"subinterfaces" is no cisco speak for aliases. The Cisco speak for aliases is "secondary" In Cisco terms you can add an alias to an interface by typing: ip address <address> <mask> secondary. Even a third address can be added with this statement.
The subinterface concept is mainly used for running IP over frame relay networks.
You can have an interface to a frame relay network, with multiple subinterfaces for connecting to multiple hosts on the same frame relay network.
This has to do with the NBMA (non-broadcast multiple access) nature of frame relay. This basically means that basic ARP does not work on frame relay. And this is the reason why subinterfaces are really useful on these networks.
But I do not fully know this matter in Cisco, nor in Linux speak.
More information on the Cisco concept of subinterfaces can be found at: http://www.cisco.com/warp/public/779/smbiz/service/knowledge/wan/subifs.htm
I guess John wants to know the capabilities of Linux concerning frame relay, but I don't know anyone with experience on this is on the list.
The linux equivalent for subinterfaces depends on what you want to do with it, I guess.
bert hubert wrote:
On Wed, Jan 17, 2001 at 09:32:01PM -0500, John Russo wrote:
Does Linux support the concept of subinterfaces? If so can anyone point me in the right direction for docs?
I think 'subinterfaces' are Cisco speak for IP aliases - if so, yes, try this:
ip addr add your.ip.address.here dev eth0
