2

I need to confirm the below as i don't have access to a lab.

I have 4 XR boxes connected linearly as shown.Router A is advertsing PC subnet in isis. My understanding: So when the subnet of PC A reaches the Router D, the overall metric should be as

Cost of PC A to Router A link + 16777214(A-B link cost) + 16777214(B-C link cost) +16777214 (C-D link cost) But the max metric in isis is 16777214, so will the final route get installed or not? If so, with what metric?

With what metric will Router D learn the subnet of PC connected to Router A?

enter image description here

2

I just labbed it in VIRL. For the PC subnet, I get a metric of 50331642 on Router D:

Routing entry for 10.0.0.4/30
  Known via "isis 1", distance 115, metric 50331642, type level-2
  Installed Feb 28 17:46:19.166 for 00:00:07
  Routing Descriptor Blocks
    10.0.0.17, from 192.168.0.2, via GigabitEthernet0/0/0/0
      Route metric is 50331642
  No advertising protos. 

Note that I had to manually set the IS-IS link metric to 16777214 on all applicable interfaces under the ISIS config. Otherwise it defaults to a link metric of 10 for a total metric of 30 on Router D.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.