LARTC - Jan 2001 - subinterfaces

Does Linux support the concept of subinterfaces?  If so can anyone point
me in the right direction for docs?

Thank you,

John

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

-- 
PowerDNS                     Versatile DNS Services  
Trilab                       The Technology People   
''SYN! .. SYN|ACK! .. ACK!'' - the mating call of the internet

Both subinterfaces and secondairy interfaces are configurable on a Cisco router.
A
secondary interface is usualy used we you use up all you ip addresses in an
assigned subnet and you ned more addresses. On the other had subinterfaces are
used
to create logical interfaces, are usualy used to get around the split horizin
problem and frame relay or atm networks. Basicaly secondairy address meens one
interface with multible addresses, and subinterfaces meen multiple ilogical
interfaces.

Guy Van Den Bergh wrote:
> "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
>
> _______________________________________________
> LARTC mailing list / LARTC@mailman.ds9a.nl
> http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO:
http://ds9a.nl/2.4Routing/

"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