05-15-2012 08:16 AM - edited 03-07-2019 06:43 AM
I cannot seem to correct a duplex mismatch issue.
I have a Cisco 2950 switch connected to a Cisco 2621 router. I am running a per-interface Vlan. I have two fastethernet ports and one NM-1E card installed on the router. One fastethernet port is connected to my gateway router, the second fastethernet port is connected to my switch for one Vlan.
The NM-1E Ethernet card is being used for the second Vlan which consists of nine IP cameras.
Though the cameras on the Vlan are working fine, I am having major collision problems with the message being:
%AMDP2_FE-6-EXCESSCOLL: Ethernet1/0 TDR=0, TRC=0.
Now, the NM-1E card is set to half-duplex. I know that I should be using a fastethernet module like a 1FE 2W or a 2FE 2W card, (which I have,) but the router does not recogonize either one of these cards when they are installed, and yes, they have been confirmed as good cards.
Using Router-on-a-Stick configuration is out due to the bandwidth contention besides the fact that the router I am using it on will not handle this due to the flash being an older version.
Here is what I have done thus far to try to correct the collision issue:
I am open for suggestions at this point and have two addtional questions.
Again, I am open for suggestions at this point.
Thanks!
05-15-2012 09:20 AM
Hello Steve,
if you cannot configure duplex full under eth1/0 on the router the port is only half duplex
Is
interface eth1/0
duplex full
command accepted by the router ?
>>
Could nine IP cameras just be too much for both the router and switch to handle?
this is the point a 10 Mbps half duplex can perform at max 3.3 Mbps in theory even less in reality. It cannot run at 10 Mbps.
Even with low resolution ( = low bit rates) nine cameras easily overcome this figure.
The best move would be IOS upgrade in order to be able to:
- support vlan subinterfaces on FE port
- and to mount an FE additional module like one of those you have and that are not recognized at the moment
Hope to help
Giuseppe
05-15-2012 09:50 AM
Strange thing has occurred. I attempted to change the Ethernet port to full duplex and this time it took the command. I don't know why it didn't previously, and everything I read pointed to not being able to do this even though there was no confirmed NO to this configuration.
Once done, I forced the switchport into full duplex at the speed of 10 and now everything is GTG; all of the excessive collision messages have gone away as well.
Thanks!
05-15-2012 09:21 AM
If you cant change the interface from half duplex you have to live with collisions as this is part of a half duplex connection and is working as designed. Know that as the utilization goes up on half duplex link it will get slower and slower. Anything above 30-35% utilization on a half duplex link will make it real slow. You can't work miracles on very outdated technology .
05-15-2012 09:51 AM
Thanks,
As stated above, I attempted to change the duplex to full and this time the router took the command. Thanks for your help here as well.
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