Internet N. Shen
Internet-Draft C. Pignataro
Intended status: Standards Track R. Asati
Expires: August 30, 2012 E. Chen
Cisco Systems
A. Atlas
Juniper Networks
February 27, 2012
Traceroute and Ping Message Extension
draft-shen-traceroute-ping-ext-04
Abstract
This document specifies extensions to traceroute and ping techniques
to convey additional application information to be carried in UDP,
TCP and ICMP traceroute probe messages and ICMP echo request and
reply messages. The extensions are backward compatible.
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 http://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 August 30, 2012.
Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
Shen, et al. Expires August 30, 2012 [Page 1]
Internet-Draft Traceroute Ping Extension February 2012
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Specification of Requirements . . . . . . . . . . . . . . . . 3
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Trace-Ping Message Extension . . . . . . . . . . . . . . . . . 4
4.1. Trace-Ping Extension Structure . . . . . . . . . . . . . . 4
4.1.1. Trace-Ping Common Header . . . . . . . . . . . . . . . 4
4.1.2. Trace-Ping Object . . . . . . . . . . . . . . . . . . 5
4.1.2.1. Trace-Ping Authentication Object . . . . . . . . . 6
4.1.2.2. Trace-Ping Information-Request Object . . . . . . 7
4.2. Trace-Ping Extension Offset . . . . . . . . . . . . . . . 8
5. Trace-Ping Port Number . . . . . . . . . . . . . . . . . . . . 8
6. Scaling Considerations on Internet . . . . . . . . . . . . . . 8
6.1. Implementation and Operation Considerations . . . . . . . 8
7. Security Considerations . . . . . . . . . . . . . . . . . . . 9
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 10
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 10
10.1. Normative References . . . . . . . . . . . . . . . . . . . 10
10.2. Informative References . . . . . . . . . . . . . . . . . . 11
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 11
Shen, et al. Expires August 30, 2012 [Page 2]
Internet-Draft Traceroute Ping Extension February 2012
1. Specification of Requirements
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
2. Introduction
Traceroute and Ping are two most commonly used tools created since
the dawn of the Internet in the diagnosis of network problems. This
document proposes the mechanism by which the traceroute probe
messages and ICMP echo request/reply messages can be extended to
include other user information various applications may want to
include; and it can be optionally authenticated by the receiving
node(s). These mechanisms are intended for network operators to
perform more secured network management and troubleshooting tasks
while using traceroute and ping tools. The changes proposed in this
document are backward compatible (with the existing traceroute and
ping tools) and applicable to both IPv4 and IPv6 networks.
The mechanisms specified in this document apply to to the following
traceroute and ping probe protocols: UDP [RFC0768], TCP [RFC0793],
and ICMP/ICMPv6 [RFC0792] [RFC4443]. This mechanism also applies to
the ICMP/ICMPv6 echo reply messages [RFC0792].
This document defines an extension for traceroute and ping probe
messages to optionally include authentication signature object. The
intermediate and destination nodes can authenticate the sender of the
traceroute or ping packet before providing the requested information
in the ICMP response. This document also defines an optional
Information-Request Object for the traceroute/ping extension. This
Object specifies the types of information the sender expects to be
included in the traceroute/ping response (i.e., in the ICMP message
elicited by the traceroute/ping packet and generated by the
intermediate or destination node or nodes).
Other applications can define their own Trace-Ping objects using this
extension.
3. Motivation
The current traceroute or ping has no defined mechanism to include
application data on the sender side, or to include application data
in the ICMP echo reply on the receiver side. Although the [RFC4884]
has defined the multi-part message extension in ICMP, it is applied
only to the ICMP type 3, 11 and 12 for traceroute reply messages.
Shen, et al. Expires August 30, 2012 [Page 3]
Internet-Draft Traceroute Ping Extension February 2012
Those mechanisms are not applied to traceroute probe messages or ICMP
echo request/reply messages.
For security concerns of traceroute or ping packets, one may employ a
rudimentary control mechanism to limit the trusted senders by
defining on every router the access control lists specifying source
addresses of the traceroute and ping message, such mechanism is
deemed configuration intensive, static, and error-prone. Moreover,
such mechanism would be susceptible to address spoofing.
Additionally, such mechanism does not provide the sender with dynamic
control of the different kind of extensions to be requested.
The ICMP reply messages has been extended to support multi-part
message inside ICMP [RFC4884] for some ICMP types. Some of the
applications [RFC5837] [RFC4950] [I-D.shen-icmp-routing-inst] are
designed mainly for internal network troubleshooting by network
operators. Network providers may want to limit those applications
only to trusted senders of traceroute/ping probes due to security or
policy reasons by using this mechanism described in this document.
Other applications, for example the TRILL-OAM [I-D.tissa-trill-oam]
can use this scheme to extend their OAM application using ICMP echo
request and reply for data center troubleshootings.
4. Trace-Ping Message Extension
This proposed extension is to define a Trace-Ping data structure that
starts at a fixed location (i.e. the 64 octet) in the UDP/TCP/ICMP
probe packet data field.
4.1. Trace-Ping Extension Structure
The Trace-Ping structure starts in UDP/TCP/ICMP data field location
64th octet, see Section 4.2. It MUST have exactly one Trace-Ping
common header followed by zero or more Trace-Ping Objects.
4.1.1. Trace-Ping Common Header
The Common Header is a 8 octets structure has the following format:
Shen, et al. Expires August 30, 2012 [Page 4]
Internet-Draft Traceroute Ping Extension February 2012
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Version| Length | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Magic-Number (0x54726163) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The fields of the Common Header are defined as follows:
Version: 4 bits. It is defined as 1 in this document.
Length: 12 bits. The total length of the Trace-Ping data structure
specifying number of 32-bit words (includes the common
header and all the Objects).
Checksum: 16 bits. The one's complement of the one's complement sum
of the Trace-Ping data structure, with the checksum field
replaced by zero for the purpose of computing the checksum.
Magic Number: 32 bits. It is defined as Hex value of 0x54726163 in
this document. This is used mainly for structure
identification of this extension version.
4.1.2. Trace-Ping Object
Trace-Ping Object have the following format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Length | Class-Num | C-Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. // (object payload) // .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Length: 16 bits. Length of object, measured in octets, including
the object header and object payload.
Class-Num: 8 bits. Identifies ICMP Trace-Ping object class.
C-Type: 8 bits. Identifies ICMP Trace-Ping object sub-type.
All the Trace-Ping Objects are optional. This document defines two
Trace-Ping Objects below.
Shen, et al. Expires August 30, 2012 [Page 5]
Internet-Draft Traceroute Ping Extension February 2012
4.1.2.1. Trace-Ping Authentication Object
This Object carries the HMAC authentication related information. It
verifies both the data integrity and the authenticity of the entire
message. This Object has the following format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Length | Class-Num | C-Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Auth Type | Key ID | Auth Data Len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| Auth Data (Variable) |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ...
Length: Variable, in octets.
Class-Num: IANA allocation from ICMP Trace-Ping extension registry.
C-Type: 1
Auth Type: 16 bits. The following values are proposed:
* Type=0 signifies no authentication.
* Type=1 signifies simple password based authentication.
* Type=2 signifies Cryptographic authentication.
Please note that the above type values are in line with IANA
allocated values for other protocols (e.g., OSPF).
Key ID: 8 bits. This allows multiple secret keys to be active
simultaneously. Using Key IDs makes the key rollover
convenient. Each secret key must be associated with the
hash algorithm. This may be done through provisioning on
each node.
Auth Data Len: 8 bits. This specifies the length of the
authentication data (and allows for the support of current
and future authentication schemes).
Shen, et al. Expires August 30, 2012 [Page 6]
Internet-Draft Traceroute Ping Extension February 2012
Auth Data: Variable length. This field carries the result (e.g.,
HMAC code) of the HMAC algorithm applied over the entire
traceroute/ping IP/IPv6 packet. When the Auth data is
calculated, the shared key is stored in this field, and the
checksum fields in the IP header, UDP/TCP/ICMP header and
Trace-Ping common header are set to zero. The result of the
algorithm is placed in the Auth Key field. The following
lists algorithms that could be commonly supported:
* HMAC-MD5
* HMAC-SHA1
* HMAC-SHA2 variants (e.g., 224, 256, 384, 512, etc.)
At least HMAC-MD5 and HMAC-SHA1 algorithms should be
supported on all the nodes compliant with this
specification.
4.1.2.2. Trace-Ping Information-Request Object
This Information-Request Object is defined using a bitmap of 32-bits
field to represent an array of attributes. The attribute information
can be referenced in [RFC4950] [RFC5837]
[I-D.shen-icmp-routing-inst]. If detailed information needs to be
specified, new objects will have to be defined and it is outside the
scope of this document.
The Information-Request Object has the following format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Length | Class-Num | C-Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Info Request |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Length: 8
Class-Num: IANA allocation, the same Class-Num value as in
Section 4.1.2.1.
C-Type: 2
Shen, et al. Expires August 30, 2012 [Page 7]
Internet-Draft Traceroute Ping Extension February 2012
Info-Req: 32 bits. This bitflag field lists the request items the
probe sender is interested. The bit number ranges from the
right most bit to the left most bit. Currently defined as
the following:
Bit Number Information Item
0 MPLS label related attributes
1 Interface related attributes
2 IP/IPv6 address related attributes
3 Routing Instance related attributes
4 Nexthop(s) related attributes
4.2. Trace-Ping Extension Offset
The Trace-Ping Extension data structure starts at the fixed location
of 64th octet inside UDP, TCP and ICMP data field. The first 64
octets data is not defined and can be used by the probe packet
sender.
5. Trace-Ping Port Number
The Trace-Ping Port SHOULD be used for the UDP destination port, TCP
destination port or the ICMP echo request Identifier field with this
Trace-Ping extension. If the implementation uses the port field for
the packet sequence purposes, then the sequence information can be
written in the private space in the first 64 octets of the data field
in probe packets.
When the UDP or TCP, either in Traceroute or Ping operation, packet
reaches the destination, the host or router will return the ICMP
DESTINATION UNREACHABLE message back to the sender.
6. Scaling Considerations on Internet
Although this extension allows new features easily being developed on
top of the existing and popular Traceroute and Ping applications, it
does create challenges on the Internet as how to distinguish the
regular Traceroute and Ping packets from the new feature usages
without incurring rather substantial resource overhead. Steps need
to be taken on both implementation and operational sides.
6.1. Implementation and Operation Considerations
Implementation of this extension SHOULD use configuration knobs to
enable the new features on the device and leave the standard behavior
of Traceroute and Ping treatment if the explicit configuration for
Shen, et al. Expires August 30, 2012 [Page 8]
Internet-Draft Traceroute Ping Extension February 2012
this extension is not present.
The probe sender SHOULD use the Trace-Ping Port in their UDP and TCP
Traceroute or Ping packets when using this extension; and the probe
sender SHOULD use the Trace-Ping Port in the Identifier of ICMP echo
request packet. This will allow the receiver side to easily identify
the new features the network wants to support.
Implementation SHOULD allow filters or access-list mechanism to be
attached to this extension configurations. For example, the checking
or verifying the existence of this extension in the probe packets is
only performed when the probe packet is sourced from certain network
prefix range. Different features using this extension MAY have
different filters or access-lists.
Although this extension allows Traceroute and Ping packets to be
rate-limited just as the regular packets, the implementation SHOULD
apply special rate-limit if the feature is configured. This special
rate-limit SHOULD be configurable due to the nature of the features,
the device resource consumption of the features and the handling of
DoS attacks. The default special rate-limit SHOULD not exceeds the
rate-limit of regular Traceroute and Ping operations on the device.
On the prober packet or the sender side, implementation SHOULD allow
specifying the requested information, thus only a subset of the
regular objects need to be included in the replying ICMP packets when
the receiver is configured to support this feature.
7. Security Considerations
This extension enhances the security of traceroute and ping operation
in a backwards-compatible fashion. The mechanism allows the receiver
to verify the sender of the traceroute/ping packet such that certain
sensitive application, interface and network related information can
be supplied in the internal network or across trusted networks.
The use of Cryptographic authentication (i.e., an Auth Type value of
2) allows for a strong authentication mechanism since the keys cannot
be discerned by intercepting the packets. The proposed Keyed
authentication does not prevent replay attacks. However, in the case
of replay attacks, since the packet source IP/IPv6 address of the
traceroute/ping probe can not be changed, there is no easy way for
the attacker to retrieve the ICMP messages.
A router needs to protect against purposefully-bogus Traceroute
packets with extensions that fail the authentication, as a high rate
of messages can require significant processing time. [RFC1812]
Shen, et al. Expires August 30, 2012 [Page 9]
Internet-Draft Traceroute Ping Extension February 2012
specifies how rate-limiting is applied to the generation of ICMP
messages, and this rate-limiting deters the threat when applied
before checking the Authentication. Additionally, when using
Cryptographic authentication, the HMAC includes the source IP
address, which means the HMAC will not validate if the traceroute/
ping packet is sent over a NAT.
8. IANA Considerations
The IANA is requested to assign a well-known port number, Trace-Ping
Port, for the UDP and TCP of this Trace-Ping extensions.
The IANA is also requested to allocate the same Trace-Ping Port to be
used for the Identifier in the ICMP Echo Request with this Trace-Ping
extensions.
The Trace-Ping Extension contains Trace-Ping Objects. IANA is
requested to assign a new Class-Num for the Trace-Ping extension, and
a sub-registry under Trace-Ping extension to include c-types. This
document has defined c-type 1 and 2 for authentication and
information-request objects. c-types 3-0xF6 are allocated through
Expert Review [RFC5226]. C-types 0xF7 to 0xFF are reserved for
private use.
IANA should also establish a registry for Trace-Ping Info-Request
Bits under the information-request sub-registry. This document
defines bits 0 - 5 in Section 4.1.2.2. Bits 6-29 are allocated
through Expert Review. Bits 30 - 31 are reserved for private use.
9. Acknowledgements
Many thanks to Dan Wing, Tony Li, and Tissa Senevirathne for their
insightful comments and valuable suggestions regarding this document.
Many thanks to Ron Bonica, Thomas Narten, Jared Mauch, Warren Kumari,
Wes George, Shane Amante, S. Moonesamy who have made operational and
design comments and suggestions in particular to the scaling issues
on the Internet.
10. References
10.1. Normative References
[RFC0768] Postel, J., "User Datagram Protocol", STD 6, RFC 768,
August 1980.
Shen, et al. Expires August 30, 2012 [Page 10]
Internet-Draft Traceroute Ping Extension February 2012
[RFC0792] Postel, J., "Internet Control Message Protocol", STD 5,
RFC 792, September 1981.
[RFC0793] Postel, J., "Transmission Control Protocol", STD 7,
RFC 793, September 1981.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
10.2. Informative References
[I-D.shen-icmp-routing-inst]
Shen, N. and E. Chen, "ICMP Extensions for Routing
Instances", draft-shen-icmp-routing-inst-00 (work in
progress), November 2006.
[I-D.tissa-trill-oam]
Senevirathne, T., Dutt, D., Manral, V., and S. Aldrin,
"ICMP based OAM Solution for TRILL",
draft-tissa-trill-oam-03 (work in progress), January 2012.
[RFC1812] Baker, F., "Requirements for IP Version 4 Routers",
RFC 1812, June 1995.
[RFC4443] Conta, A., Deering, S., and M. Gupta, "Internet Control
Message Protocol (ICMPv6) for the Internet Protocol
Version 6 (IPv6) Specification", RFC 4443, March 2006.
[RFC4884] Bonica, R., Gan, D., Tappan, D., and C. Pignataro,
"Extended ICMP to Support Multi-Part Messages", RFC 4884,
April 2007.
[RFC4950] Bonica, R., Gan, D., Tappan, D., and C. Pignataro, "ICMP
Extensions for Multiprotocol Label Switching", RFC 4950,
August 2007.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226,
May 2008.
[RFC5837] Atlas, A., Bonica, R., Pignataro, C., Shen, N., and JR.
Rivers, "Extending ICMP for Interface and Next-Hop
Identification", RFC 5837, April 2010.
Shen, et al. Expires August 30, 2012 [Page 11]
Internet-Draft Traceroute Ping Extension February 2012
Authors' Addresses
Naiming Shen
Cisco Systems
225 West Tasman Drive
San Jose, CA 95134
USA
Email: naiming@cisco.com
Carlos Pignataro
Cisco Systems
7200 Kit Creek Road
Research Triangle Park, NC 27709
USA
Email: cpignata@cisco.com
Rajiv Asati
Cisco Systems
7025 Kit Creek Road
Research Triangle Park, NC 27709
USA
Email: rajiva@cisco.com
Enke Chen
Cisco Systems
170 West Tasman Drive
San Jose, CA 95134
USA
Email: enkechen@cisco.com
Alia K. Atlas
Juniper Networks
10 Technology Park Drive
Westford, MA 01886
USA
Email: akatlas@juniper.net
Shen, et al. Expires August 30, 2012 [Page 12]