configuring two network interfaces, same subnet

Alfredo Aguirre aguirre at
Mon Jun 13 19:07:40 GMT 2005

Hello people!,

I'm trying to configure 2 network interfaces in the same subnet, because i
want to  use one interface for NS and the other for MX,

if i try
bash-2.05b# ifconfig em0 netmask
bash-2.05b# ifconfig em1 netmask
ifconfig: ioctl (SIOCAIFADDR): File exists

ok they both cannot be in the same subnet.

i know that i cannot have them both in the same subnet without modifying
the routing, but im confussed about it.

i also tried after settin' one of the ips, deleting the routing

bash-2.05b# route delete

and then setting the ip

bash-2.05b# ifconfig em0 netmask 255.255.255.

ok i can now set the 2 ips in the same subnet but my DNS stops working,

i dont want to change the submask, for any of my ips

well im confused about it, so i hope you guys could adress me in the right

Thanks in advance,


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