One document matched: draft-ietf-idr-flow-spec-v6-07.xml
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<rfc category="std" docName="draft-ietf-idr-flow-spec-v6-07.txt" ipr="trust200902">
<front>
<title abbrev="FlowSpec V6">Dissemination of Flow Specification Rules for IPv6</title>
<author fullname=" Danny McPherson " initials="D" surname="McPherson">
<organization>Verisign, Inc.</organization>
<address>
<postal>
<street></street>
<city></city>
<region></region>
<code></code>
<country></country>
</postal>
<email>dmcpherson@verisign.com</email>
</address>
</author>
<author fullname='Robert Raszuk' initials='R' surname='Raszuk' role="editor">
<organization>Bloomberg LP</organization>
<address>
<postal>
<street>731 Lexington Ave </street>
<city>New York City</city>
<region>NY</region>
<code>10022</code>
<country>USA</country>
</postal>
<email>robert@raszuk.net</email>
</address>
</author>
<author fullname="Burjiz Pithawala" initials="B" surname="Pithawala">
<organization>Individual</organization>
<address>
<postal>
<street></street>
<city></city>
<region></region>
<code></code>
<country></country>
</postal>
<email>burjizp@gmail.com</email>
</address>
</author>
<author fullname="Andy Karch" initials="A" surname="Karch">
<organization>Cisco Systems</organization>
<address>
<postal>
<street>170 West Tasman Drive</street>
<city>San Jose</city>
<region>CA</region>
<code>95134</code>
<country>USA</country>
</postal>
<email>akarch@cisco.com</email>
</address>
</author>
<author role="editor" fullname="Susan Hares" initials="S" surname="Hares">
<organization>Huawei</organization>
<address>
<postal>
<street>7453 Hickory Hill</street>
<city>Saline</city>
<region>MI</region>
<code>48176</code>
<country>USA</country>
</postal>
<email>shares@ndzh.com</email>
</address>
</author>
<date year="2016" />
<area>Routing Area</area>
<workgroup>IDR Working Group</workgroup>
<keyword>RFC</keyword>
<keyword>Request for Comments</keyword>
<keyword>I-D</keyword>
<keyword>Internet-Draft</keyword>
<keyword>BGP Flow Flow Specification</keyword>
<keyword>V6</keyword>
<abstract>
<t>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.
</t>
<t>
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.
</t>
</abstract>
</front>
<middle>
<section anchor="intro" title="Introduction">
<t> 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.
</t>
<t>
In this document authors analyze the differences of IPv6 <xref target="RFC2460"></xref>
flows description from those of traditional IPv4 packets and propose
subset of new encoding formats to enable Dissemination of Flow
Specification Rules <xref target="RFC5575"></xref> for IPv6.
</t>
<t>
This specification should be treated as an extension of base
<xref target="RFC5575"></xref> 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.
</t>
</section>
<section title="IPv6 Flow Specification encoding in BGP">
<t>
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.
</t>
<t>
This document will redefine the <xref target="RFC5575"></xref> SAFIs in order to make them
AFI specific and applicable to both IPv4 and IPv6 applications.
</t>
<t>
The following changes are defined:
<list>
<t> "SAFI 133 for IPv4 dissemination of flow specification rules" to
now be defined as "SAFI 133 for dissemination of unicast flow
specification rules"
</t>
<t> "SAFI 134 for VPNv4 dissemination of flow specification rules" to
now be defined as "SAFI 134 for dissemination of L3VPN flow
specification rules"
</t>
</list>
</t>
<t>
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.
</t>
<t>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.
<list>
<t>Flow specification received over AFI/SAFI=1/133 will be validated
against routing reachability received over AFI/SAFI=1/1
</t>
<t>Flow specification received over AFI/SAFI=1/134 will be validated
against routing reachability received over AFI/SAFI=1/128
</t>
<t> Flow specification received over AFI/SAFI=2/133 will be validated
against routing reachability received over AFI/SAFI=2/1
</t>
<t>Flow specification received over AFI/SAFI=2/134 will be validated
against routing reachability received over AFI/SAFI=2/128
</t>
</list>
</t>
</section>
<section title="IPv6 Flow Specification types changes">
<t> 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 <xref target="RFC5575"></xref> apply to IPv6 packets as is.
<list style="hanging">
<t hangText="Type 1 - Destination IPv6 Prefix ">
<list>
<t>Encoding: <type (1 octet), prefix length (1 octet), prefix offset
(1 octet), prefix>
</t>
<t>Function: Defines the destination prefix to match. Prefix offset has been
defined to allow for flexible matching on part of the IPv6 address
where we want to skip (don't care) of N first bits of the address.
This can be especially useful where part of the IPv6 address
consists of an embedded IPv4 address and matching needs to happen
only on the embedded IPv4 address. The encoded prefix contains
enough octets for the bits used in matching (length minus offset
bits).
</t>
</list>
</t>
<t hangText="Type 2 - Source IPv6 Prefix ">
<list>
<t>Encoding: <type (1 octet), prefix length (1 octet), prefix offset
(1 octet), prefix>
</t>
<t>Function: Defines the source prefix to match. Prefix offset has been
defined to allow for flexible matching on part of the IPv6 address
where we want to skip (don't care) of N first bits of the address.
This can be especially useful where part of the IPv6 address
consists of an embedded IPv4 address and matching needs to happen
only on the embedded IPv4 address. The encoded prefix contains
enough octets for the bits used in matching (length minus offset
bits)
</t>
</list>
</t>
<t hangText="Type 3 - Next Header">
<list>
<t>Encoding: <type (1 octet), [op, value]+>
</t>
<t>Function: Contains a set of {operator, value} pairs that are used to match
the last Next Header value octet in IPv6 packets. The operator
byte is encoded as specified in component type 3 of <xref target="RFC5575"></xref>.
</t>
<t>Note: While IPv6 allows for more then one Next Header field in the
packet the main goal of Type 3 flow specification component is to
match on the subsequent IP protocol value. Therefor the
definition is limited to match only on last Next Header field in
the packet.
</t>
</list>
</t>
<t hangText="Type 12 - Fragment">
<list>
<t> Encoding: <type (1 octet), [op, bitmask]+>
</t>
<t>
Uses bitmask operand format defined above. Bit-7 is not used and
MUST be 0 to provide backwards-compatibility with the definition
in <xref target="RFC5575"></xref>
</t>
<t>Bitmast operand format:
<figure>
<artwork>
0 1 2 3 4 5 6 7
+---+---+---+---+---+---+---+---+
| Reserved |LF |FF |IsF| 0 |
+---+---+---+---+---+---+---+---+
</artwork>
</figure>
</t>
<t>
Bitmask values:
<list style="symbols">
<t>Bit 6 - Is a fragment (IsF)</t>
<t>Bit 5 - First fragment (FF)</t>
<t>Bit 4 - Last fragment (LF)</t>
</list>
</t>
</list>
</t>
<t hangText="Type 13 - Flow Label (New type)">
<list>
<t>Encoding: <type (1 octet), [op, bitmask]+>
</t>
<t> Function: Contains a set of {operator, value} pairs that are used to match
the 20-bit Flow Label field <xref target="RFC2460"></xref>. The operator byte is
encoded as specified in the component type 3 of <xref target="RFC5575"></xref>. Values
are encoded as 1-, 2-, or 4- byte quantities.
</t>
</list>
</t>
</list>
</t>
<t> 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.
<figure>
<artwork>
+---------------------------+-------------+-------------------------+
| destination | source | port |
+---------------------------+-------------+-------------------------+
| 0x01 68 50 12 34 56 78 9A | 02 00 08 c0 | 04 03 89 45 8b 91 1f 90 |
+---------------------------+-------------+-------------------------+
</artwork>
</figure>
</t>
<section title="Order of Traffic Filtering Rules">
<t>
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.
</t>
<t>
<figure>
<artwork>
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;
}
</artwork>
</figure>
</t>
</section>
</section>
<section title="IPv6 Flow Specification Traffic Filtering Action changes">
<t>One of the traffic filtering actions which can be expressed by BGP
extended community is defined in <xref target="RFC5575"></xref> as traffic-marking.
Another traffic filtering action defined in <xref target="RFC5575"></xref> 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.
</t>
<t>Therefore, for the purpose of making it compatible with IPv6 header action
expressed by presence of the extended community the following text
in <xref target="RFC5575"></xref> has been modified to read:
<list style="hanging">
<t hangText="Traffic Marking (0x8009): "> The traffic marking extended community instructs a
system to modify first 6 bits of Traffic Class field as (recommended
by <xref target="RFC2474"></xref>) of a transiting IPv6 packet to the corresponding value.
This extended community is encoded as a sequence of 42 zero bits
followed by the 6 bits overwriting DSCP portion of Traffic Class
value.
</t>
<t hangText="Redirect-IPv6 (0x800B):"> redirect IPv6 address specific extended community
allows the traffic to be redirected to a VRF routing instance that
lists the specified IPv6 address specific route-target in its import
policy. If several local instances match this criteria, the choice
between them is a local matter (for example, the instance with the
lowest Route Distinguisher value can be elected). This extended
community uses the same encoding as the IPv6 address specific Route
Target extended community <xref target="RFC5701"></xref>.
</t>
</list>
</t>
</section>
<section title="Security Considerations">
<t> No new security issues are introduced to the BGP protocol by this
specification over the security concerins in
<xref target="RFC5575"></xref>
</t>
</section>
<section anchor="IANA" title="IANA Considerations">
<t>This section complies with <xref target="RFC7153"></xref>
</t>
<t>
IANA is requested to rename currently defined SAFI 133 and SAFI 134
per [RFC5575] to read:
<figure>
<artwork>
133 Dissemination of flow specification rules
134 L3VPN dissemination of flow specification rules
</artwork>
</figure>
</t>
<t>
IANA is requested to create and maintain a new registry entitled:
"Flow Spec IPv6 Component Types". The initial values are:
<figure>
<artwork>
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]
</artwork>
</figure>
</t>
</section>
<section title="Acknowledgements">
<t>Authors would like to thank Pedro Marques, Hannes Gredler and Bruno
Rijsman, Brian Carpenter, and Thomas Mangin for their valuable input.
</t>
</section>
</middle>
<back>
<references title="Normative References">
&RFC2119;
&RFC2460;
&RFC2474;
&RFC4271;
&RFC5492;
&RFC5575;
&RFC6437;
&RFC5701;
&RFC7153;
</references>
<references title="Informative References">
&RFC5095;
</references>
</back>
</rfc>| PAFTECH AB 2003-2026 | 2026-04-24 02:57:21 |