03-05-2014 04:18 AM - edited 03-07-2019 06:32 PM
Hey there,
I connected "FE 0/1" (cisco 1841) to "Ethernet 1/0" ( NM-4E module in 2651 router). Both interfaces' status are up but their line protocol is down.
I sat both their speed to 10Mbps and their duplux to full but no luck.
Is this because i am using a straight-throught cable? According to my understanding all cisco routers uses "Auto-Mdix" feature which eleminates the need for cross-over cables.
Thanks,
Abdul,
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03-05-2014 04:23 AM
Hi,
Auto mdix needs autonegotiation and not all devices or modules support this feature.
Regards
Alain
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03-05-2014 04:22 AM
Abdul
According to my understanding all cisco routers uses "Auto-Mdix" feature which eleminates the need for cross-over cables.
Most switches support that feature but not necessarily routers. If you were using a switch module in the router then it would probably support it but i'm not sure the onboard ports do.
Jon
03-05-2014 04:23 AM
Hi,
Auto mdix needs autonegotiation and not all devices or modules support this feature.
Regards
Alain
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03-05-2014 09:52 AM
HI Alain,
Another good peice of information, I was not really aware of this. I was under the impression that auto mdix works and is independent of speed/duplex settings. There definitely must be a reason behind auto mdix needing auto nego ON. If you could put some light on that too please
Regards
Umesh
03-05-2014 10:08 AM
Hi,
although it is a very laconic explanation, it is explained here:
http://www.cisco.com/c/en/us/td/docs/routers/access/3200/hardware/guide/C3200ISR_HWRG/MR20fesm.pdf
Regards
Alain
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03-05-2014 09:12 PM
Alain,
You are right. As it turns out, the "NM-4E" module is very very old and it lacks autonegotiation feature thus no auto-mdix.
I used cross-over cables and everything works fine now.
Abdul,
03-05-2014 04:31 AM
Do you see something in log?
As I understand you have L2 issue - have you tried with static "half-duplex" on both sides?
HTH,
Dragan
03-05-2014 05:36 AM
Alain reminds us that auto mdix needs autonegotiation and Abdul tells us that he is hard coding the speed and duplex. I think that the simple thing is to try a crossover cable and see if the connection works with that.
HTH
Rick
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