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[QFX] Some IPV6 Routes in the ISIS database does not show up in the routing table



Article ID: KB35573 KB Last Updated: 14 Mar 2020Version: 2.0

This article describes a scenario where some IPV6 routes that are not in the routing table appear in the ISIS database.




QFX-A has the IPv6 prefix '2a01:75e0:e000:4::/128' in the ISIS database, but this prefix is not in the route table.

root@QFX-A> show isis database extensive iad6-dc01 | match 2a01:75e0:e000:4::/128 

 V6 prefix: 2a01:75e0:e000:4::/128 Metric: 0 Internal Up 
 IPv6 prefix: 2a01:75e0:e000:4::/128 Metric 0 Up 
root@QFX10008-A> show route 2a01:75e0:e000:4:: 

 inet6.0: 482 destinations, 644 routes (267 active, 0 holddown, 377 hidden) 

 + = Active Route, - = Last Active, * = Both 

 ::/0 *[Static/5] 01:38:26, metric2 1000 

 > to fe80::bac2:53ff:fe64:965b via ae24.0 

 inet6.3: 17 destinations, 17 routes (17 active, 0 holddown, 0 hidden) 

 + = Active Route, - = Last Active, * = Both 

This issue occurred because QFX-B did not configure IPv6 address on the interface, which caused QFX-A to not have IPv6 neighbor for the prefix's next hop.


Configure family inet6 address for QFX-B's interface ae22. Make sure both sides have the IPv6 neighbor for each other.

Command to configure the IPv6 address:

set interface ae22 unit 0 family inet6 address <address/mask>


set interface ae22 unit 0 family inet6 address 2a01:75e0:e000:4::1/126
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