UDLD on Cisco Catalyst 4006

[dkblee]

Hi! If i enable udld globally, will it take effect on all the modules as well?

I tried to enable udld on a few module's ports, but the system prompted me something like... you must enable globally first.

Any advise?

Another question is that when i issue a command

set trunk 2/1 nonegotiate dot1q

1025-4094, will also be displayed in that interface when i run the command show conf. Do i have to clear trunk for 1025-4094? My understand is that by default there's only 1-1005.

Thanks.

[glen.grant]

I believe you have to enable globally first then disable any ports you don't want it on . Vlans 1025-4094 are extended vlans and must be manually cleared off the trunk if you don't want them running across the trunk...

[jstoecker]

My understanding is that when you enable it "globally" you are really enabling it on all fiber-optic links within the chassis but not on any others; copper links must be individually configured if you want it on them also. (it's a substantially lower probability that a copper link will be or can become unidirectional)

I believe whether you're in VTP transparent mode or not may have some impact on what the default VLAN range is.

John

[chrihussey]

When you enable UDLD globaly the default is UDLD will be enabled on all fiber based ports and is disabled on all copper based ports. You can then disable (or enable) it on the ports that you wish.

Also, just as an FYI, if the remote end switch port does not have UDLD enabled, then UDLD will not function and it will not disable the port.

With regard to your second question, according to the documentation, the default is 1-1005, 1025-4094.