BFD Path Consistency over SR
New H3C Technologies
China Mobile
China Mobile
ZTE Corporation
Bidirectional Forwarding Detection (BFD) can be used to monitor
paths between nodes.
U-BFD defined in [I-D.ietf-bfd-unaffiliated-echo] can effectively
reduce the device equipment.
Seamless BFD (S-BFD) provides a simplified mechanism which is
suitable for monitoring of paths that are setup dynamically and on a
large scale network.
In SR network, BFD can also be used to monitor SR paths. When a
headend use BFD to monitor the segment list/CPath of SR Policy, the
forward path of control packet is indicated by segment list, the
reverse path of response control packet is via the shortest path
from the reflector back to the initiator (headend) as determined by
routing. The forward path and reverse path of control packet are
likely inconsistent going through different intermediate nodes or
links.
This document describes a method to keep the forward path and
reverse path consistent when using S-BFD or U-BFD to detect SR
Policy