Solved by protecting the port with guard loop. Guard loop for the sudden loss of bpdu's on nondesignated ports.
Weird this is not mentioned in the l2pt docs, very plausible to happen. Erik ----- Oorspronkelijk bericht ----- Van: "Erik Klaassen" <[email protected]> Aan: "Aaron" <[email protected]>, [email protected] Verzonden: Zaterdag 31 augustus 2013 11:58:23 Onderwerp: Re: [c-nsp] MACFLAP loop with l2pt No port-fast on any port. i am using r-pvst. Before is goes in fwd it is first learning indeed. should a port go fwd when its not receiving stp bpdu's? Is this a wrong implementation of l2pt for stp? Erik ----- Oorspronkelijk bericht ----- Van: "Aaron" <[email protected]> Aan: "Erik Klaassen" <[email protected]>, [email protected] Verzonden: Vrijdag 30 augustus 2013 17:13:08 Onderwerp: RE: [c-nsp] MACFLAP loop with l2pt Are you port-fasting that sw2 g0/1 trunk interface ? I'm wondering why it goes straight to fwd prior to listening and learning ? ...i thought it would blk, list, learn, fwd... Aaron -----Original Message----- From: cisco-nsp [mailto:[email protected]] On Behalf Of Erik Klaassen Sent: Friday, August 30, 2013 8:36 AM To: [email protected] Subject: [c-nsp] MACFLAP loop with l2pt Hello, I have created a l2pt between sw1-gi0/1 and sw2-gi0/1 so both switches are logical connected. The te1/1 interface has the lowest cost so gi0/1 in sw2 goes in BLK state. When the connection between sw4 and the isp swich goes down, the link between sw2 and sw4 stays up but no bpdu's are received. gi0/1 in sw then goes in FWD state. So when the link between sw4 and isp comes up you have loop till some bpdu is received on sw2 gi0/1. How can i prevent this interface going in fwd state? What am i missing? Kind regards Erik gi0/1 do1q gi0/1 access vlan 170 vlan23 mode dot1q-tun, l2pt stp +-----------------+ +-----------+ | sw1 root br +--------------> sw3 | | | | | +-+---------------+ +-----+-----+ | te1/1 vlan 23 | | | | | trunk dot1q vlan 170 | | | +--------v---------+ | | isp l2 network | non cisco | +--------^---------+ | | | | | | | | trunk dot1q vlan 170 | | |te1/1 vlan23 | +-v----------------+ +------+----+ | sw2 |X |sw4 | | +------------> | +------------------+ +-----------+ gi0/1 dot1q gi0/1 access vlan 170 vlan 23 mode dot1q-tun, l2pt stp _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/ _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/ _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
