IP aliasing

[Terry Polzin]

On Wednesday December 13 2006 16:40, Rick Stevens wrote:
> On Wed, 2006-12-13 at 13:17 -0800, Mike Wright wrote:
> > Terry Polzin wrote:
> > > Does anyone still use this?
> > > Is it compiled into the default kernel?
> >
> > It is very easy to add address(es) to an interface.  From the command
> > line you could use the "ip" command to manipulate network devices.  You
> > can also add routes and bring devices up and down, change their MAC, and
> > many other fun things.
> >
> > ip addr add 1.2.3.4/24 dev eth5
> > ip addr add 2.3.4.5/16 dev eth5
> > ip addr add 3.4.5.6/8 dev eth5
> >
> > You would now have 3 addresses on different width subnets on one network
> > device.
> >
> > Its man page is very terse but gives a very good idea of its power.
>
> You can also create /etc/sysconfig/network-script/ifcfg-ethX:n
> files to add aliases.  Set them up like the original ifcfg-ethX
> file, just change the "DEVICE", "IPADDR" and "NETMASK" stuff as
> appropriate.  You don't want any "HWADDR" or "GATEWAY" entries in
> the aliases.  Examples:
>
> /etc/sysconfig/network-scripts/ifcfg-eth0:
> DEVICE=eth0
> BOOTPROTO=static
> HWADDR=ZZ:YY:XX:WW:VV:UU
> IPADDR=aaa.bbb.ccc.ddd
> IPV6ADDR=
> IPV6PREFIX=
> NETMASK=255.255.255.0
> ONBOOT=yes
>
> /etc/sysconfig/network-scripts/ifcfg-eth0:0
> DEVICE=eth0:0
> BOOTPROTO=static
> IPADDR=eee.fff.ggg.hhh
> IPV6ADDR=
> IPV6PREFIX=
> NETMASK=255.255.255.0
> ONBOOT=yes
Thanks for all the replies, last time I did this was with a 2.2 kernel, so 
it's been a while.