Overview

Fast Path Forwarding IPv6 provides IPv6 forwarding in the fast path.

Features

Fast path forwarding IPv6 features:

• IP forwarding

• IP fragmentation

• ECMP (Equal Multipath) with priority per route type

• VRF support

• IPv6 reverse path forwarding check

• TCPmss clamping per interface

• Next hop marking (if the fast path filter module is present)

• Routes to same destination with different metrics

• Segment routing header processing and SRv6 route

Dependencies

Modules

• Fast Path Forwarding IPv4

Linux

• Synchronization of interface flag status forwarding is a kernel patch (upstream 3.8).

  Without this patch, the fast path starts with forwarding enabled.

  rtnl/ipv6: use netconf msg to advertise forwarding status

  http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=f3a1bfb

• ECMP IPv6 appeared in Linux 3.8

  http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=51ebd31

  http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=52bd4c0

  http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=b3ce5ae

  http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=1a72418

• Optimization of synchronization of NDP entries is a kernel patch (upstream 3.13).

  Without this patch, the NDP entries stand in state STALE and the fast path continuously sends hitflags for them.

  http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=53385d2d1de84f4036a0919ec46964c4e81b83f5

• Segment routing processing and SEG6 Route appeared first in Linux 4.10, SEG6LOCAL route appeared in Linux 4.14.

  SEG6 mode supported: inline, encap, l2encap

  SEG6LOCAL action supported: End, End.DX2, End.B6, End.B6.Encaps