UDLD on Nexus 5548

[luke.smith]

Hi,

Does UDLD work between the Nexus 5548 and a Nexus FEX 2248 and would there be any benefit?

Thanks

Luke

[Mark Malone]

Hey I didn't think 2248s supported udld and for it to work right both sides 5 & 2 must be able to support it

You can check with show interface Ethernet x/x/x capabilities

I could be wrong now they may have changed it but I remember seeing before when I checked this it stated no under capability support for udld

[luke.smith]

Hi Mark,

Thanks for your response - I know the Ports on the FEX dont support UDLD but what about the Uplink ports? (FET ports to Nexus 5K)

These dont show as interfaces on the 5K

Thanks

Luke

[jg.vink01]

Hi Luke,

You can see the fex uplink ports with this command.

show interface fex-fabric

For more information:

show fex xxx detail

Greetz,

Jeroen

[russell.sage]

On a related issue if I enable the UDLD feature in a production network do all the fiber ports automatically enable UDLD, as per the documentation. Cisco Nexus 5000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.0(3)N2(1) - Configuring Ethernet Interfaces [Cisco Nexus 5000 Series Switches] - Cisco

Default UDLD Configuration

The following table shows the default UDLD configuration.

Table 1  UDLD Default Configuration

Feature	Default Value
UDLD global enable state	Globally disabled
UDLD aggressive mode	Disabled
UDLD per-port enable state for fiber-optic media	Enabled on all Ethernet fiber-optic LAN ports
UDLD per-port enable state for twisted-pair (copper) media	Disabled on all Ethernet 10/100 and 1000BASE-TX LAN ports