Hello! Thanks for you response.
As I know MSTP does not send MSTI's information in separate BPDUs, this information is piggybacked into the IST's BPDUs using special M-Record fields. They are all send UNTAGGED. They may be filtered (bpdufilter enable) or Carrier-Eqiupment may be configured not to forward them (may not be configured to forward them). To have alle vlans in one instance just don't map them, they will all in instance 0 . So, I can have multiple MSTI or one with whole vlan range (1-4096) no matter. Also we not planned to use some load share mechanism, so i did not see any sense in multiple instance. In any case, BPDU will be propagated in MST0 (Internal Spanning Tree) and will consist of such components as configuration name, revision number and a hash value calculated over VLANs to MSTI mapping table contents To form one region, the hash must be same, so the mapping/name/revision must be identical. The configuration name and revision parapeters have sense if we used multiple instase (maybe i'm wrong). But this is not acceptable for us now. They are mandatory. Did not work on my first 6 switches with MST-config without name and revision. I think that this problem may apear due very large L2 segment. So value "Max Hops" exhausts itself in some cases. As a result sw-core receives BPDU 0 and after that happens the following scenario sw-Core ceases to receive BPDU from all neighbors and and decides that he is root. Upstream switches sends superior root bridge information to the sw-Core bridge but receives the BPDUs with Designated bit set, the upstream switch concludes that the downstream does not hear its BPDU's. The upstream switch then blocks the downstream port and marks it as STP dispute link BUT Why sw-CORE ceases to receive BPDU from ALL neighbors? - a mystery. If your sw-core is HP than I would tell you "enable spanning-tree" it's off by default. Filter -Y see above Wll show spannint-tree tell you that running stp version IS MST ? (you can have mst config and pvrstp running, Show mst config will shot it even when pvst is active.) So what Switches do you use? Ensure identical MST configuration with name and revsion (textual identical on all switches helps a lot) And that all your switches have STP/MST running. Having WAN links with carrier-CPE'S/NT's ensure sufficient MTU and forwarding of BPDU's (and packet with destination-MAC=local-special-MAC-Address) Enable UDLD aggressive to find one-way links and disable them. _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
