[Xorp-users] Emulating multiple routers on the same host

[Ratul Mahajan]

 > You can currently run multiple BGP instances on the same machine, as
 > BGP uses TCP, and you can configure the peer address and port on a
 > per-peer basis.  So if you want to experiment with BGP, this is
 > possible without code changes.  But the resulting virtual routers
 > won't actually forward packets to each other, so this is only useful
 > for routing experiments, not a general solution.

so whats the simplest way to accomplish this?

thanks!

ps: i realize that the answer is there somewhere in the code/docs but it 
would help to have specific pointers.

Mark Handley wrote:
>>The XORP Vision page mentions the ability to emulate multiple routers on 
>>the same host, saying this can be done if you modify the FEA.  My 
>>question is how do you modify the FEA to do this?  Do you have to hack 
>>code, or can this be done by configuration?
> 
> 
> Right now you'd have to hack code for it to be general.  You could run
> multiple dummy FEA processes (each with its own finder and routing
> protocols) but there would be no way to exchange routing packets
> between the different virtual routers.  
> 
> As part of a project to implement IS-IS in XORP, I have a student who
> is looking to test his implementation by emulating multiple routers,
> so we've given some thought to how to make this work (but he was only
> looking at IS-IS).  But right now, there's no code committed into CVS
> to do this.
> 
> You can currently run multiple BGP instances on the same machine, as
> BGP uses TCP, and you can configure the peer address and port on a
> per-peer basis.  So if you want to experiment with BGP, this is
> possible without code changes.  But the resulting virtual routers
> won't actually forward packets to each other, so this is only useful
> for routing experiments, not a general solution.
> 
>  - Mark