[j-nsp] loop detection on EX4200

[Victor Sudakov]

Chuck Anderson wrote:
> On Mon, Apr 21, 2014 at 03:20:42PM +0700, Victor Sudakov wrote:
> > Dave Bell wrote:
> > > You could try enabling bpdu-block-on-edge.
> > > 
> > > http://www.juniper.net/techpubs/en_US/junos12.2/topics/task/configuration/spanning-trees-bpdu-block-cli.html
> > 
> > This is not an edge interface, I need RSTP running on it.
> 
> Did the multiplexer not loop back RSTP BPDUs?

Thank you for mentioning this. It's a new outlook on the problem. Now
that I think of it, it probably did not.

I suspect that the multiplexer does not let (some) untagged frames
through.  That means Juniper's RSTP would not work through it (though
Cisco's PVST does because it uses tagged frames). That means I should
expect more serious problems with the multiplexer than an occasional
physical loop.

> 
> You could enable mac-limit if the number of incoming learned MAC
> addresses is expected to be lower than the number of outgoing source
> MAC addresses.

I should think this over. I don't think I can predict these numbers
straight away.

-- 
Victor Sudakov,  VAS4-RIPE, VAS47-RIPN
sip:sudakov at sibptus.tomsk.ru