0
    10.45.144.75           0       0       3       51     0    0
    10.45.144.77           51      289     35      24     0    0
    10.45.144.105          413     0       11      1      0    0
    * udp:4500 (ipsec-na.. 413     0       11      0      0    0
    10.45.144.139          1496    0       0       0      0    0
    * udp:443 (https)      1496    0       0       0      0    0
    10.45.144.197          0       0       0       102    0    0
    10.45.145.2            0       0       0       15     0    0
    10.45.145.26           0       0       0       44     0    0
    10.45.145.39           2503039 0       0       11     0    0
      udp:443 (https)      4       0       0       0      0    0
    * udp:4500 (ipsec-na.. 2503035 0       0       0      0    0
    10.45.145.56           0       0       0       3      0    0
    10.45.145.72           0       0       0       32     0    0
    10.45.145.75           3024    0       0       0      0    0
    * udp:443 (https)      3024    0       0       0      0    0
    10.45.145.81           8691    107114  8245    292    0    0
      udp:80 (http)        0       2       0       0      0    0
    * udp:6881             355     8092    672     0      0    0
      udp:19517            0       1097    0       0      0    0
      udp:22784            0       3441    0       0      0    0
    * udp:25223            110     0       0       0      0    0
    * udp:37526            139     0       0       0      0    0
    * udp:40631            191     0       0       0      0    0
      udp:40990            0       33415   0       0      0    0
      udp:51820 (wiregua.. 0       3       0       0      0    0
    10.45.145.96           0       0       0       7      0    0
    10.45.145.98           0       0       0       3      0    0
    10.45.145.107          0       9       0       0      0    0
    10.45.145.109          0       0       0       9      35   0
    10.45.145.115          0       0       0       11     0    0
    10.45.146.66           52      88      7       26     0    0
    10.45.146.195          0       0       0       2      0    0
    10.45.146.200          1471    0       0       49     0    0
    * udp:4500 (ipsec-na.. 1471    0       0       0      0    0
    10.45.146.201          0       0       0       9      0    0
    10.45.153.10           0       0       0       33     0    0
    10.45.153.194          2       86      2       0      0    0
    10.45.154.6            0       0       0       9      0    0
    10.45.154.81           0       0       0       4      0    0
    10.45.154.82           0       0       0       140    0    0
    10.45.154.100          0       0       0       14     0    0
    10.45.154.105          0       0       0       17     0    0
    10.45.154.112          0       0       0       5      0    0
    10.45.154.113          1       88      2       3      0    0
    10.45.154.115          0       0       0       224    0    0
    10.45.155.12           0       0       0       11     0    0
    10.45.155.67           0       0       0       1      0    0
    10.45.155.68           0       0       0       237    0    0
    10.45.155.69           0       0       0       1      0    0
    10.45.155.71           0       0       0       246    0    0
    10.45.155.73           0       0       0       72     0    0
    10.45.155.74           0       1       0       0      0    0
      udp:3478 (stun)      0       1       0       0      0    0
    10.45.155.75           0       4       0       0      0    0
    10.45.155.76           0       1       0       0      0    0
    10.45.155.217          0       0       0       15     0    0
    10.45.155.229          4       42      6       48     0    0
    10.45.156.94           25      152     8       0      0    0
    10.45.156.105          0       5362    0       19     0    0
      udp:58796            0       5362    0       0      0    0
    10.45.156.127          0       0       0       22     0    0
    10.45.158.115          0       0       0       402    0    0
    10.45.158.124          0       0       0       4      0    0
    10.45.158.127          0       0       0       3      0    0
    10.45.158.195          0       1630    3       25     0    0
      udp:6881             0       1610    0       0      0    0
    10.45.158.197          0       0       0       82     0    0
    10.45.158.198          0       0       0       204    0    0
    10.45.158.204          0       0       0       118    0    0
    10.45.158.206          9       32      2       0      0    0
    10.45.176.114          0       0       0       68     0    0
    10.45.176.116          188     1702    191     1      0    0
    10.45.176.117          0       0       0       35     0    0
    10.45.176.119          9320    1028270 11302   218    0    0
      udp:6881             0       91498   83      0      0    0
    * udp:6900             322     0       0       0      0    0
      udp:8999 (bctp)      0       405853  3       0      0    0
    * udp:10556            741     0       0       0      0    0
      udp:11778            0       311705  0       0      0    0
    * udp:12111            274     0       0       0      0    0
      udp:21606            0       5678    0       0      0    0
      udp:23578            0       4281    0       0      0    0
      udp:24488            0       2140    0       0      0    0
      udp:35849            0       2632    0       0      0    0
    * udp:37758            212     721     0       0      0    0
      udp:40954            0       27113   0       0      0    0
    * udp:42012            380     26      101     0      0    0
      udp:48235            0       3182    0       0      0    0
    * udp:50321            2066    14226   5982    0      0    0
    * udp:50838            389     0       0       0      0    0
      udp:50884            0       0       2743    0      0    0
      udp:51413            39      1712    0       0      0    0
      udp:54457            0       3504    0       0      0    0
      udp:56769            0       23761   0       0      0    0
      udp:59025            0       3034    0       0      0    0
    * udp:60050            3000    3961    1478    0      0    0
      udp:60062            0       13672   0       0      0    0
      udp:64329            0       75590   0       0      0    0
    10.45.176.120          0       0       0       73     21   18
    10.45.176.206          37      689     3       34     0    0
      udp:3478 (stun)      37      685     3       0      0    0
    10.45.176.207          8       143     0       5      0    0
    10.45.176.209          12      88      1       11     0    0
    10.45.176.210          10      32      4       1      0    0
    10.45.176.214          25      8900    0       18     0    0
      udp:6672 (vision-s.. 23      8900    0       0      0    0
    10.45.176.224          1       0       0       114    0    0
    10.45.176.225          120     786     137     1      0    0
    10.45.176.226          0       0       0       4      0    0
    10.45.176.237          4       0       0       0      0    0
      udp:443 (https)      4       0       0       0      0    0
    10.45.177.66           9       213     8349    0      0    0
      udp:6672 (vision-s.. 0       0       8334    0      0    0
    10.45.177.68           12      64      8       124    0    0
    10.45.177.75           0       2       0       66     0    0
    10.45.177.197          0       2       1       0      0    0
    10.45.182.75           44      71      17      25     0    0
    10.45.182.85           41      2612    5024    0      0    0
      udp:45864            0       0       4985    0      0    0
    10.45.182.136          0       0       0       8      0    0
    10.45.183.117          0       0       0       15     0    0
    10.45.183.199          45      1579    0       8      0    0
      udp:3478 (stun)      45      1578    0       0      0    0
    10.45.183.204          0       9478    0       731    0    0
    * udp:4500 (ipsec-na.. 0       0       0       237    0    0
      udp:22885            0       9404    0       0      0    0
    10.45.183.205          0       0       1       3      0    0
      udp:4500 (ipsec-na.. 0       0       1       0      0    0
    10.45.183.209          3       1       0       280    0    0
    10.45.183.219          0       0       0       61     0    0
    10.45.203.6            0       0       0       2      0    0
    10.45.212.17           10472   25127   16430   0      0    0
    * udp:62503            10452   23528   16423   0      0    0
    10.45.212.27           0       0       0       1      0    0
    10.45.212.29           0       0       0       30     0    0
    10.45.212.51           0       0       0       2      0    0
    10.45.212.82           0       1       1       28     0    0
    10.45.212.84           0       0       0       2      0    0
    10.45.212.199          0       0       0       1      0    0
    10.45.212.202          0       0       0       4      0    0
    10.45.212.205          0       0       0       299    0    0
    10.45.212.207          0       0       0       85     0    0
    10.45.229.75           3       0       0       0      0    0
      udp:443 (https)      3       0       0       0      0    0
    10.45.229.78           6694314 0       0       113    0    0
    * udp:4500 (ipsec-na.. 6694314 0       0       0      0    0
    10.45.229.79           0       0       0       27     0    0
    10.45.229.81           0       0       0       3      0    0
    10.45.229.101          0       0       0       69     0    0
    10.45.229.104          128     525     128     0      0    0
    10.45.229.119          0       0       0       20     0    0
    10.45.230.20           0       0       0       1      0    0
    10.45.230.25           10      0       72      32     0    0
      udp:4500 (ipsec-na.. 10      0       72      0      0    0
    10.45.230.89           495     3537    296     4      0    0
    10.45.230.99           7       0       5       2      0    0
      udp:4500 (ipsec-na.. 7       0       5       0      0    0
    10.45.230.204          9       57      18      110    0    0
    10.45.230.207          18      33      1       1      0    0
    10.45.230.212          0       0       0       2      0    0
    10.45.230.223          0       0       0       3      0    0
    10.45.230.224          27927   93      13      0      0    0
    * udp:50323            322     0       0       0      0    0
    * udp:50361            128     0       0       0      0    0
    * udp:52065            409     0       0       0      0    0
    * udp:55236            257     0       0       0      0    0
    * udp:57072            142     0       0       0      0    0
    * udp:58494            170     0       0       0      0    0
    * udp:59465            160     0       0       0      0    0
    * udp:59659            445     0       0       0      0    0
    * udp:60874            129     0       0       0      0    0
    * udp:60898            102     0       0       0      0    0
    * udp:61122            302     0       0       0      0    0
    * udp:61312            137     0       0       0      0    0
    * udp:61669            124     0       0       0      0    0
    * udp:62889            24738   0       0       0      0    0
    * udp:63354            122     0       0       0      0    0
    * udp:63474            107     0       0       0      0    0
    10.45.230.226          0       0       0       3      0    0
    10.45.230.228          0       45      0       0      1    0
    10.45.230.229          682     21      3       0      0    0
    * udp:4500 (ipsec-na.. 682     0       0       0      0    0
    10.45.231.16           433     0       0       24     0    0
    * udp:4500 (ipsec-na.. 433     0       0       0      0    0
    10.45.231.21           40      256     81      0      0    0
    10.45.231.31           0       0       0       32     0    0
    10.45.231.53           2       46      0       0      0    0
    10.45.231.61           4151    0       1       13     0    0
    * udp:4500 (ipsec-na.. 4151    0       1       0      0    0
    10.45.231.80           0       0       0       6      0    0
    10.45.231.99           0       0       0       40     0    0
    10.45.231.102          0       0       0       11     0    0
    10.45.231.114          0       0       0       47     0    0
    10.45.233.16           0       0       0       55     0    0
    10.45.233.39           1       13      2       1      0    0
    10.45.233.41           0       0       3       4      0    0
    10.45.233.42           0       0       0       115    0    0
    10.45.233.47           0       0       0       1      0    0
    10.45.233.55           0       0       0       3      0    0
    10.45.234.197          320     0       11      2      0    0
    * udp:4500 (ipsec-na.. 320     0       11      0      0    0
    10.45.235.6            107     454     62      6      0    0
    10.45.235.11           250     0       0       0      0    0
    * udp:443 (https)      249     0       0       0      0    0
    10.45.235.13           0       0       0       4      0    0
    10.45.235.16           24      56      3       0      0    0
    10.45.235.19           0       0       0       3      0    0
    10.45.235.24           0       2       0       33     0    0
    10.45.235.25           2310    28152   68      17     0    0
    * udp:443 (https)      2214    0       0       0      0    0
      udp:6881             0       13339   0       0      0    0
      udp:31708            0       4595    0       0      0    0
      udp:51413            0       5367    0       0      0    0
      udp:52372            0       3975    0       0      0    0
    10.45.235.49           672     3165    14      0      0    0
    * udp:443 (https)      672     79      0       0      0    0
      udp:59418            0       3078    0       0      0    0
    10.45.235.52           23      0       0       0      0    0
      udp:4500 (ipsec-na.. 23      0       0       0      0    0
    10.45.235.59           0       0       0       58     0    0
    10.45.235.66           0       0       0       4      0    0
    10.45.235.89           165     2580    23      582    0    0
    * udp:3478 (stun)      165     2580    23      0      0    0
    10.45.235.90           0       0       0       332    0    0
    10.45.235.92           0       0       0       1007   0    0
    10.45.235.93           229     3272    306     13     0    0
    10.45.235.94           0       0       0       10     0    0
    10.45.238.75           0       0       0       1744   0    0
    10.45.238.104          0       2576    0       7      0    0
      udp:443 (https)      0       2576    0       0      0    0
    10.45.239.66           40      0       5       0      0    0
      udp:4500 (ipsec-na.. 40      0       5       0      0    0
    10.45.239.219          1       0       0       18     0    0
      udp:443 (https)      1       0       0       0      0    0
    10.45.240.86           0       0       0       5      0    0
    10.45.241.57           216     66079   437     0      0    0
      udp:4500 (ipsec-na.. 0       0       21      0      0    0
      udp:33522            0       37844   0       0      0    0
      udp:37859            0       27536   0       0      0    0
    10.45.241.94           0       0       0       44     0    0
    10.45.241.98           0       0       0       4      0    0
    10.45.241.101          68946   10      2       120    0    0
    * udp:4500 (ipsec-na.. 68942   0       0       0      0    0
    10.45.241.121          0       0       0       2      0    0
    10.45.242.72           0       0       0       4      0    0
    10.45.242.81           0       0       0       14     1    0
    10.45.242.144          0       0       0       5      0    0
    10.45.242.146          0       0       0       30     0    0
    10.45.242.161          143     134     2297    139    0    0
    * udp:4500 (ipsec-na.. 115     0       4       0      0    0
      udp:27032            0       78      2293    0      0    0
    10.45.243.13           13877   63      1       0      0    0
    * udp:20911            13853   0       0       0      0    0
    10.45.243.41           12      0       0       14     0    0
      udp:443 (https)      12      0       0       0      0    0
    10.45.243.69           0       0       0       66     0    0
    10.45.243.71           0       28      0       2      0    0
      udp:80 (http)        0       28      0       0      0    0
    10.45.243.109          0       2008    0       7      0    0
      udp:41697            0       2002    0       0      0    0
    10.45.248.33           2       8       0       10     0    0
      udp:3478 (stun)      2       8       0       0      0    0
    10.45.248.94           0       0       0       11     0    0
    10.45.248.118          0       0       0       2      0    0
    10.45.249.6            0       0       0       1502   0    0
    10.45.249.34           25      0       0       154    0    0
      udp:443 (https)      25      0       0       0      0    0
    10.45.249.99           68      558     88      0      0    0
    10.45.249.104          0       0       0       7      0    0
      udp:4500 (ipsec-na.. 0       0       0       6      0    0
    10.45.250.89           0       0       0       5      0    0
    10.45.251.37           0       0       0       19     0    0
    10.45.251.110          9       72      1       0      0    0
    10.45.251.119          0       0       0       23     0    0
    10.45.253.59           0       0       0       1      0    0
      udp:4500 (ipsec-na.. 0       0       0       1      0    0
    10.45.253.61           0       0       0       53     0    0
    10.45.253.84           121     0       0       16     0    0
    * udp:443 (https)      121     0       0       0      0    0
    10.45.253.93           0       0       0       4      0    0
    10.45.253.100          0       0       0       142    0    0
    10.45.253.121          0       0       0       2      0    0
    10.45.254.94           0       0       0       12     0    0
    10.45.255.90           1       125     0       0      0    0
    10.45.255.97           0       0       0       36     0    0

ECN codepoint packet counts for selected ports:

                           ECT(0)  CE      ECT(1)  ECT(0) CE   ECT(1)
                           from    from    from    from   from from
    Port                   WAN     WAN     WAN     LAN    LAN  LAN
    ----                   ---     ---     ---     ---    ---  ---
    icmp:network-unreach.. 321     4       0       0      0    0
    icmp:host-unreachable  1171    2575    43      22990  0    0
    icmp:port-unreachable  6632    40795   3539    404    0    0
    icmp:ttl-zero-during.. 65      2       66      0      0    0
    ipencap:0              0       0       0       1      0    0
    udp:53 (domain)        0       403     1       0      0    0
    udp:80 (http)          0       33      0       0      0    0
    udp:443 (https)        20006   36095   0       1882   0    0
    udp:599 (acp)          238     261     59      0      0    0
    udp:1024-3457 [81]     100     618     9       34     59   28
    udp:3478 (stun)        2498    31725   394     0      0    0
    udp:3553-4492 [19]     1       29449   0       0      0    0
    udp:4500 (ipsec-nat-t) 9422229 0       151     244    0    0
    udp:4548-51819 [8177]  62692   2291117 6604184 1072   0    0
    udp:51820 (wireguard)  291     3       66      0      0    0
    udp:51821-65535 [9371] 45758   405849  24049   65     0    0

6. IANA Considerations

This document has no IANA actions.

7. Security Considerations

There are no known security considerations introduced by this note.

8. Affiliation

The author wrote the script used to deploy fq_codel to the two backhaul subnets mentioned in Section 3.2.

9. Acknowledgements

Thanks go to:

  • Adam Pribyl, for gathering data at the FreeNet gateway
  • Jonathan Morton and Rodney Grimes, for helping to analyze the results
  • FreeNet Liberec, for allowing access for data collection

10. Informative References

[IPTABLES-ECN]
Heist, P.G., "iptables-ecn GitHub Repository", <https://github.com/heistp/iptables-ecn/>.
[RFC1349]
Almquist, P., "Type of Service in the Internet Protocol Suite", RFC 1349, DOI 10.17487/RFC1349, , <https://www.rfc-editor.org/info/rfc1349>.
[RFC2481]
Ramakrishnan, K. and S. Floyd, "A Proposal to add Explicit Congestion Notification (ECN) to IP", RFC 2481, DOI 10.17487/RFC2481, , <https://www.rfc-editor.org/info/rfc2481>.
[RFC3168]
Ramakrishnan, K., Floyd, S., and D. Black, "The Addition of Explicit Congestion Notification (ECN) to IP", RFC 3168, DOI 10.17487/RFC3168, , <https://www.rfc-editor.org/info/rfc3168>.
[RFC3540]
Spring, N., Wetherall, D., and D. Ely, "Robust Explicit Congestion Notification (ECN) Signaling with Nonces", RFC 3540, DOI 10.17487/RFC3540, , <https://www.rfc-editor.org/info/rfc3540>.
[RFC3948]
Huttunen, A., Swander, B., Volpe, V., DiBurro, L., and M. Stenberg, "UDP Encapsulation of IPsec ESP Packets", RFC 3948, DOI 10.17487/RFC3948, , <https://www.rfc-editor.org/info/rfc3948>.
[RFC6040]
Briscoe, B., "Tunnelling of Explicit Congestion Notification", RFC 6040, DOI 10.17487/RFC6040, , <https://www.rfc-editor.org/info/rfc6040>.
[RFC8290]
Hoeiland-Joergensen, T., McKenney, P., Taht, D., Gettys, J., and E. Dumazet, "The Flow Queue CoDel Packet Scheduler and Active Queue Management Algorithm", RFC 8290, DOI 10.17487/RFC8290, , <https://www.rfc-editor.org/info/rfc8290>.
[RFC8311]
Black, D., "Relaxing Restrictions on Explicit Congestion Notification (ECN) Experimentation", RFC 8311, DOI 10.17487/RFC8311, , <https://www.rfc-editor.org/info/rfc8311>.
[WIREGUARD]
"WireGuard web site", <https://www.wireguard.com>.

Author's Address

Peter G. Heist
463 11 Liberec 30
Czech Republic