NAT - Expired translations, Hits and misses - HOW SOLVED

leandro.candido · ‎03-19-2008

Dear all,

I need of your help.

I have a route 1841 (12.3(8r)T9)with nat protocol configured.

Sometimes the address translaioned (source) loss de connection with the destinantion address. Then I access the router and clear the nat table and the connection returns.

I see some outputs on command show ip nat translations como: hits, misses and expired translations.

Nat#sh ip nat sta

Total active translations: 162 (1 static, 161 dynamic; 104 extended)

Outside interfaces:

FastEthernet0/1

Inside interfaces:

FastEthernet0/0

Hits: 3455261 Misses: 17583

CEF Translated packets: 3398678, CEF Punted packets: 147939

Expired translations: 19776

Dynamic mappings:

-- Inside Source

[Id: 1] access-list 2 pool Panamericano refcount 161

pool Palmeiras: netmask 255.255.255.0

start X.X.X.X end X.X.X.X

type generic, total addresses 127, allocated 57 (44%), misses 0

Queued Packets: 0

How can i to do solved this case?

Thanks

Leandro

amritpatek · ‎03-25-2008

Nat misses are normal in nat operation. Nat misses mean the number of times the software does a translations table lookup, fails to find an entry, and must try to create one. The 'pool misses' counter indicates number of address allocation failures and this should be checked for troubleshooting.