[mpls-linux-general] Re: MPLS-Linux

[James R. L. <jl...@mi...>]

On Sat, Jun 23, 2001 at 04:12:33AM +0500, Saeed Akhter wrote:
> Hi Everybody,
> 
> Can anybody just verify (or correct my configuration,if I am wrong)for 
> following scenerio;(LER A and LER B are simulated Routers)
> 
> 
> LER A-----------------LSR 1-----------LSR 2---------LER B
> 192.168.100.3       eth1   eth2    eth0   eth1       192.168.200.3
> 
> 
> LSR 1 eth1...192.168.100.1
> LSR 1 eth2...192.168.101.1
> 
> LSR 2 eth0...192.168.101.2
> LSR 2 eth1...192.168.200.1
> 
> I configured LSR 1 as under;
> 
> mplsadm -v -L eth1:0
> mplsadm -v -L eth2:0
> 
> mplsadm -A -B -I gen:16:0 -O gen:26:eth2:ipv4:192.168.101.2 -f 
> 192.168.200.3/32

In this senerio you do not need the -f option.  In fact mplsadm may do the
wrong thing right now

The above command line should do the following (although as I said above,
mplsadm may have a bug which prevents all of these from happening):

-create in label gen:16:0
-create out label gen:26:eth2:ipv4:192.168.101.2
-bind the in label to the out label
-bind the fec (192.168.200.3/32 to the out label)

> (I believe above command will swap the label 16 with 26 and will send-out 
> the label 26 to 192.168.200.3 through LSR 2)
> 
> I configured LSR 2 as under;
> 
> mplsadm -v -L eth0:0
> mplsadm -v -L eth1:0
> 
> mplsadm -A -B -I gen:26:0 -O gen:27:eth1:ipv4:192.168.200.3

This command line looks right.

Couple of things to note:

-This only establishes an LSP for traffic from LER A to LER B.  Traffic
 from LER B to LER A will try to go via normal routing (unless you setup
 another LSP)
-Label spaces are only required on the incoming interfaces (not on the
 interface specified in the out label) It doesn't break anything to specify
 a label space on the outgoing interferface, it is just unnecessary.

Make sure to double check you work by looking at the files /proc/net/mpls_*
to make sure the kernel has done what you told it to.

Jim
-- 
James R. Leu