One NIC with multiple IP addresses on different networks?

[Thomas Nikolajsen]

>ifconfig bge0 202.111.111.111 255.255.255.0
>ifconfig bge0 alias 202.111.111.112 255.255.255.255
>
>note they are on the same network.
>
>What if the alias was on a 203.xxx.xxx.xxx? Would that work? What would
>the netmask be in such case?

Whatever you like.

I.e. what your ip-addr plan says.
(I don't think we support /31 though)

(it is often noted that you should ask your network admin,
before using ip-addr / mask; to ensure it is consisten with ip-addr plan;
but I guess it is you)

Non-overlapping ip-subnets for interfaces is the normal case;
overlapping, which you mention, is the speciale case, that many ip devices doesn't support.

 -thomas