I also posted this query in Cisco Community > Technology and Support > Networking > Routing but thinkit might be better here under XR OS specific questions.
I have a query on which statement is true regarding using hsrp group id's >255 in the doc
"IP Addresses and Services Configuration Guide for Cisco NCS 540 Series Routers, IOS XR Release 7.11.x"
https://www.cisco.com/c/en/us/td/docs/iosxr/ncs5xx/ipaddress/711x/b-ip-addresses-cg-711x-ncs540/implementing-hsrp.html#concept_ukj_p2c_gvb
The 'Expanded Group Number Range with HSRP Version 2' section
says it is supported in versions post 7.8.1 :-
"You can now use the group number range from 0 to 4095 for HSRP version 2.
...
It allows to interoperate with other routers that support this group number range."
This is important because we have ASR1k's in place that these are replacing and we need them to work with one another whilst we migrate.
But in section
"Configuring a Primary Virtual IPv4 Address"
the documentation says the restriction from earlier versions are still in place :-
The HSRP version 2 extended group range must be restricted to 0-255, even though the configuration up to 0-4095 is accepted.
The same restriction is also noted in
"Configuring a Secondary Virtual IPv4 Address"
and
"Configuring an HSRP Session Name"
Which is true ?
I have a customer environment where incumbent ASR1k's have hsrp groups > 255.
I tried to implemement this on 7.7.2 (which according to the table was not supported) and saw a new hsrp group in 'show hsrp brief' with id 3 as well as the >255 group id.
HSRP peer relationships did not form, and group 3 became HSRP Active with an unknown group address.
Interface Grp Pri P State Active addr Standby addr Group addr
BE1.992 3 100 Init 192.168.10.178 unknown unknown
BE1.992 292 69 Init unknownunknown 192.168.10.180
Will it be supported on 7.11.x ??
Do I have to use the workaround of making the group id <=255 ?
