Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 21 May 1999 08:14:41 -0700
From:      Graeme Tait <graeme@echidna.com>
To:        Aaron Gifford <agifford@infowest.com>
Cc:        freebsd-isp@freebsd.org
Subject:   Re: ifconfig_if0_alias?
Message-ID:  <37457861.278E@echidna.com>
References:  <19990521043504.2D45915316@hub.freebsd.org>

next in thread | previous in thread | raw e-mail | index | archive | help
Aaron Gifford wrote:

<snip>

> Just to be sure I wasn't wasting my time adding static loopback
> routes for every IP alias, I did a quick ping test:
> 
> PINGing a local IP alias that does NOT have a loopback route:
> 
> --- 10.200.55.242 ping statistics ---
> 1000 packets transmitted, 1000 packets received, 0% packet loss
> round-trip min/avg/max/stddev = 0.119/0.136/0.217/0.015 ms
> 
> PINGing a local IP alias that DOES have a loopback route:
> 
> --- 10.200.55.243 ping statistics ---
> 1000 packets transmitted, 1000 packets received, 0% packet loss
> round-trip min/avg/max/stddev = 0.093/0.106/0.305/0.015 ms
> 
> It looks like the loopback route shaves off .030 ms on average
> at least in this case processing pings.


I created some IP aliases per http://www.cypher.net/~black/ipalias.html

ifconfig fxp0 inet xxx.xxx.xxx.100 netmask 255.255.255.255 alias
ifconfig fxp0 inet xxx.xxx.xxx.101 netmask 255.255.255.255 alias

Explicitly adding routes (which the above reference says is unnecessary 
with netmask 255.255.255.255) with

route add xxx.xxx.xxx.100 127.0.0.1
route add xxx.xxx.xxx.101 127.0.0.1

made no difference whatever to the ping times to those IP's on the local 
system (2.2.7S/CAM), which was otherwise idle.


Does adding a loopback route for your .242 IP reduce its ping time? Was 
your system under load, and the load consistent?


-- 
Graeme Tait - Echidna



To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-isp" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?37457861.278E>