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From: Brian Litzinger <brian@MediaCity.com>
Message-Id: <199604300944.CAA06515@MediaCity.com>
Subject: Re: IP aliases and delays
To: angio@aros.net (Dave Andersen)
Date: Tue, 30 Apr 1996 02:44:08 -0700 (PDT)
Cc: freebsd-questions@FreeBSD.org
In-Reply-To: <199604300641.AAA26399@terra.aros.net> from Dave Andersen at "Apr 30, 96 00:41:22 am"
Reply-To: brian@MediaCity.com
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Dave Andersen wrote:
> > Why bother?  FreeBSD allows you to alias an arbitrary number of addresses
> > to an interface, so dummy interfaces are completely unnecessary.
> 
>   On the stupid question front, I'm wondering if anyone's actually looked 
> at the kind of degredation you get with packet response times on aliased 
> interfaces?
>   
>   To wit:  On a linux 1.2.13 with aliasing, the 130th alias takes ~3ms 
> longer to ping on a local ethernet than the interface address itself.  
> (4.5ms vs 1.5ms).  I don't have enough aliases on the freebsd boxes to 
> test this (and they're 'production' so I'm not in the mood to play with 
> them. :), so I'm curious if someone's actually looked at it?

              ping
True Ip:      1.592ms
157th alias:  2.556ms

Machine is an P5-75 with DEC 21040 ethernet interface.

Brian Litzinger
brian@mediacity.com