STP Question

Ahmede · ‎01-24-2008

We have two 2950 desktop switches connected back to back, and each of these switches are connected to a 4507, and the two 4507 are connected to each other, so the 4 swicthes are creating a square.

One of the 4507's is the STP root for the VLAN, and the second 4507 is the secondary root. We need to configure the loop guard and the root guard, in our setup where should we configure root and loop gurad? Which interfaces?

Thanks in adavance..

Edison Ortiz · ‎01-24-2008

I suggest you do some reading on understating both features at:

http://www.cisco.com/en/US/docs/switches/lan/catalyst3560/software/release/12.2_37_se/configuration/guide/swstpopt.html#wp1031307

HTH,

__

Edison.

shrikar.dange · ‎01-24-2008

hi,

as edison said one should have the deep understanding to play with STP.Plz go through the link provided by edison.

For quick note:

Root guard: It provides a way to enforce the root bridge placement in a network.If a s/w recives a superior BPDU on a root guard enabled port,then that port moves to root inconsistant state and it will not fwd ne trffic on that port.

Enable root guard on all access ports.

Loop guard:If switches stop receving BPDUs on a nondesignated port with loop guard feature enabled that port goes in to loop inconsitant state providing protection against possible L2 loops.

Enable loop guard on all nondesignated ports and blocking ports.

Loop guard and root guard can not be enabled on a same port.

HTH,

regards,

shri :)