Subject: Re: inet aliases and routed
To: Andrew Gillham <>
From: Andrew Brown <>
List: current-users
Date: 08/16/2000 23:24:12
>You need a route via the loopback to make this work.  This should be
>added automatically if you use /etc/ifaliases.  I believe 'ifconfig' adds
>this automatically when you add the "primary" address.
>(e.g. my machine has a route via loopback for it's primary ethernet's
>ip address)
>'route add $alias'

i looked at that, too, but saw the same sort of comment.

        # Note that /etc/ifaliases works only with certain cases only and its
        # use is not recommended.  Use /etc/ifconfig.xxN instead.

so i went with the ifconfig.xxN solution.

can someone describe the "certain cases" bit?  i argued with karels at
one point about the benefits/drawbacks of assigning aliases to
physical interfaces vs. loopback interfaces (although with the new
interface cloning code, shouldn't i be able to create more loopback
interfaces for all my aliases?) and it seemed it was basically a case
of physical interface plus route add vs. loopback interface plus arp
stuffing and advertisement.

it seems to me that (a) the "route add" should be done for aliases as
well in the ifconfig.xxN case (although i realize that this is
probably non-trivial) and (b) it doesn't address my routed issue at
all.  :-/

|-----< "CODE WARRIOR" >-----|             * "ah!  i see you have the internet (Andrew Brown)                that goes *ping*!"       * "information is power -- share the wealth."