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UDLD and Loop guard

welcomeccie
Level 1
Level 1

Cisco Recommends to enable UDLD on etherchannel and Loop Guard on Non designated ports(Root and backup) . if there are 2 core with STP loadBalancing so the EtherChannel will be No-designated for some vlans So my questions is that Can i enable both of UDLD and Loop Guard on the etherchannel ports?

4 Replies 4

bvsnarayana03
Level 5
Level 5

UDLD & loopguard are the methods of preventing abnormal conditions in stp due to unidirectional communication. When udld is enabled on interface, it sends udld pkts & waits for the response from connectd neighbor. If its not recvd, udld considers the interface as unidirectional & shutdown.

Manual intervention required to make the port operational.

Loopguard on the other hand, puts the port in loop-inconsistent state in case of unidirectional condition i.e. when bpdus are sent but not recvd. When the port starts recving the bpdus, again stp calculation is run & port is transitioned to a suitable state. no manual intervention required. Loopguard only aplies to active vlan instances on the port.

Hope that clarifies, which option is better.

Core1 ---Etherchannel----Cor2

| |

|-------Edge1------------

Thank you for your reply .But can i apply both of the UDLD and Loop guard on the etherchannel?

my thought is to have loopguard, as there is no manual intervention required.

But cisco Recommends to use UDLD in etherchannel and use desirable mode too so can i apply loop guard too with UDLD

I appreciate your reply

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