09-27-2005 05:00 AM - edited 03-03-2019 12:11 AM
I have currently have two buildings connect via Multi-mode fiber. On each end there is a Transition Networks Fast Ethernet 100base-TX to 100base-FX media convertor (E-100BTX-FX-04(SC). The media convertor UTP/STP port is plugged into our Cisco 3570. Works great.
Within the last couple weeks, I had to buy another switch for growth on both ends. I got two Cisco 3570 with the 4 SFF Gbics slots. Then purchased 2 GBIC GLC-SX-MM. On one end I had to buy a SC to SC adapter and then get a MM SC to LC patch cable. On the other end I had to get a MM ST to LC patch cable.
Finally had an opportunity to plug everything in and try it out and I get nothing. No link light on the switch (at either end).
Any suggestions? Is there any testing I can do? If I plug one end to the GBIC and keep the other end in the Media Convertor box, should that work? Any help would be appreciated.
09-27-2005 07:47 AM
Hello,
can you post the output of 'show version' ?
You might want to start out with testing if your GBIC comes up when you plug both receive ends of the fiber cable into the GBIC, this creates a loop and should bring the GBIC up. Do the same for the transmit ends of the cable. If successful, it shows you that your GBIC, as well as your cable, are ok.
Regards,
GP
09-27-2005 07:54 AM
Wow, I'm having the same exact problem word for word. I hope someone knows the solution for this!
09-27-2005 10:54 AM
Yeah me too. This is really starting to irk me.
09-27-2005 10:54 AM
Thanks for the Help:
Here's the Show Version for the Stack at Main HQ.
Cisco Internetwork Operating System Software
IOS (tm) C3750 Software (C3750-I5-M), Version 12.1(19)EA1, RELEASE SOFTWARE (fc2
)
Copyright (c) 1986-2003 by cisco Systems, Inc.
Compiled Thu 23-Oct-03 22:52 by yenanh
Image text-base: 0x00003000, data-base: 0x009196DC
ROM: Bootstrap program is C3750 boot loader
BOOTLDR: C3750 Boot Loader (C3750-HBOOT-M) Version 12.1(11r)AX, RELEASE SOFTWARE
(fc1)
CMH_3750 uptime is 36 weeks, 2 days, 5 hours, 2 minutes
System returned to ROM by error - Debug Exception (Could be NULL pointer derefer
ence) Exception (0x2000)!, PC 0x1E53D8
System image file is "flash:c3750-i5-mz.121-19.EA1/c3750-i5-mz.121-19.EA1.bin"
---------------------
So If I plugin both GBIC into the same box, and then patch them with LC to LC - this should create a loop and have the lights come on? I just checked all my fiber cables and couplers and I don't have LC to LC or can't make one.
cisco WS-C3750G-24T (PowerPC405) processor (revision A0) with 118776K/12288K byt
es of memory.
Processor board ID CAT0736R0SK
Last reset from power-on
Bridging software.
7 Virtual Ethernet/IEEE 802.3 interface(s)
100 Gigabit Ethernet/IEEE 802.3 interface(s)
The password-recovery mechanism is enabled.
512K bytes of flash-simulated non-volatile configuration memory.
Base ethernet MAC Address : 00:0D:BC:69:66:00
Motherboard assembly number : 73-8046-05
Power supply part number : 341-0048-01
Motherboard serial number : CAT07360T2H
Power supply serial number : DTH073205Y4
Model revision number : A0
Motherboard revision number : A0
Model number : WS-C3750G-24T-E
System serial number : CAT0736R0SK
Switch Ports Model SW Version SW Image
------ ----- ----- ---------- ----------
1 24 WS-C3750G-24T 12.1(19)EA1 C3750-I5-M
2 24 WS-C3750G-24T 12.1(19)EA1 C3750-I5-M
* 3 24 WS-C3750G-24T 12.1(19)EA1 C3750-I5-M
4 28 WS-C3750G-24TS 12.1(19)EA1 C3750-I5-M
Switch 01
---------
Switch Uptime : 50 weeks, 4 days, 21 hours, 28 minutes
Base ethernet MAC Address : 00:0D:BC:1A:22:00
Motherboard assembly number : 73-8046-05
Power supply part number : 341-0048-01
Motherboard serial number : CAT073102R8
Power supply serial number : DTH0732067D
Model revision number : A0
Motherboard revision number : A0
Model number : WS-C3750G-24T-E
System serial number : CAT0735R17B
Switch 02
---------
Switch Uptime : 50 weeks, 4 days, 21 hours, 31 minutes
Base ethernet MAC Address : 00:0D:65:88:94:00
Motherboard assembly number : 73-8046-05
Power supply part number : 341-0048-01
Motherboard serial number : CAT072903D9
Power supply serial number : DTH072602Z7
Model revision number : A0
Motherboard revision number : A0
Model number : WS-C3750G-24T-E
System serial number : CAT0730X01V
Switch 04
---------
Switch Uptime : 26 weeks, 2 days, 19 hours, 44 minutes
Base ethernet MAC Address : 00:0D:BC:6A:2D:00
Motherboard assembly number : 73-7058-09
Power supply part number : 341-0045-01
Motherboard serial number : CAT073702WG
Power supply serial number : LIT07260075
Model revision number : B0
Motherboard revision number : A0
Model number : WS-C3750G-24TS-E
System serial number : CAT0737R1JP
Configuration register is 0xF
09-27-2005 11:26 AM
I'll save you some trouble. We've tried to attach both switches via fiber LC to LC and no luck. Got the same responce which is no responce. We did a loopback test via fiber ST to ST and at the other end ST to LC and same result which is nothing. Which all leads me to believe it's not a problem with the hardware at all. Some sort of setting that has to be set on those 3750's
09-28-2005 04:05 AM
That sounds about right too. I was think it could be the coupler, but probably more of a configuration issue. What does your config look like for the port? I'm using the GBIC port as a VLan... here's my config for the port at HQ.
interface GigabitEthernet4/0/28
switchport access vlan 14
switchport trunk encapsulation dot1q
switchport mode trunk
no ip address
On other ports I have the vlan 14 working just fine.
09-28-2005 05:43 AM
Perhaps I'm stating the obvious, but I haven't seen it in this thread...
Did anyone try swapping the TX and RX?
09-28-2005 06:15 AM
:)
Yep. Because of all the various patch cords, I built a chart and had a two way with another tech. We went through all the possible combinations, but still no link light / communication.
The thing is, the fiber is working now with the transceivers. So we know the TX and RX are correct.
09-28-2005 09:07 AM
hey try this. I would but I dont have access to my switch.
"Get on the switch and do a show interface status , the ports in question should show "not connect" if they are enabled . If they show disable then go into the interface and do a "no shut" command."
09-28-2005 11:37 AM
Yeah try that already too. Did a shutdown on it... made sure it listed as so and then did a No shutdown and it brought it back up but still lists:
GigabitEthernet4/0/28 is down, line protocol is down (notconnect)
Hardware is Gigabit Ethernet, address is 000d.bc6a.2d1c (bia 000d.bc6a.2d1c)
MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Auto-duplex, Auto-speed
input flow-control is off, output flow-control is off
ARP type: ARPA, ARP Timeout 04:00:00
Last input never, output never, output hang never
Last clearing of "show interface" counters 20w1d
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
0 packets input, 0 bytes, 0 no buffer
Received 0 broadcasts (0 multicast)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 0 multicast, 0 pause input
0 input packets with dribble condition detected
0 packets output, 0 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
09-30-2005 09:16 AM
what about:
int gig 0/1
no shut
for my situation, my WAN guy is saying it's a cabling issue but give that a shot. It should make the port live *IF* it's administravily shutdown
09-30-2005 12:47 PM
Keep in mind that 100baseFX can push much farther dis
tances than Gbics
here's what I found for the transceiver:
Transition Networks>
Cabling Type 100Base-FX, 100Base-TX
Data Link Protocol Fast Ethernet
Data Transfer Rate 100 Mbps
Optical Wave Length 1300 nm
Max Transfer Distance 12 miles
Status Indicators Link activity, power, link OK
Compliant Standards IEEE 802.3U
Gigabit ethernet with SX gbics can drive from 722 to 1804 feet, depending on the type of fiber. That's a big difference from 100FX.
Do you know the distance of the fiber between buildings?
(aside from that, you should be able to connect switch to switch and get the connection up - then try it across the fiber link)
HTH
09-30-2005 10:09 PM
I agree with Dan Owen, it sounds like a distance issue with the multimode fiber. Is it old fiber or new? 50-micron core or 62.5-micron? How far from one end to the other?
Multimode fiber that has been installed for years is good for 10BASE-FL (2000m in either half-duplex or full-duplex) or 100BASE-FX (412m in half-duplex, or 2000m in full-duplex).
1000BASE-SX runs on multimode fiber only, and can go 220m to 275m depending on the quality of the fiber, if it's regular fiber. There are new kinds of multimode being produced today that are rated by their manufacturers to carry SX out to 2000m. If you have old fiber, though, stick with the shorter limits.
1000BASE-LX (or Cisco's 1000BASE-LX/LH) can run on both multimode and single mode fiber. LX optical transceivers are more expensive than SX; and you may also need special mode-conditioning launch cables to make it work over the multimode; but if the end-to-end distance is 550m or less then this could be a solution for you.
If it's over 550m and old fiber, then you have two choices. Either (1) install some single mode fiber and use LX optics to go 5000m (standard) or 10,000m (Cisco); or (2), install additional pairs of 100FX-to-100TX media converters and set up a Fast EtherChannel between the two switches, if you have extra pairs of multimode strands on that run.
Hope this helps.
10-01-2005 09:18 AM
Hello,
have You checked the wavelength on both sides.
On multimode it can be either 850 nm or 1310 nm and on SM 1310 nm or 1550 nm. I think that's the problem.
/Tony
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