I'm wondering the causes of seeing a system ID instead of a hostname when issuing the command show isis neighbors. For instance:
IS-IS amen neighbors:
System Id Interface SNPA State Holdtime Type IETF-NSF
1041.0252.0042 Gi0/0/0/1 *PtoP* Up 27 L2 Capable
R5 Gi0/0/0/3 *PtoP* Up 25 L2 Capable
R6 Gi0/0/0/5 *PtoP* Up 28 L2 Capable
As you can see, I'm getting the system ID for a neighbor instead of its hostname. I'm not sure if this actually creates an issue, but it leads to another issue I'm seeing. I'm assuming they are related, but maybe they aren't.
The other issue I'm having is I've got 2 sites connected together via a transport link. One site is able to see all of the devices in the topology with show isis topology. However, the other site cannot. This other site is also not receiving its default route via ISIS like it should.
Here's a diagram of what I have.
Below is some config.
R1 ! interface Loopback0 ip address 10.41.252.42 255.255.255.255 ip router isis 100 ! interface GigabitEthernet0/1/3 switchport access vlan 67 ! interface GigabitEthernet0/1/5 switchport access vlan 66 ! interface GigabitEthernet0/1/7 switchport access vlan 7 ! interface Vlan7 ip address 10.41.65.42 255.255.255.0 ip router isis 100 isis circuit-type level-2-only isis network point-to-point ! interface Vlan66 ip address 10.41.66.42 255.255.255.0 ip router isis 100 isis circuit-type level-2-only ! interface Vlan67 ip address 10.41.67.42 255.255.255.0 ip router isis 100 isis circuit-type level-2-only ! ! router isis 100 net 49.0042.1041.0252.0042.00 R2 interface Loopback0 ipv4 address 10.41.252.201 255.255.255.255 ! interface GigabitEthernet0/0/0/1 ipv4 address 10.41.65.201 255.255.255.0 ! interface GigabitEthernet0/0/0/3 ipv4 address 10.41.69.201 255.255.255.0 ! interface GigabitEthernet0/0/0/5 ipv4 address 10.41.70.201 255.255.255.0 ! router isis 100 is-type level-2-only net 49.0200.0100.4125.2201.00 interface Loopback0 address-family ipv4 unicast ! ! interface GigabitEthernet0/0/0/1 circuit-type level-2-only point-to-point address-family ipv4 unicast ! ! interface GigabitEthernet0/0/0/3 address-family ipv4 unicast ! ! interface GigabitEthernet0/0/0/5 address-family ipv4 unicast ! ! ! R3 ! interface Loopback0 ipv4 address 10.41.252.2 255.255.255.255 ! interface GigabitEthernet0/0/0/0 ipv4 address 10.41.67.2 255.255.255.0 ! router isis 100 net 49.0002.1041.0252.0002.00 interface Loopback0 address-family ipv4 unicast ! ! interface GigabitEthernet0/0/0/0 circuit-type level-2-only address-family ipv4 unicast ! ! ! R5 interface Loopback0 ipv4 address 10.41.252.202 255.255.255.255 ! interface GigabitEthernet0/0/0/3 ipv4 address 10.41.69.202 255.255.255.0 router isis 100 is-type level-2-only net 49.0200.0100.4125.2202.00 interface Loopback0 address-family ipv4 unicast ! ! interface GigabitEthernet0/0/0/3 address-family ipv4 unicast ! ! !
Below are some commands where I'm not seeing what I would expect to see.
RP/0/RP0/CPU0:R2#sh isis neigh Mon Sep 24 13:22:06.969 EDT IS-IS amen neighbors: System Id Interface SNPA State Holdtime Type IETF-NSF 1041.0252.0042 Gi0/0/0/1 *PtoP* Up 25 L2 Capable R5 Gi0/0/0/3 008a.962f.3c0c Up 27 L2 Capable R6 Gi0/0/0/5 6cb2.aeb0.aa80 Up 8 L2 Capable Total neighbor count: 3 RP/0/RP0/CPU0:R2#sh isis topology Mon Sep 24 13:23:58.470 EDT IS-IS amen paths to IPv4 Unicast (Level-2) routers System Id Metric Next-Hop Interface SNPA R2 -- R5 10 R5 Gi0/0/0/3 008a.962f.3c0c R6 10 R6 Gi0/0/0/5 6cb2.aeb0.aa80 RP/0/RP0/CPU0:R2#sh ip route Mon Sep 24 13:26:39.108 EDT Gateway of last resort is not set C 10.41.65.0/24 is directly connected, 5d01h, GigabitEthernet0/0/0/1 L 10.41.65.201/32 is directly connected, 5d01h, GigabitEthernet0/0/0/1 C 10.41.69.0/24 is directly connected, 5d03h, GigabitEthernet0/0/0/3 L 10.41.69.201/32 is directly connected, 5d03h, GigabitEthernet0/0/0/3 C 10.41.70.0/24 is directly connected, 5d01h, GigabitEthernet0/0/0/5 L 10.41.70.201/32 is directly connected, 5d01h, GigabitEthernet0/0/0/5 L 10.41.252.201/32 is directly connected, 5d00h, Loopback0 i L2 10.41.252.202/32 [115/20] via 10.41.69.202, 00:09:16, GigabitEthernet0/0/0/3 i L2 10.41.252.203/32 [115/20] via 10.41.70.203, 00:07:53, GigabitEthernet0/0/0/5
As you can see on R2, it's not learning R3 or R4. However, R3 and R4 are learning everything about site B. On R2, I'm also not receiving a default route from R1 like I should be. However, R3 and R4 are learning a default route.
