7. Traffic Filtering Actions
7. Traffic Filtering Actions
This document defines a minimum set of Traffic Filtering Actions that it standardizes as BGP Extended Communities [RFC4360]. This is not meant to be an inclusive list of all the possible actions but only a subset that can be interpreted consistently across the network. Additional actions can be defined as either requiring standards or as vendor specific.
The default action for a matching Flow Specification is to accept the packet (treat the packet according to the normal forwarding behavior of the system).
This document defines the following Extended Communities values shown in Table 8 in the form 0xttss, where tt indicates the type and ss indicates the sub-type of the Extended Community. Encodings for these Extended Communities are described below.
| community 0xttss | action | encoding |
|---|---|---|
| 0x8006 | traffic-rate-bytes (Section 7.1) | 2-octet AS, 4-octet float |
| 0x800c | traffic-rate-packets (Section 7.2) | 2-octet AS, 4-octet float |
| 0x8007 | traffic-action (Section 7.3) | bitmask |
| 0x8008 | rt-redirect AS-2octet (Section 7.4) | 2-octet AS, 4-octet value |
| 0x8108 | rt-redirect IPv4 (Section 7.4) | 4-octet IPv4 address, 2-octet value |
| 0x8208 | rt-redirect AS-4octet (Section 7.4) | 4-octet AS, 2-octet value |
| 0x8009 | traffic-marking (Section 7.5) | DSCP value |
Table 8: Traffic Filtering Action Extended Communities
Multiple Traffic Filtering Actions defined in this document may be present for a single Flow Specification and SHOULD be applied to the traffic flow (for example, traffic-rate-bytes and rt-redirect can be applied to packets at the same time). If not all of the Traffic Filtering Actions can be applied to a traffic flow, they should be treated as interfering Traffic Filtering Actions (see below).
Some Traffic Filtering Actions may interfere with each other or even contradict. Section 7.7 of this document provides general considerations on such Traffic Filtering Action interference. Any additional definition of Traffic Filtering Actions SHOULD specify the action to take if those Traffic Filtering Actions interfere (also with existing Traffic Filtering Actions).
All Traffic Filtering Actions are specified as transitive BGP Extended Communities.