internet uplink Port showing blocking state

[HUSSAINQCS]

Hi,

Please i need help suddenly we removed the internet uplink from the core switch and connected still showing in blocking mode and it is not going to forwarding mode

[HUSSAINQCS]

Any urgent help is appreciated

[silvio]

blocked by spanning tree after reconnection of the same link like before? Did I understand correctly?

if the link is connected, do the following outputs:
> show spantree port active
> show spantree vlan xx (vlan of the uplink)
> show spantree cist

If you are sure that there isn't any loop than you can disable stp at the uplink port.

Or is it an other problem? try
> interface x/x/x admin-state disable/enable

regards
Silvio

[HUSSAINQCS]

I have created the vlans for clients and tagged all the vlans in all ports especially in 1/1/14 where the DHCP server up-link is connected



Clients will get IP from DHCP server(ANTlABS-3rd party server) connected to 6450



Network topology:


6450(1/26)-----------(1/1/14)6900---------(1/49)6450

I have attached configuration on 6900 and the vlans i created 1701-1747 it was showing port blocking for those vlans


Earlier the setup was in per vlan mode but i have created more than 252 vlans so Per vlan mode will not work and therefore i changed to Flat mode

and i have created the vlan 1701-1747 also so many created but if i enable the span-tree admin state then port is showing blocking for that vlans


What could be the issue ?

[devnull]

I'm not going to analyze 2500 lines of config.... some comments:
- you seem to have a wild mix of stp enabled and disabled for several vlans,
- you use telnet,
- you use static agg,
- you disable vlan 1 (which afaik has created issues in the past).

Do you really need all vlans to the DHCP? why not dhcp-relay?

Just to note: with flat mode you have one stp instance, that means only one tree. if you have a secondary port/path between two switches (even with different vlans) at the end only one path will be unblocked (regardless of which vlans will be on the port)

[HUSSAINQCS]

Thanks Devnull fro your reply