[c-nsp] EoMPLS with Port-channel with 8GE interfaces.

[Alexandre Snarskii]

On Mon, Aug 25, 2008 at 04:07:48PM +0200, Oliver Boehmer (oboehmer) wrote:
> Maarten Moerman <> wrote on Monday, August 25, 2008 3:54 PM:
> 
> > Hi,
> > 
> > I have a kind of problem at the moment which I'll try to explain here.
> > 
> > Diagram:
> > 
> >  sw1 with 4 * GE--> 4 * GE @ r1 @ 10GE--> 10GE @ r2 4 * GE--> 4 *
> > GEsw2 
> > 
> > sw1 + sw2 = 6509 with 6748 blades
> > r1 + r2 = 7604 with 6748 blades, and their interconnects are on 10GE
> > xenpaks on 6704 10GE blades
> > 
> > On sw1 +2 I have:
> > 
> > Int port-channel1
> > Trunk encaps dot1q (multiple vlan)
> > 
> > Int giga x/1-4
> > Channel-group 1 mode on
> > 
> > On r1 + r2 I have:
> > 
> > Int port-channel 1
> >  mtu 9216
> >  xconnect <loopback IP other router> <mpls-tag> encapsulation mpls
> > 
> > Int giga x/1-4
> >  mtu 9216
> >  channel-group 1 mode on
> > 
> > However, I'm currently facing the problem, that I cannot exceed the
> > bandwith of that port-channel over 1gbit. The ingress is no problem,
> > it tries to send, but the other side doesn't seem to pick up the
> > traffic. 

Looks like you see the same problem as me: 
http://puck.nether.net/pipermail/cisco-nsp/2007-March/039451.html

We solved this issue with avoiding eompls and transferring
data over 10ge-link as simple switched vlan. 

Another (possible) solution - you can do some xconnect's from 
one sw to another (they're 6509, right ? So, you can load SRA
or SXH IOS on them and do xconnects directly between switches). 
Why that solution not guaranteed to work - if you have to xconnect
vlan with more than one gbit of traffic, you'll face the same 
problem not on rt egress, but on egress of the first sw. 


> > Does this have to do with the fact that the portchannel on the
> > routers only see 1 source, and 1 destination address? So that it
> > cannot correctly balance traffic among 4 interfaces?
> > 
> > Anybody has an idea how to solve this?
> 
> I've never done xconnect on a port-channel, but you could remove the
> channel on r1 and r2 and just configure "regular" EoMPLS PWs between
> each of the four GigE links. Channeling is then only performed on sw1
> and sw2.. I would consider running LACP/PaGP on the channel between
> sw1/sw2..
> This should work.

Well, it should, but not in case when you need to xconnect only 
some vlan's from portchannel, and others you need to terminate
locally or xconnect to another destinations...

-- 
Alexandre Snarskii

If you ask a stupid question, you may feel stupid. 
If you don't ask a stupid question, you remain stupid.
                                       -Tony Rothman, Ph.D.U. Chicago, Physics