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Cisco Bug: CSCul87230 - CRS. Route output show bad routing entry

Last Modified

Nov 22, 2018

Products (1)

  • Cisco Carrier Routing System

Known Affected Releases

4.0.3.BASE

Description (partial)

Symptom:
Platform: CRS-8/S
S/W: 4.0.3
Problem: 
CU has identified a strange behavior on one CRS. When they insert a zero on the third octet on a prefix, “show ip route” output  matches to a different routing entry, but cef is correct

#sh ip route 195.xxx.xx.139
Wed Oct 30 12:30:46.239 CET
Routing entry for 195.xxx.xx.128/25
  Known via "bgp 64530", distance 20, metric 100
  Tag 65093, type external
  Installed Oct 29 01:00:59.838 for 1d11h
  Routing Descriptor Blocks
    81.xx.xx.14, from 81.xx.xx.14

      Route metric is 100
  No advertising protos. 

#sh ip route 195.xxx.xxx.139
Wed Oct 30 12:30:51.909 CET

Routing entry for 195.xxx.xx.0/24
  Known via "bgp 64530", distance 200, metric 100
  Tag 64961, type internal
  Installed Jul 31 15:21:48.032 for 12w6d
  Routing Descriptor Blocks
    194.xx.xxx.48, from 80.xx.xx.128
      Route metric is 100
  No advertising protos.

#sh cef 195.xx.xx.139
Wed Oct 30 12:32:07.272 CET
195.xxx.xx.128/25, version 33, internal 0x40000001 (ptr 0x9f38fe7c) [1], 0x0 (0x0), 0x0 (0x0)
 Updated Oct 29 01:00:59.872
 Prefix Len 25, traffic index 0, precedence routine (0)
 BGP Attribute: id: 0x3596, Local id: 0x3666, Origin AS: 65093, Next Hop AS: 65093 
 
   via 81.xx.xx.14, 3 dependencies, recursive, bgp-ext [flags 0x20]
    path-idx 0
    next hop 81.xx.xx.14 via 81.xx.xx.14/32

RP/0/RP0/CPU0:rrcmde5-61#sh cef 195.xxx.xxx.139

Wed Oct 30 12:32:16.384 CET
195.xxx.xx.128/25, version 33, internal 0x40000001 (ptr 0x9f38fe7c) [1], 0x0 (0x0), 0x0 (0x0)
 Updated Oct 29 01:00:59.872
 Prefix Len 25, traffic index 0, precedence routine (0)
 BGP Attribute: id: 0x3596, Local id: 0x3666, Origin AS: 65093, Next Hop AS: 65093 
 
   via 81.xx.xx.14, 3 dependencies, recursive, bgp-ext [flags 0x20]
    path-idx 0
    next hop 81.xx.xx.14 via 81.xx.xx.14/32

Conditions:
identified a strange behavior on one CRS. When they insert a zero on the third octet on a prefix, "show ip route"€ output matches to a different routing entry, but cef is correct.
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