Gigastack problem

Hello All

I have 3 C3550 switches with 12.1(22)EA8a software

On all interfaces with GigaStackiem Gibic module I have following errors:

Switch1#sh inter gi0/1
GigabitEthernet0/1 is up, line protocol is up (connected)
Hardware is Gigabit Ethernet, address is 000e.83f8.f999 (bia 000e.83f8.f999)
MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Half-duplex, 1000Mb/s, media type is CX
input flow-control is off, output flow-control is off
ARP type: ARPA, ARP Timeout 04:00:00
GigaStack module(0.2) in GBIC slot. link1 is down, link2 is up
Last input 00:00:00, output 00:00:06, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 1166000 bits/sec, 262 packets/sec
5 minute output rate 258000 bits/sec, 132 packets/sec
1790800513 packets input, 4251114764 bytes, 0 no buffer
Received 56486614 broadcasts (0 multicast)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 48798068 multicast, 0 pause input
0 input packets with dribble condition detected
1128848985 packets output, 1088404885 bytes, 0 underruns
0 output errors, 557557 collisions, 1 interface resets
0 babbles, 0 late collision, 4351621 deferred
0 lost carrier, 0 no carrier, 0 PAUSE output
0 output buffer failures, 0 output buffers swapped out

With which could be a problem? Configuration of gigastack -> change or try to change for Full-Duplex GigaStack Star Configuration? Or problem can be with GIBIC module or fiber optic cables?

Regards

The collisions are a direct result of half-duplex and will disappear when you code it to full. Deferred....Deferred means that the adapter had to defer while trying to transmit a frame. This condition occurs if the network is busy when the adapter is ready to transmit. The adapter will only defer the first attempt to send a packet. After that the adapter will transmit the packet without checking. If the network is still busy then a collision will be recorded. Full-duplex will allow transmission in both directions at once, removing the wait state and deferring packets.

This is a Gigastack Half Duplex connection, two routers are connected by one cable, if you want full duplex you have to connect two routers by two cables (point to point). You can not configure full or half duplex manualy on gigastack, it depend by your network connections.

www.cisco.com/en/US/products/hw/modules/...07d1f6.html#xtocid12

I was looking on cisco.com (above)

You only need to cable them differently (?)

figure 2-6, 7 and 8 show the different configurations.

IMHO I can't see why anyone would want to run connectivity between gig switches in half duplex, kinda like two steps forward, one step back.

I'm hoping you can explain the benefit of introducing a collision domain
(if that what is truly happening.)

Thanks

Sorry about blowing out the margins, it happened when I pasted the link and didn't realize it.

Hi,

I've checked that network and with gigastack is everything ok, this conn. looks like on that cisco page. But I still don't know why that erros apear.

I've checked similar network, connections between switches and configurations are the same. There is 1000/half duplex too, but there is no errors.