[c-nsp] Re-thinking (remembering) how a switch operates

Niels Bakker niels=cisco-nsp at bakker.net
Fri May 6 18:34:54 EDT 2005


* gert at greenie.muc.de (Gert Doering) [Thu 05 May 2005, 09:24 CEST]:
>On Wed, May 04, 2005 at 06:35:06PM +0200, Andre Beck wrote:
>>End stations of today usually have ARP cache timeouts of 120s to 300s.
>At least Linux is doing IPv4 ARP timeouting these days similar to way 
>IPv6 NUD works - "if we see no traffic from this IP/MAC combination for 
>a while, we do some ARP probing.  Otherwise we assume that it's still 
>valid" - which is a good thing in large networks, avoiding unnecessary 
>ARPs...

Except they do that after 30 seconds, which makes Linux boxes generate 
insane amounts of ARP traffic compared to any other host.


	-- Niels.

-- 


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