If the switch experiences loss of IPv6 connectivity, use the following
procedure to troubleshoot the issue.
Procedure
-
Enter Global Configuration mode:
enable
configure
terminal
- Through the command
line interface, make sure the required routes are in place and the
corresponding neighbor entries are resolved (that is, in REACHABLE,
PROBE, DELAY or STALE state).
- INCOMPLETE neighbor
state indicates a problem if the corresponding neighbor is used by
some of the IPv6 routes. This applies to neighbor entries with link-local
addresses.
Note
Global addresses are not normally used as next hops. Having a global IPv6
neighbor entry as INCOMPLETE does not usually lead to a connectivity
issue.
- If the corresponding
route is not in place then this is a routing issue. If the neighbor
is not present or is INCOMPLETE, then further debugging is needed
on the network level (that is, the state of other nodes needs to be
examined).
- Disabling and re-enabling
IPv6 on the VLAN often recovers connectivity.
- Display the RSMLT and
MLT status:
show
ip rsmlt
show
mlt
Make sure the RSMLT peer MAC is learned and the IST state is ist.
