[c-nsp] UDLD enabling port prematurely?

[Lukas Tribus]

>> Very useful with optical links
>
> Why? If ethernet autonego provides this natively via RFI?

Autoneg is useful when either the TX or the RX fiber is
interrupted, however, when you have a hardware failure in the
sfp/linecard/asic etc (which causes an unidirectional link),
than you need UDLD to intervene.

/me has seen a layer 2 loop generated by such hardware failure,
autonegotiation didn't detect it.

However, UDLD is not useful in Victors' case, instead, I agree
that "spanning-tree loopguard enable" on the root port of the
remote switch is what will workaround the issue.




Regards,

Lukas