| IDR Working Group | D. McPherson |
| Internet-Draft | Verisign, Inc. |
| Intended status: Standards Track | R. Raszuk, Ed. |
| Expires: September 14, 2017 | Bloomberg LP |
| B. Pithawala | |
| Individual | |
| A. Karch | |
| Cisco Systems | |
| S. Hares, Ed. | |
| Huawei | |
| March 13, 2017 |
Dissemination of Flow Specification Rules for IPv6
draft-ietf-idr-flow-spec-v6-08.txt
Dissemination of Flow Specification Rules [RFC5575] provides a protocol extension for propagation of traffic flow information for the purpose of rate limiting or filtering. The [RFC5575] specifies those extensions for IPv4 protocol data packets.
This specification extends the current [RFC5575] and defines changes to the original document in order to make it also usable and applicable to IPv6 data packets.
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 September 14, 2017.
Copyright (c) 2017 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 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.
The growing amount of IPv6 traffic in private and public networks requires the extension of tools used in the IPv4 only networks to be also capable of supporting IPv6 data packets.
In this document authors analyze the differences of IPv6 [RFC2460] flows description from those of traditional IPv4 packets and propose subset of new encoding formats to enable Dissemination of Flow Specification Rules [RFC5575] for IPv6.
This specification should be treated as an extension of base [RFC5575] specification and not its replacement. It only defines the delta changes required to support IPv6 while all other definitions and operation mechanisms of Dissemination of Flow Specification Rules will remain in the main specification and will not be repeated here.
The [RFC5575] defines a new SAFIs (133 for IPv4) and (134 for VPNv4) applications in order to carry corresponding to each such application flow specification.
This document will redefine the [RFC5575] SAFIs in order to make them AFI specific and applicable to both IPv4 and IPv6 applications.
The following changes are defined:
For both SAFIs the indication to which address family they are referring to will be recognized by AFI value (AFI=1 for IPv4 or VPNv4, AFI=2 for IPv6 and VPNv6 respectively). Such modification is fully backwards compatible with existing implementation and production deployments.
It needs to be observed that such choice of proposed encoding is compatible with filter validation against routing reachability information as described in section 6 of RFC5575. Validation tables will now be performed according to the following rules.
0 1 2 3 4 5 6 7
+---+---+---+---+---+---+---+---+
| Reserved |LF |FF |IsF| 0 |
+---+---+---+---+---+---+---+---+
The following component types are redefined or added for the purpose of accommodating new IPv6 header encoding. Unless otherwise stated all other types as defined in [RFC5575] apply to IPv6 packets as is.
+-------------------------+------------+-----------------------+ | destination | source | port | +-------------------------+----------- +-----------------------+ |0x01 68 50 12 34 56 78 9A| 02 00 08 c0|04 03 89 45 8b 91 1f 90| +-------------------------+------------+-----------------------+
The following example demonstrates the new prefix encoding for: "all packets to ::1234:5678:9A00:0/64-104 from 192::/8 and port {range [137, 139] or 8080}". In the destination prefix, "80-" represents the prefix offset of 80 bits. In this exmaple, the 0 offset is omitted from the printed source prefix.
The orignal definition for the order of traffic filtering rules can be reused with new consideration for the IPv6 prefix offset. As long as the offsets are equal, the comparison is the same, retaining longest-prefix-match semantics. If the offsets are not equal, the lowest offset has precedence, as this flow matches the most significant bit.
Pseudocode
flow_rule_v6_cmp (a, b)
{
comp1 = next_component(a);
comp2 = next_component(b);
while (comp1 || comp2) {
// component_type returns infinity on end-of-list
if (component_type(comp1) < component_type(comp2)) {
return A_HAS_PRECEDENCE;
}
if (component_type(comp1) > component_type(comp2)) {
return B_HAS_PRECEDENCE;
}
if (component_type(comp1) == IPV6_DESTINATION || IPV6_SOURCE) {
// offset not equal, lowest offset has precedence
// offset equal ...
common_len = MIN(prefix_length(comp1), prefix_length(comp2));
cmp = prefix_compare(comp1, comp2, offset, common_len);
// not equal, lowest value has precedence
// equal, longest match has precedence
} else {
common =
MIN(component_length(comp1), component_length(comp2));
cmp = memcmp(data(comp1), data(comp2), common);
// not equal, lowest value has precedence
// equal, longest string has precedence
}
}
return EQUAL;
}
One of the traffic filtering actions which can be expressed by BGP extended community is defined in [RFC5575] as traffic-marking. Another traffic filtering action defined in [RFC5575] as a BGP extended community is redirect. To allow an IPv6 address specific route-target, a new traffic action IPv6 address specific extended community is provided.
Therefore, for the purpose of making it compatible with IPv6 header action expressed by presence of the extended community the following text in [RFC5575] has been modified to read:
No new security issues are introduced to the BGP protocol by this specification over the security concerins in [RFC5575]
This section complies with [RFC7153]
133 Dissemination of flow specification rules
134 L3VPN dissemination of flow specification rules
IANA is requested to rename currently defined SAFI 133 and SAFI 134 per [RFC5575] to read:
Type Description RFC --------------------------------- --------- Type 1 - Destination IPv6 Prefix [this draft] Type 2 - Source IPv6 Prefix [this draft] Type 3 - Next Header [this draft] Type 4 - Port [this draft] Type 5 - Destination port [this draft] Type 6 - Source port [this draft] Type 7 - ICMP type [this draft] Type 8 - ICMP code [this draft] Type 9 - TCP flags [this draft] Type 10 - Packet length [this draft] Type 11 - DSCP [this draft] Type 12 - Fragment [this draft] Type 13 - Flow Label [this draft]
IANA is requested to create and maintain a new registry entitled: "Flow Spec IPv6 Component Types". The initial values are:
Authors would like to thank Pedro Marques, Hannes Gredler and Bruno Rijsman, Brian Carpenter, and Thomas Mangin for their valuable input.
| [RFC5095] | Abley, J., Savola, P. and G. Neville-Neil, "Deprecation of Type 0 Routing Headers in IPv6", RFC 5095, DOI 10.17487/RFC5095, December 2007. |