Dear Colleagues, There is a ring of EX4200 switches, please look at http://noc.sibptus.ru/jun1.png
If MUX1 fails, the MSTP topology adjusts and the PCs continue to see one another just fine. However, some switches become inaccessible in the management vlan (vlan3 in this example). For example, you can still ping 192.168.1.3 from 192.168.1.2, but not 192.168.1.4 from 192.168.1.2. One important note. If MUX1 fails, the corresponding interfaces on 192.168.1.2 and 192.168.1.4 don't go down, it is only the traffic (including BPDUs) that stops flowing through the mux. If I shutdown the corresponding interfaces on 192.168.1.2 and 192.168.1.4 (or use OAM to shutdown the interfaces automatically when the mux fails), the problem disappears and I can ping any switch from any switch. What's the theory behind this? "clear arp" and "clear ethernet-switching table" don't fix the problem. -- Victor Sudakov, VAS4-RIPE, VAS47-RIPN AS43859 _______________________________________________ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp