[nsp] Cisco Cat 3550 buggy FastEthernet

[Andrey Koklin]

Hi,

We've got a bunch of Catalists 3550, and experience now problems
with connecting our old equipment.

It'd worked fine when connected to Cat2900/3500 XL,
but after switching to 3550, we have big number of CRC errors
(up to 90% of packets loss) for such equipment:

1. Catalyst 2820 Enterprise (last released firmware cat2820EN.9.00.06)

When connected to c3550, through standard 100BaseTX module
(Full-duplex, 100Mb/s on both sides, whatever flowcontrol)
there is about 20-90% packet loss, depending on packet size.

2. Different 10baseT devices -- like, WaiLAN Agate 700, etc.

Half-duplex, 10 Mb/s. The same CRC errors, when connected to c3550.
One cure I found -- to put a 10baseT hub between the device
and the switch.
Anoter (as I was told by a man, who makes networking equipment and
have the same problems) -- to put a low-pass filter on the device's
output with some capacitors.

3. Some PC network cards, like 3Com 905TX, with old drivers.

E.g., one of our branches have a Linux server, with 3Com 905TX card
with old Boomerang driver. It works fine when pluged into Cat2924XL,
while with c3550-48 there is big number of CRC errors on the port.

4. Who knows?


I don't know, perhaps Cisco 3550 are standard compliant,
but they arise some serious problems with other equipment.
Well, seems, they don't work well even with a native equipment,
like Cat2820.


-- 
Regards,
Andrey