23 Mar

Missess counters on Cisco routers

According to Cisco’s documentation misses represents “number of times the software performs a translation table lookup and fails to find an entry, and creates one“. So all routers should have some misses in their counters. Let’s look at some 1841 router statistics:

C1841#sh ip nat statistics 
Total active translations: 3339 (0 static, 3339 dynamic; 3339 extended)
Peak translations: 8114, occurred 18:35:17 ago
Outside interfaces:
  FastEthernet0/0
Inside interfaces: 
  FastEthernet0/1
Hits: 28658670  Misses: 0

No misses, only hits that increases every time “the software performs a translation table lookup and finds an entry“. It works same on every ISR and 7200 routers. But still documentation says otherwise.
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