Hi All,
at the center of our network we have 2 x 3750 switches uplinked via their stackwise cable and configured with a number of FEC which are then used to provide a sort of redundant link to the distribution switches. The whole network is a single VLAN (1)
eg. 3750 GigabitEthernet1/0/1 goes to 2950 GigabitEthernet0/1
3750 GigabitEthernet2/0/1 goes to 2950 GigabitEthernet0/2
These two ports are then put in a FEC trunk (the non ISL type) and provide a high speed uplink to the distribution switches.
We have recently had a situation where the whole LAN sort of came to a halt, and the customer fixed the problem by removing 1 link from each of the distribution switches.
We have also found that some of the uplink ports from the 2950/3524 will go into err-disable mode and stop working until shutdown and no shutdown.
The network had been operating stable for a number of months, and I am not aware of any changes taking place.
One thing I have noticed is that the 3750 lost its role as root bridge of the vlan, so my first action is to make it the root again. Aside from this, what else can be done.
Even a distribution swtich with only 2 connected devices + 2 uplinks lost connection to the 3750 with ports going into err-disable mode.
Any suggestions are appreciated.
Cheers.
