My situation is as follows. We are connecting from a 4510R (Sup V), WS-X4418-GB blade to a 3750G-48PS-E. The distance is around 1500 feet (MM fiber), patching fiber through one other location. When I use a WS-G5486 GBIC and GLC-LH-SM SFP with mode conditioning cables at each end, I see the numerous input errors (runts and CRCs).
GigabitEthernet1/7 is up, line protocol is up (connected)
Hardware is Gigabit Ethernet Port, address is 0021.555b.a73f (bia 0021.555b.a73f)
Description: to IDF07 SCAX009A01G; G1/0/50
Internet address is 10.147.15.162/31
MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
reliability 241/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 1000Mb/s, link type is auto, media type is 1000BaseLH
input flow-control is off, output flow-control is off
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:02, output never, 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 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
L3 in Switched: ucast: 5573 pkt, 416844 bytes - mcast: 0 pkt, 0 bytes
L3 out Switched: ucast: 0 pkt, 0 bytes - mcast: 0 pkt, 0 bytes
41492 packets input, 8972491 bytes, 0 no buffer
Received 35742 broadcasts (29759 IP multicasts)
7042 runts, 0 giants, 0 throttles
25996 input errors, 18954 CRC, 0 frame, 0 overrun, 0 ignored
0 input packets with dribble condition detected
57006 packets output, 9372991 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier
0 output buffer failures, 0 output buffers swapped out
When I connect this same 1500 foot link using a WS-G5484 GBIC and a GLC-SX-MM, I see no errors at all.
In other words, using MM throughout even though the distance is a bit out of spec, I see no errors. When I try to operate within spec and use mode conditioning cables with a single mode GBIC and SFP, I take errors.
If this were my only link, I would just run it out of spec (because it's not that far out). My overarching issue is that I have ten connections of long length, some up to 3000 ft through multiple other locations. I think that it's unlikely that running MM throughout all these connections will be successful.
Has anyone seen anything like this before? It almost seems as though the problem is isolated to the blade on the 4510. Perhaps I got a bad batch of GBICs and/or SFPs? Or bad mode conditioning cables?
Thanks for any thoughts.