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New Member

Nat tunning


In my router, the nat increase the use of cpu. I don't know if the tuning of nat can help us to decrease it. If yes, how can i configure nat tuning ?



Re: Nat tunning

What release of IOS are you using. NAT should not really be that taxing on the router.

IMO Release 12.3 and higher support translation type supports which would lead to more optimized nat translation tables.


New Member

Re: Nat tunning

Globalnet_sat3#sh version

Cisco IOS Software, 2801 Software (C2801-IPBASE-M), Version 12.3(8)T4, RELEASE S


Technical Support:

Copyright (c) 1986-2004 by Cisco Systems, Inc.

Compiled Fri 03-Sep-04 00:01 by eaarmas

ROM: System Bootstrap, Version 12.3(8r)T8, RELEASE SOFTWARE (fc1)

Globalnet_sat3 uptime is 1 week, 3 days, 17 hours, 20 minutes

System returned to ROM by bus error at PC 0x60C2001C, address 0x136D4 at 19:37:3

3 UTC Mon Feb 20 2006

System image file is "flash:c2801-ipbase-mz.123-8.T4.bin"

cisco 2801 (revision 4.1) with 118784K/12288K bytes of memory.

Processor board ID FHK084010J9

2 FastEthernet interfaces

2 Serial interfaces

2 Channelized E1/PRI ports

DRAM configuration is 64 bits wide with parity disabled.

191K bytes of NVRAM.

62592K bytes of ATA CompactFlash (Read/Write)

please, how can i optimise nat ??



Re: Nat tunning

You already seem to have IOS 12.3 so upgrading it further may not lead to substantial improvements.

By optimizing NAT what exactly do you mean ? If youre looking at a whole load of traffic hitting the router at once, you might wanna take a shot at recommending a router upgrade or just upgrading the speeds of the interface if youre talking about speeds at which NAT happens... this is very subjective and can be justified only by constantly high processor loads. Im gonna have to ask you for more details on what your configuration looks like and what part of it are you looking to optimize?

New Member

Re: Nat tunning

I configure nat overload, with about 1.5M of traffic

traffic coming from translation.And about 4M for global traffic.


New Member

Re: Nat tunning

i can resolve it with nat tuning. with " ip nat translation icmp-timeout , ip nat translation tcp-timeout, ip nat translation udp-timeout, etc.. "

Any suggest will be appreciated.


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