MPLS WG K. Kompella
Internet-Draft W. Lin
Intended status: Standards Track Juniper Networks
Expires: January 13, 2022 July 12, 2021
No Further Fast Reroute
draft-kompella-mpls-nffrr-02
Abstract
There are several cases where, once Fast Reroute has taken place (for
MPLS protection), a second fast reroute is undesirable, even
detrimental. This memo gives several examples of this, and proposes
a mechanism to prevent further fast reroutes.
Status of This Memo
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Other Approaches . . . . . . . . . . . . . . . . . . . . 3
1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
2. Motivation . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1. EVPN (VPN/VPLS) Active-active Multihoming . . . . . . . . 3
2.2. RMR Protection . . . . . . . . . . . . . . . . . . . . . 4
2.3. General MPLS forwarding . . . . . . . . . . . . . . . . . 5
3. Solution . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.1. NFFRR for MPLS forwarding . . . . . . . . . . . . . . . . 6
3.2. Proposal . . . . . . . . . . . . . . . . . . . . . . . . 8
3.2.1. NFFRR and SPRING . . . . . . . . . . . . . . . . . . 10
3.3. NFFRR for MPLS Services . . . . . . . . . . . . . . . . . 10
3.4. NFFRR for RMR . . . . . . . . . . . . . . . . . . . . . . 11
4. Signaling NFFRR Capability . . . . . . . . . . . . . . . . . 12
4.1. Signaling NFFRR Capability for MPLS Services with BGP . . 12
4.2. Signaling NFFRR Capability for MPLS Services with
Targeted LDP . . . . . . . . . . . . . . . . . . . . . . 12
4.3. Signaling NFFRR Capability for MPLS Forwarding . . . . . 12
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
6. Security Considerations . . . . . . . . . . . . . . . . . . . 13
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 13
7.1. Normative References . . . . . . . . . . . . . . . . . . 13
7.2. Informative References . . . . . . . . . . . . . . . . . 14
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15
1. Introduction
MPLS Fast Reroute (FRR) [RFC4090] [RFC5286] [RFC7490] is a useful and
widely deployed tool for minimizing packet loss in the case of a link
or node failure. This has not only proven to be very effective, it
is often the reason for using MPLS as a data plane. FRR works for a
variety of control plane protocols, including LDP, RSVP-TE, and
SPRING. Furthermore, FRR is often used to protect MPLS services such
as IP VPN and EVPN.
Having said this, there are case where, once FRR has taken place, if
the packet encounters a second failure, a second FRR is not helpful,
perhaps even disruptive. For example, the packet may loop until TTL
expires. This can lead to link congestion and further packet loss.
Thus, the attempt to prevent a packet from being dropped may instead
affect many other packets. Note that the "second" failure may simply
be another manifestation of the same failure; see Figure 1.
This memo proposes a mechanism for preventing further FRR once in
cases where such further protection may be harmful. Several examples
where this is the case are demonstrated as motivation. A solution
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using special-purpose labels (SPLs) is then offered. Some mechanisms
for distributing the capability to avoid further fast reroutes are
also discussed, although these may be better placed in other
documents in other Working Groups.
1.1. Other Approaches
[ALDT] has a more elaborate mechanism for preventing loops due to
multiple failures. This involves marking the nodes redirecting
traffic in a header (either individually, or as node groups), and
dropping the packet at a transit node if its ID is in the header.
1.2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
2. Motivation
A few cases are given where "further fast reroute" is harmful. Some
of the cases are for MPLS services; others for "plain" MPLS
forwarding.
2.1. EVPN (VPN/VPLS) Active-active Multihoming
Consider the following topology for multihoming an Ethernet VPN (EVPN
[RFC7432]) Customer Edge (CE) device for protection against the
failure of a Provider Edge (PE) device or a PE-CE link. To do so,
there is a backup MPLS path between PE2 and PE3 (denoted by the
starred line).
P1 ... ... P3 --- PE2
/ * \ link1
/ * \
CE1 --- PE1 * CE2
\ * /
\ * / link2
P2 ... ... P4 --- PE3
Figure 1: EVPN Multihoming
Suppose (known unicast) traffic goes from CE1 to CE2. With active-
active multihoming, this traffic will be load-balanced between PE2
(to CE2 via link link1) and PE3 (to CE2 via link2). If link1 were to
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fail, PE2 can still get traffic for CE2 by sending it over the backup
path to PE3 (and similarly for PE3 if link2 fails).
However, suppose CE2 is down. PE2 will assume link1 is down and send
traffic for CE2 to PE3 over the backup path. PE3 (which thinks that
link2 is down; note that the single real failure of CE2 being down is
manifested as separate failures to PE2 and PE3) will protect this
"second" failure by sending traffic for CE2 over the backup path to
PE2. Thus, traffic will ping-pong between PE2 and PE3 until TTL
expires.
Thus, the attempt to protect traffic to CE2 may end up doing more
harm than good, by congesting the backup path between PE2 and PE3 and
by giving PE2 and PE3 useless work to do.
A similar topology can be used in EVPN-Etree [RFC8317], EVPN-VPWS
[RFC8214], IP VPN [RFC4364] or VPLS [RFC4761] [RFC4762]. In all
these cases, the same looping behavior would occur for unicast
traffic if CE2 is down.
2.2. RMR Protection
R0 . . . R1
. .
R7 R2
Anti- | . . |
Clockwise | . Ring . | Clockwise
v . . v
R6 R3
. .
R5 . . . R4
Figure 2: RMR Looping
In Resilient MPLS Rings (RMR), suppose traffic goes from a node, say
R0, to a node, say R4, over a clockwise path. Protection consists of
switching this traffic onto the anti-clockwise path to R4. This
works well if a node or link between R0 or R4 is down. However, if
node R4 itself is down, its adjacent neighbor R3, will send the
traffic anti-clockwise to R4; when this traffic reaches R4's other
neighbor R5, it will return to N3, and so on, until TTL expires.
[I-D.ietf-mpls-rmr] provides more details, and offers some means of
mitigation. This memo offers a more elegant solution.
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2.3. General MPLS forwarding
Consider the following topology:
N1 --- N2 --- N3 --- N4
| |
| |
N5 --- N6 --- N7 --- N8
| |
| |
N9 --- N10
Figure 3: General MPLS Forwarding
Say link protection is configured for links N2-N3 and N6-N7. Link
N2-N3 is protected by a bypass tunnel N2-N6-N7-N3, and link N7-N3 is
protected by a bypass tunnel N7-N6-N2-N3. (These bypass tunnels may
be set up using RSVP-TE [RFC3209] or via SPRING stacks [RFC8660].)
Say furthermore that there is an LSP from N1 to N4 with path
N1-N2-N3-N4, which asks for link protection. If link N2-N3 fails,
traffic will take the path N1-N2-N6-N7-N3-N4.
Suppose, however, links N2-N3 and N7-N3 fail simultaneously. This
may happen if they share fate (e.g., go over a common fiber conduit);
it may also appear to happen if node N3 fails. Either way, first,
the bypass protecting link N2-N3 kicks in, and traffic is sent to N3
via N6 and N7. However, when the traffic hits N7, the bypass for
N7-N3 kicks in, and traffic is sent back to N2. Thus the traffic
will loop between N2 and N7 until TTL expires, in the process
congesting links N2-N6 and N6-N7.
Now consider an LSP: N5-N6-N7-N8. The link N6-N7 may be protected by
the bypass N6-N2-N3-N7 or by N6-N9-N10-N7, or by load-balancing
between these two bypasses. If both links N2-N3 and N6-N7 fail, then
traffic that is protected via bypass N6-N2-N3-N7 will ping-pong
between N6 and N2 until TTL expires; traffic protected via bypass
N6-N9-N10-N7 will successfully make it to N8. If link N6-N7 is
protected by load-balancing across the two bypass paths, then about
half the traffic will loop between N6 and N2, and the rest will make
it to N8.
While the above description is for protection using a bypass tunnel,
the same principle applies to protection using Loop-Free Alternates
[RFC5286] [RFC7490] or any of its variants (such as Topology
Independent LFA).
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3. Solution
To address this issue, we suggest the use of a SPL [RFC7274] called
NFFRR (value TBD; suggested: 8). An alternate would be to use an
extended SPL, whereby a pair of labels indicates that no further fast
route is desired. However, in the case of SPRING MPLS bypass tunnels
(Section 3.2.1) of depth N, this would triple the label stack size.
Using regular SPLs instead would only double the stack size.
3.1. NFFRR for MPLS forwarding
To illustrate, we'll first take the example of Figure 3, with MPLS
paths signaled using RSVP-TE. This method can be used for paths that
use SPRING stacks, but this will be detailed in a later version.
N1 --- N2 --- N3 --- N4 LSP N1 to N4: L1->L2->null
| | Bypass for N2-N3: L3->L4->null
| | Bypass for N7-N3: L5->L6->null
N5 --- N6 --- N7 --- N8 LSP N5 to N8: L7->L8->null
| | Bypass1 for N6-N7: L9->L10->null
| | Bypass2 for N6-N7: L11->L12->null
N9 --- N10 (via N9-N10-N7)
Figure 4: Example Using RSVP-TE LSPs
+------+----------+------+----------+----------+
| Node | Action | Next | New Pkt | Comment |
+------+----------+------+----------+----------+
| N1 | push L1 | N2 | [L1] pkt | ingress |
| | | | | |
| N2 | L1 -> L2 | N3 | [L2] pkt | |
| | | | | |
| N3 | pop L2 | N4 | pkt | PHP |
| | | | | |
| N4 | fwd pkt | - | - | continue |
+------+----------+------+----------+----------+
Table 1: Forwarding from N1 to N4
Note 1: "[L1 ...]" denotes the label stack on the packet; pkt is the
original packet received at ingress. "L1 -> L2" means swap label L1
with L2. "pop L2" means pop the top label L2. "fwd pkt" means
forward the packet as usual.
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+------+----------+------+----------+---------+
| Node | Action | Next | New Pkt | Comment |
+------+----------+------+----------+---------+
| N2 | push L3 | N6 | [L3] pkt | ingress |
| | | | | |
| N6 | L3 -> L4 | N7 | [L4] pkt | |
| | | | | |
| N7 | pop L4 | N3 | pkt | PHP |
+------+----------+------+----------+---------+
Table 2: Forwarding over the bypass for link N2-N3
+------+----------+------+----------+---------+
| Node | Action | Next | New Pkt | Comment |
+------+----------+------+----------+---------+
| N7 | push L5 | N6 | [L5] pkt | ingress |
| | | | | |
| N6 | L5 -> L6 | N2 | [L6] pkt | |
| | | | | |
| N2 | pop L6 | N3 | pkt | PHP |
+------+----------+------+----------+---------+
Table 3: Forwarding over Bypass1 for link N7-N3
+------+----------+------+-------------+----------+
| Node | Action | Next | New Pkt | Comment |
+------+----------+------+-------------+----------+
| N1 | push L1 | N2 | [L1] pkt | ingress |
| | | | | |
| N2 | L1 -> L2 | N3 | [L2] pkt | N3 X |
| | | | | |
| N2 | push L3 | N6 | [L3 L2] pkt | PLR |
| | | | | |
| N6 | L3 -> L4 | N7 | [L4 L2] pkt | |
| | | | | |
| N7 | pop L4 | N3 | [L2] pkt | merge |
| | | | | |
| N3 | pop L2 | N4 | pkt | PHP |
| | | | | |
| N4 | fwd pkt | - | - | continue |
+------+----------+------+-------------+----------+
Table 4: Forwarding from N1 to N4 if link N2-N3 fails
Table 4 is obtained by composing Table 1 and Table 2.
Note 2: "N3 X" means "next hop N3 unavailable (because link N2-N3
failed)".
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+------+----------+------+-------------+---------+
| Node | Action | Next | New Pkt | Comment |
+------+----------+------+-------------+---------+
| N1 | push L1 | N2 | [L1] pkt | ingress |
| | | | | |
| N2 | L1 -> L2 | N3 | [L2] pkt | N3 X |
| | | | | |
| N2 | push L3 | N6 | [L3 L2] pkt | PLR |
| | | | | |
| N6 | L3 -> L4 | N7 | [L4 L2] pkt | |
| | | | | |
| N7 | pop L4 | N3 | [L2] pkt | N3 X' |
| | | | | |
| N7 | push L5 | N6 | [L5 L2] pkt | |
| | | | | |
| N6 | L5 -> L6 | N2 | [L6 L2] pkt | PLR |
| | | | | |
| N2 | pop L6 | N3 | [L2] pkt | N3 X |
| | | | | |
| N2 | push L3 | N6 | [L3 L2] | PLR |
| | | | | |
| etc | | | | loop! |
+------+----------+------+-------------+---------+
Table 5: Forwarding from N1 to N4 if links N2-N3 and N7-N3 fail
Table 5 is obtained by composing Table 1, Table 2 and Table 3.
Note 3: "N3 X'" means "next hop N3 unavailable because link N7-N3 is
down.
Note 4: While the impact of a loop is pretty bad, the impact of an
ever-growing label stack (not illustrated here) and possible
associated fragmentation on transit nodes may be worse.
3.2. Proposal
An LSR (typically a PLR) that wishes to prevent further FRRs after
the first one can push an SPL, namely NFFRR, onto the label stack as
follows:
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+------+----------------+------+-------------------+----------+
| Node | Action | Next | New Pkt | Comment |
+------+----------------+------+-------------------+----------+
| N1 | push L1 | N2 | [L1] pkt | ingress |
| | | | | |
| N2 | L1 -> L2 | N3 | [L2] pkt | N3 X |
| | | | | |
| N2 | push L3, NFFRR | N6 | [L3 NFFRR L2] pkt | PLR |
| | | | | |
| N6 | L3 -> L4 | N7 | [L4 NFFRR L2] pkt | |
| | | | | |
| N7 | pop L4, NFFRR | N3 | [L2] pkt | merge |
| | | | | |
| N3 | pop L2 | N4 | pkt | PHP |
| | | | | |
| N4 | fwd pkt | - | - | continue |
+------+----------------+------+-------------------+----------+
Table 6: Forwarding from N1 to N4 if link N2-N3 fails with NFFRR
Note 5: N2 can insert an NFFRR label only if it knows that all LSRs
in the path can process it correctly. See Section 4 for some details
on how this capability is communicated.
+------+----------------+------+-------------------+----------+
| Node | Action | Next | New Pkt | Comment |
+------+----------------+------+-------------------+----------+
| N1 | push L1 | N2 | [L1] pkt | ingress |
| | | | | |
| N2 | L1 -> L2 | N3 | [L2] pkt | N3 X |
| | | | | |
| N2 | push L3, NFFRR | N6 | [L3 NFFRR L2] pkt | PLR |
| | | | | |
| N6 | L3 -> L4 | N7 | [L4 NFFRR L2] pkt | |
| | | | | |
| N7 | pop L4 | N3 | [NFFRR L2] pkt | N3 X |
| | | | | |
| N7 | check NFFRR | - | - | drop pkt |
+------+----------------+------+-------------------+----------+
Table 7: Forwarding from N1 to N4 if links N2-N3 and N7-N3 fail with
NFFRR
Note 6: "check NFFRR" means that, before N7 applies FRR (because link
N7-N3 is down), N7 checks the label below the top label (or in this
case, because of PHP, the top label itself). If this is the NFFRR
label, N7 drops the packet rather than apply FRR.
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3.2.1. NFFRR and SPRING
Suppose that, to protect link N2-N3, a bypass tunnel N2-N6-N7-N3 were
instantiated using SPRING MPLS [RFC8660], in particular, using
adjacency SIDs. If the corresponding labels for links N6-N7 and
N7-N3 were L20 and L21, the bypass would consist of pushing the label
stack [L20 L21] onto the packet and sending the packet to N6. To
indicate that FRR has already occurred and to drop the packet rather
than to try to protect the packet again, N2 would have to push [L20
NFFRR L21 NFFRR] onto the packet before sending it to N6. If the
packet came from N1 with label L1, N2 would send a packet with label
stack [L20 NFFRR L21 NFFRR L2] to N6.
N6 would see L20, pop it, note the NFFRR label and pop it, then
attempt to send the packet to N7. If the link N6-N7 is down, N6
drops the packet. Otherwise, N7 gets the packet, sees L21, pops it,
sees NFFRR, pops it and tries to send the packet to N3. If link
N7-N3 is down, N7 drops the packet. Otherwise, N3 gets the packet
with L2, swaps with with L3 and sends it to N4.
Note that with SPRING MPLS, the NFFRR label needs to be repeated for
each label in the bypass stack. Hence the request for a "regular"
SPL rather than an extended SPL.
3.3. NFFRR for MPLS Services
First, we illustrate known unicast EVPN forwarding:
+------+-------------+-------+-------------+---------+
| Node | Action | Next | Packet | Comment |
+------+-------------+-------+-------------+---------+
| PE1 | send to CE2 | PE2 | [T1 S2] pkt | EVPN |
| | | | | |
| PE2 | send to CE2 | link1 | pkt | done! |
+------+-------------+-------+-------------+---------+
Note: T1/T2/T3 are the transport labels for PE1/PE3/PE2 to reach
PE2/PE2/PE3 respectively. S2/S3 are the service labels announced by
PE2/PE3 for CE2.
Then, we show what happens when CE2 is down without NFFRR:
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+------+-------------+-------+-------------+---------+
| Node | Action | Next | Packet | Comment |
+------+-------------+-------+-------------+---------+
| PE1 | send to CE2 | PE2 | [T1 S2] pkt | EVPN |
| | | | | |
| PE2 | send to CE2 | link1 | -- | link1 X |
| | | | | |
| PE2 | send to CE2 | PE3 | [T3 S3] pkt | eFRR |
| | | | | |
| PE3 | send to CE2 | link2 | -- | link2 X |
| | | | | |
| PE3 | send to CE2 | PE2 | [T2 S2] pkt | eFRR |
| | | | | |
| PE2 | send to CE2 | link1 | -- | link1 X |
| | | | | |
| PE2 | send to CE2 | PE3 | [T3 S3] pkt | eFRR |
| | | | | |
| ... | | | | loop! |
+------+-------------+-------+-------------+---------+
Note: link1/link2 X means link1/link2 is down. eFRR refers to EVPN
multihoming FRR.
In the case of MPLS services such as EVPN Figure 1, the NFFRR label
is inserted below the service label, as shown below:
+------+-------------+-------+-------------------+-------------+
| Node | Action | Next | Packet | Comment |
+------+-------------+-------+-------------------+-------------+
| PE1 | send to CE2 | PE2 | [T1 S2] pkt | EVPN |
| | | | | |
| PE2 | send to CE2 | link1 | -- | link1 X |
| | | | | |
| PE2 | send to CE2 | PE3 | [T3 S2 NFFRR] pkt | eFRR |
| | | | | |
| PE3 | send to CE2 | link2 | -- | link2 X |
| | | | | |
| PE3 | drop pkt | -- | -- | check NFFRR |
+------+-------------+-------+-------------------+-------------+
Note: "check NFFRR" is as above.
3.4. NFFRR for RMR
As described in Figure 2, packets will loop until TTL expires if the
destination node in an RMR ring (here, R4) fails. The solution in
this case is that the first node to apply RMR protection (R3) pops
the current RMR transport label being used, sees that the next label
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is not NFFRR (so protection is allowed), pushes an NFFRR label and
then the RMR transport label for the reverse direction.
When R5 receives the packet, it sees that the next link is down, pops
the RMR transport label, sees the NFFRR label and drops the packet.
Thus, the loop is avoided.
4. Signaling NFFRR Capability
4.1. Signaling NFFRR Capability for MPLS Services with BGP
The ideal choice would be an attribute consisting of a bit vector of
node capabilities, one bit of which would be the capability of
processing the NFFRR SPL below the BGP service label. This would be
used by BGP L2VPN, BGP VPLS, EVPN, E-Tree and E-VPWS. An alternative
is to use the BGP Capabilities Optional Parameter
[I-D.ietf-idr-next-hop-capability]. Details to be worked out.
4.2. Signaling NFFRR Capability for MPLS Services with Targeted LDP
One approach to signaling NFFRR capability for MPLS services signaled
with targeted LDP is to introduce a new LDP TLV called the NFFRR
Capability TLV as an Optional Parameter in the Label Mapping Message
[RFC5036]. This TLV has Type TBD (suggested: 0x0207) and Length 0.
Another approach is to use LDP Capabilities [RFC5561]; this approach
has the advantage that it deals with capabilities on a node basis
rather than on a per label mapping basis. However, there don't
appear to be other documents using this approach.
4.3. Signaling NFFRR Capability for MPLS Forwarding
The authors suggest signaling a router's ability to process the NFFRR
SPL using the Link State Router TE Node Capabilities [RFC5073], which
works for both IS-IS and OSPF. A new TE Node Capability bit, the N
bit (suggested value 5) indicates that the advertising node is
capable of processing the NFFRR SPL.
5. IANA Considerations
If this draft is deemed useful, a way to signal that No Further Fast-
route should be performed on a packet will be needed. There are two
approaches: allocate an SPL for NFFRR: if so, we suggest the early
allocation of label 8 for this. Alternatively, if
[I-D.kompella-mpls-mspl4fa] (or similar) is adopted, allocate a
forwarding action bit saying whether or not to do FRR.
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Furthermore, means of signaling the ability to process the NFFRR SPL/
bit should be defined for IS-IS, OSPF, LDP and BGP.
The following update is suggested for the Link State Router TE Node
Capabilities registry:
+-----+-------+---------------+
| Bit | Name | Reference |
+-----+-------+---------------+
| 5 | NFFRR | This document |
+-----+-------+---------------+
The following update is suggested for the TLV Type Name Space of the
Label Distribution Protocol (LDP) Parameters registry:
+--------+-------+---------------+
| Type | Name | Reference |
+--------+-------+---------------+
| 0x0207 | NFFRR | This document |
+--------+-------+---------------+
6. Security Considerations
A malicious or compromised LSR can insert NFFRR into a label stack,
preventing FRR from occurring. If so, protection will not kick in
for failures that could have been protected, and there will be
unnecessary packet loss.
7. References
7.1. Normative References
[I-D.kompella-mpls-mspl4fa]
Kompella, K., Beeram, V. P., Saad, T., and I. Meilik,
"Multi-purpose Special Purpose Label for Forwarding
Actions", draft-kompella-mpls-mspl4fa-00 (work in
progress), February 2021.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC5036] Andersson, L., Ed., Minei, I., Ed., and B. Thomas, Ed.,
"LDP Specification", RFC 5036, DOI 10.17487/RFC5036,
October 2007, <https://www.rfc-editor.org/info/rfc5036>.
Kompella & Lin Expires January 13, 2022 [Page 13]
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[RFC5073] Vasseur, J., Ed. and J. Le Roux, Ed., "IGP Routing
Protocol Extensions for Discovery of Traffic Engineering
Node Capabilities", RFC 5073, DOI 10.17487/RFC5073,
December 2007, <https://www.rfc-editor.org/info/rfc5073>.
[RFC7274] Kompella, K., Andersson, L., and A. Farrel, "Allocating
and Retiring Special-Purpose MPLS Labels", RFC 7274,
DOI 10.17487/RFC7274, June 2014,
<https://www.rfc-editor.org/info/rfc7274>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
7.2. Informative References
[ALDT] Merling, D., Braun, W., and M. Menth, "Efficient Data
Plane Protection for SDN", June 2018,
<https://atlas.informatik.uni-tuebingen.de/~menth/papers/
Menth18g.pdf>.
[I-D.ietf-idr-next-hop-capability]
Decraene, B., Kompella, K., and W. Henderickx, "BGP Next-
Hop dependent capabilities", draft-ietf-idr-next-hop-
capability-06 (work in progress), October 2020.
[I-D.ietf-mpls-rmr]
Kompella, K. and L. M. Contreras, "Resilient MPLS Rings",
draft-ietf-mpls-rmr-14 (work in progress), February 2021.
[RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,
and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001,
<https://www.rfc-editor.org/info/rfc3209>.
[RFC4090] Pan, P., Ed., Swallow, G., Ed., and A. Atlas, Ed., "Fast
Reroute Extensions to RSVP-TE for LSP Tunnels", RFC 4090,
DOI 10.17487/RFC4090, May 2005,
<https://www.rfc-editor.org/info/rfc4090>.
[RFC4364] Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private
Networks (VPNs)", RFC 4364, DOI 10.17487/RFC4364, February
2006, <https://www.rfc-editor.org/info/rfc4364>.
[RFC4761] Kompella, K., Ed. and Y. Rekhter, Ed., "Virtual Private
LAN Service (VPLS) Using BGP for Auto-Discovery and
Signaling", RFC 4761, DOI 10.17487/RFC4761, January 2007,
<https://www.rfc-editor.org/info/rfc4761>.
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[RFC4762] Lasserre, M., Ed. and V. Kompella, Ed., "Virtual Private
LAN Service (VPLS) Using Label Distribution Protocol (LDP)
Signaling", RFC 4762, DOI 10.17487/RFC4762, January 2007,
<https://www.rfc-editor.org/info/rfc4762>.
[RFC5286] Atlas, A., Ed. and A. Zinin, Ed., "Basic Specification for
IP Fast Reroute: Loop-Free Alternates", RFC 5286,
DOI 10.17487/RFC5286, September 2008,
<https://www.rfc-editor.org/info/rfc5286>.
[RFC5561] Thomas, B., Raza, K., Aggarwal, S., Aggarwal, R., and JL.
Le Roux, "LDP Capabilities", RFC 5561,
DOI 10.17487/RFC5561, July 2009,
<https://www.rfc-editor.org/info/rfc5561>.
[RFC7432] Sajassi, A., Ed., Aggarwal, R., Bitar, N., Isaac, A.,
Uttaro, J., Drake, J., and W. Henderickx, "BGP MPLS-Based
Ethernet VPN", RFC 7432, DOI 10.17487/RFC7432, February
2015, <https://www.rfc-editor.org/info/rfc7432>.
[RFC7490] Bryant, S., Filsfils, C., Previdi, S., Shand, M., and N.
So, "Remote Loop-Free Alternate (LFA) Fast Reroute (FRR)",
RFC 7490, DOI 10.17487/RFC7490, April 2015,
<https://www.rfc-editor.org/info/rfc7490>.
[RFC8214] Boutros, S., Sajassi, A., Salam, S., Drake, J., and J.
Rabadan, "Virtual Private Wire Service Support in Ethernet
VPN", RFC 8214, DOI 10.17487/RFC8214, August 2017,
<https://www.rfc-editor.org/info/rfc8214>.
[RFC8317] Sajassi, A., Ed., Salam, S., Drake, J., Uttaro, J.,
Boutros, S., and J. Rabadan, "Ethernet-Tree (E-Tree)
Support in Ethernet VPN (EVPN) and Provider Backbone
Bridging EVPN (PBB-EVPN)", RFC 8317, DOI 10.17487/RFC8317,
January 2018, <https://www.rfc-editor.org/info/rfc8317>.
[RFC8660] Bashandy, A., Ed., Filsfils, C., Ed., Previdi, S.,
Decraene, B., Litkowski, S., and R. Shakir, "Segment
Routing with the MPLS Data Plane", RFC 8660,
DOI 10.17487/RFC8660, December 2019,
<https://www.rfc-editor.org/info/rfc8660>.
Authors' Addresses
Kompella & Lin Expires January 13, 2022 [Page 15]
Internet-Draft NFFRR July 2021
Kireeti Kompella
Juniper Networks
1133 Innovation Way
Sunnyvale, CA 94089
United States
Email: kireeti.kompella@gmail.com
Wen Lin
Juniper Networks
1133 Innovation Way
Sunnyvale, CA 94089
United States
Email: wlin@juniper.net
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