10/100BT PCI Ethernet card causes LINK-FLAPS on CISCO Catalyst 3524XL

[Yves K]

We have build recently 2 HP Visualize C3600 Workstations with a PCI 10/100BT Ethernet NIC (+ on-board 10/100 NICs). All this NICs hook up to a CISCO Catalyst 3524XL switch. All NICs and switchport are configured to use the Auto-Negotiate option. This results that all NICs adapt their speed to 100FD, except for one PCI NIC. This particular NIC causes the switch to report following errors:
RTD-1-LINK_FLAP Fa0/9 link down/up 10 times per min
Even when setting both NIC and switchport to a fixed speed 100 and fixed full duplex, it still gives the error and the link toggles up/down.
Only when setting both ends fixed(NIC and switchport)to speed 10 and duplex full, the error dissappears and a stable link is established.
Does anybody have an idea why (auto-negotiation )it is working for the other NIC but not for this one? Both machine are identical with the same types of NICs.

[Pete Randall]

For 100BT, the standard recommendation is to force both the switch and NIC to 100FD and not to allow them to auto-negotiate. It just doesn't work right. The 1000BT, on the other hand, will only work properly with auto-negotiate.


Pete