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Cisco Bug: CSCvt62547 - ISIS holding a route even if nexthop tunnel-te is down

Last Modified

Jun 19, 2020

Products (1)

  • Cisco ASR 9000 Series Aggregation Services Routers

Known Affected Releases


Description (partial)

ISIS holding a route with nexthop as tunnel-te<xyz>. The tunnel-te<xyz> is down and ISIS still holds the route with nexthop as tunnel-te<xyz>. Hence, the route is seen in RIB as well. A correct route gets installed after ISIS process restart

R2---- R3 --- R1
R2 - headend, R3 midpoint, R1 tailend.

Issue Trigger Steps:
1.	Add ISIS interface TE0/1/0/1.102 on R3 in wrong ISIS instance core,
2.	Check for isis database having tail-end router-id ( from 2 ISIS LSP IDs one of instance core & other of ISIS_PREAGG,
3.	Remove wrongly added isis interface TE0/1/0/1.102 from ISIS core,
4.	Delete ISIS instance ISIS_PREAGG config from midpoint R3 & tail-end R1,
5.	Reload tail-end R1.
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