DEGXA-SA causes link-flaps on Cisco.

[Christof Schoeman]

Hi

I'm not sure if this is the right place to post this question. If not, perhaps you can point me in the right direction.

We have several Marvel systems connected to Cisco 6500 switches, via DEGXA-SA Gig-E cards. Every time a system is shut down (or crashes), the Cisco switch disables the ports that the system is connected to, due to excessive link-flaps. The Cisco's are configured to disable the port if more than 5 flaps (link up-down) occur within 10 seconds.

We're seeing this on OpenVMS (pardon my French) as well.

The same happens when the system is initialised from the >>> prompt. Before the init the port would be open, after the init, it is locked.

Hope you can help.

[Mark Poeschl_2]

A couple things to check/try:

1) Do you have aggressive mode UDLD enabled on your ciscos? If so try disabling it.

2) Try disabling UDLD on those Cisco ports entirely.

3) I can't remember for sure if this is even possible with the -SA variant, but is there some way to disable any autonegotiation on both the Cisco port and the NIC

[Mikko Niskanen_1]

Should you run the 65XX in native IOS mode, e.g.
IOS 12.2SX, easier way is to nag those network guys and ask them kindly to enable error disable detection & recovery in global config:

Switch(config)# errdisable detect cause link-flap

Switch(config)# errdisable recovery cause link-flap

Switch(config)# errdisable recovery interval 30

30 seconds is minimun according to IOS command reference.

On the other hand, you could ask them to disable the errdisable feature from those particular ports. I see no reason why GE-connected server should have errdisable enabled.

[Christof Schoeman]

Thank you kindly for your replies.

Unfortunately, changing the global settings on the Cisco switches is not an option (been down that road). We're also having problems when not using auto-negotiation.

Not being a Cisco expert myself, I also have to take the word of the network engineer, that errdisable cannot be disabled for a particular port. Even if it was possible, I'd have a hard time to convince him that it would be "safe" to do so.

Perhaps the issue can be addressed on the system/NIC side. Why does the NIC do so many link-flaps when shutting down or init-ing the system? Could there be setting/config that prevents this from happening?

[Ralf Puchner]

Depending on the used chipset it is not wise to disable autoneg feature. Be sure your cabling is also correct, which means length and shielding.

[Christof Schoeman]

The latest Firmware (V7.0, I believe) solves this problem.