Alcatel-Lucent 7450 ESS Series, Configuration Manual

Page: 56 / 540

Page 56 7450 ESS OS Router Configuration Guide
BFD Over LAG and VSM Interfaces
A second application for a central BFD implementation is so BFD can be supported over LAG or
VSM interface. This is useful where BFD is not used for link failure detection but instead for node
failure detection. In this application, the BFD session can run between the IP interfaces associated
with the LAG or VSM interface, but there is only one session between the two nodes. There is no
requirement for the message flow to across a certain link, or VSM, to get to the remote node.
Figure 11: BFD over LAG
Fig_32A
Note:
In this case BFD is run between the
IES interfaces independent
of the LAG or its members
BFD
BFD BFD
L2 Switch
IES
LAG i/f LAG i/f
LAG i/f
IES
IES
2 2
4