Hi,
with IOS the configuration looks like this:
router isis 1
advertise passive-only
passive-interface Loopback0
interface Loopback0
ip address 10.15.144.32 255.255.255.255
with this configuration is very clean and easy to get only the Loopbacks into isis - as I said with IOS.
Now I need to migrate this configuration into NXOS. There is a configuration option isis passive (passive-interface) but it does the complete oposite what I want to achieve:
"Prevents the interface from forming adjacencies but still advertises the prefix associated with the interface."
- I will have all my transfer networks in isis and it will prevent to form an isis adjacency.
I have tried several different ways with isis passive (passive-interface) for example:
router isis 1
passive-interface default level-2
interface port-channel1
ip address 10.15.144.140/31
ip router isis 1
isis metric 1 level-2
isis network point-to-point
interface Loopback0
ip address 10.15.144.32 255.255.255.255
no isis passive-interface level-2
I was not able to only get the Loopback (10.15.144.32/32) into isis. If there is a way without using route-map/prefix list I would like to know how.
I was also not able to solve my problem using route-map and prefix lists - here are some relevant show commands:
# sh ip route
IP Route Table for VRF "default"
'*' denotes best ucast next-hop
'**' denotes best mcast next-hop
'[x/y]' denotes [preference/metric]
'%<string>' in via output denotes VRF <string>
10.15.144.32/32, ubest/mbest: 2/0, attached
*via 10.15.144.32, Lo0, [0/0], 06:11:55, local
*via 10.15.144.32, Lo0, [0/0], 06:11:55, direct
10.15.144.140/31, ubest/mbest: 1/0, attached
*via 10.15.144.140, Po1, [0/0], 06:05:35, direct
10.15.144.140/32, ubest/mbest: 1/0, attached
*via 10.15.144.140, Po1, [0/0], 06:05:35, local
# sh isis route
IS-IS process: 1 VRF: default
IS-IS IPv4 routing table
10.15.144.140/31, L2, direct
*via port-channel1, metric 1, L2, direct
# sh route isis
route-map ISIS-DIRECT-ALLOW, permit, sequence 10
Match clauses:
ip address prefix-lists: ISIS-DIRECT-ALLOW-LOOPBACK
Set clauses:
route-map ISIS-DIRECT-ALLOW, permit, sequence 20
Match clauses:
ip address prefix-lists: DENY-ALL
Set clauses:
# sh isis redistribute route
IS-IS process: 1 VRF: default
IS-IS IPv4 redistribute route
10.15.144.32/32, direct,
Redistributed into L2, metric 10
# sh isis route-map statistics redistribute direct
IS-IS process: 1
VRF: default
C: No. of comparisions, M: No. of matches
route-map ISIS-DIRECT-ALLOW permit 10
match ip address prefix-list ISIS-DIRECT-ALLOW-LOOPBACK C: 3 M: 1
route-map ISIS-DIRECT-ALLOW permit 20
match ip address prefix-list DENY-ALL C: 2 M: 2
Total accept count for policy: 1
Total reject count for policy: 2
Here is the relevant configuration:
router isis 1
redistribute direct route-map ISIS-DIRECT-ALLOW
route-map ISIS-DIRECT-ALLOW permit 10
match ip address prefix-list ISIS-DIRECT-ALLOW-LOOPBACK
route-map ISIS-DIRECT-ALLOW permit 20
match ip address prefix-list DENY-ALL
ip prefix-list ISIS-DIRECT-ALLOW-LOOPBACK seq 10 permit 10.15.144.32/32
ip prefix-list DENY-ALL seq 10 deny 0.0.0.0/0 le 32
interface port-channel1
ip address 10.15.144.140/31
ip router isis 1
isis metric 1 level-2
isis network point-to-point
interface Loopback0
ip address 10.15.144.32 255.255.255.255
On all other connected isis routers I still see the Prefix from Port-Channel1 (10.15.144.140/31) in my isis and also routing table.
For me this looks like a bug, but I also tried with different NXOS versions and got the same results that's why I hope to find some helpful hints here.
thank you.
regards,
ulf
