[ILUG] 3 IP's one machine?

[Colm Buckley]

Donncha writes:

> This is what I did to get two IPs on one interface. There's a mini howto
> on the subject (IP_Alias I think)
> 
> /sbin/ifconfig eth0:0 192.168.0.35
> /sbin/route add -host 192.168.0.35  dev eth0:0

Under kernel 2.2, you don't need to explicitly add routes to a
particular host/net; it automatically binds each interface to its
subnet, unless you specify multiple interfaces on the same subnet, in
which case the first is the default route to that subnet.

Eg:  if I do "ifconfig eth0 192.168.1.1 netmask 255.255.255.0",  and
"ifconfig eth0:0 10.0.22.5 netmask 255.0.0.0" then I
automatically get a route to 192.168.1.0/24 through eth0, and one to
10.0.0.0/8 through eth0:0

It's a good idea, in these days of classless delegation, to always
explicitly add a netmask to your ifconfig commands, the defaults may not
be correct, and you end up with bad routes and broadcast addresses.

           Colm

-- 
Colm Buckley BA BF | NewWorld Commerce, 44 Westland Row, Dublin 2, Ireland
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