Isis neighbors are not in the down state

[Yvan.hua]

I use oid 1.3.6.1.4.1.9.10.118.1.6.1.1.2 to capture Isis neighbor status. 3 is up and 1 is down.

When there is a problem with the link, for example, the interface is closed, the Isis neighbor disappears, and there is no real down. Why?

R4#show isis neighbors

Tag null:
System Id Type Interface IP Address State Holdtime Circuit Id
R1 L2 Gi0/0/0 14.1.1.1 UP 26 01
R2 L2 Gi0/0/2 24.1.1.2 UP 21 03
R5 L2 Gi0/0/1 45.1.1.5 UP 26 02
R4#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R4(config)#int g0/0/0
R4(config-if)#sh
R4(config-if)#shutdown
R4(config-if)#do show isis
*Aug 17 05:28:11.157: %LINK-5-CHANGED: Interface GigabitEthernet0/0/0, changed state to administratively down
*Aug 17 05:28:12.158: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0/0, changed state to down
R4(config-if)#do show isis nei

Tag null:
System Id Type Interface IP Address State Holdtime Circuit Id
R2 L2 Gi0/0/2 24.1.1.2 UP 27 03

R5 L2 Gi0/0/1 45.1.1.5 UP 23 02

[balaji.bandi]

what device is this ? and what IOS code running ?

[Yvan.hua]

IOS is IOS-XE, and the device is Cisco 4000 series

[balaji.bandi]

ok to get clarity - is the results not appearing when the ISIS down in SNMP walk ?

can you share the results before and after (ISIS up and down)

[Yvan.hua]

up:

[root@localhost ~]# snmpwalk -v 2c -O n -c ***** "ip"  1.3.6.1.4.1.9.10.118.1.6.1.1.2
.1.3.6.1.4.1.9.10.118.1.6.1.1.2.12.1 = INTEGER: 3
.1.3.6.1.4.1.9.10.118.1.6.1.1.2.19.2 = INTEGER: 3

down:

[root@localhost ~]# snmpwalk -v 2c -O n -c ******  *****(ip) 1.3.6.1.4.1.9.10.118.1.6.1.1.2
.1.3.6.1.4.1.9.10.118.1.6.1.1.2.12.1 = INTEGER: 3

Whether you use SNMP walk or show Isis Nei on the router, the neighbor entry disappears.

[Yvan.hua]

The result equal to 3 represents up and the result equal to 1 represents down. However, when the link fails and the Isis neighbor goes down, the entry disappears.

[Georg Pauwen]

Hello,

not really sure what you are asking. You are polling the ISIS adjacency, not the interface status. What is the result of the polling when you shut the interface ?

[Yvan.hua]

For example:

One Cisco router and one juniper router are configured with isis protocol

When the link is normal, juniper and Cisco routers will display "up"

When the link is interrupted, juniper router will display "down", and Cisco router cannot see this entry.

I hope to see "down" on the Cisco router. I need to use this status as an alarm