On 5/4/21 03:28, Adam Thompson wrote:
Hey, just checking as I don’t have any Cisco or Extreme or Juniper
gear running IS-IS to verify myself…
On current Arista (7280SR2K) and older Brocade (MLXe) routers, the
IPv6 next-hop address in IS-IS seems to always be the link-local
address of the neighbour, instead of any manually-assigned address on
the interface. I believe this is **not** the case with Cisco, in
particular. Not sure about other vendors, I don’t have any handy that
can run IS-IS. I don’t appear to have any knobs to control this
behaviour, and haven’t found anything related in the docs.
Can anyone confirm that Cisco or other vendors does/do not do this
(prefer LLA over GUA)?
Junos:
2c0f:feb0::1/128 *[IS-IS/18] 02:43:49, metric 5870
to fe80::1205:caff:fe86:4ac3 via et-4/0/2.0
to fe80::5287:89ff:fef3:25c3 via et-4/0/2.0
to fe80::1205:caff:fe86:4b10 via et-5/0/2.0
> to fe80::5287:89ff:fef3:2610 via et-5/0/2.0
IOS XE:
I2 2C0F:FEB0::1/128 [115/6410]
via FE80::1205:CAFF:FE86:4AC3, TenGigabitEthernet1/0/0
via FE80::1205:CAFF:FE86:4B10, TenGigabitEthernet0/0/0
via FE80::5287:89FF:FEF3:25C3, TenGigabitEthernet1/0/0
via FE80::5287:89FF:FEF3:2610, TenGigabitEthernet0/0/0
IOS XR:
i L2 2c0f:feb0::1/128
[115/5870] via fe80::1205:caff:fe86:4b10, 02:45:22,
HundredGigE0/3/0/0 (!)
[115/5810] via fe80::f60f:1bff:feb0:75c4, 02:45:22,
HundredGigE0/2/0/1
Mark.
