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Switch Help!!! Please

Zaits

I could use some advice here I am a bit confused...

I have a Cisco 2610 router connected to a 2950 switch and when I change the speed on the port its connected on to auto or even speed 100 the port either turns off or goes amber and does nothing... what am I missing here ?

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Comments

dynamik

Doesn't the 2610 only have a 10 mbps port? http://www.cisco.com/en/US/docs/routers/access/2600/hardware/installation/guide/2600ch1.html#wp1025557

I'm not sure why auto wouldn't work though.

mgeorge

Yes, the 2610, 2611 and 2612 have 10Mbps Ethernet

2620, 2621, 2650, 2651 and 2600XM series have FastEthernet

The duplex on the router should be set to Auto, not full or half. Typically you see that
both router and switch are manually set to 10/full to prevent errors or confusion like this

astorrs

Dynamik is right, set the port to 10-full.

If I remember correctly, Cisco originally implemented auto-negotiation differently than what became the standard sometime in 1998. So perhaps the 2950 comes from the 802.3 "standard" way of doing auto negotiation and the 2610 may do it the "Cisco only" way (since it was designed/released before the standard) so you're probably getting mismatches.

This is a guess on my part as to why it's not working, but it makes sense - I've never put those two together before.

APA

amber = collisions (duplex mismatch)

off = speed mismatch..... speed mismatches always result in a dead link...

either force it on both sides of the link to 10Mbps/Full Duplex or let auto negotiation do it's thing by setting both sides to auto-negotiate

Zaits

Thanks for your quick respones and everything you mentioned made sense. I have configured both to Full duplex not auto and set the speed to 10 also not auto and it works fine with no errors. I was just trying to figure out why this was the case but I didn't know 2610-2611 are only 10mbps

miller811

Zaits wrote:

Thanks for your quick respones and everything you mentioned made sense. I have configured both to Full duplex not auto and set the speed to 10 also not auto and it works fine with no errors. I was just trying to figure out why this was the case but I didn't know 2610-2611 are only 10mbps

during the configuration of the device if ithe connection is designated as e0 (ethernet) it is 10 and if it is f0 (fast-ethernet) is capable of 10 or 100.

Zaits

Well now I am really confused here goes...

E0/0 on Cisco Router2610 is set to Duplex Full
E0/2 on my Switch ( Cisco 2950) is set to Duplex Auto and Speed 10

This configuration I keep getting this message..

07:36:38: %CDP-4-DUPLEX_MISMATCH: duplex mismatch discovered on FastEthernet0/2
(not full duplex), with Cisco2610 Ethernet0/0 (full duplex).

Now if I change the switch from auto duplex to duplex full my internet connection is half the speed. I severly notice this from just downloading youtube videos. I am getting alot more collisions by having the configuration setup using auto though. What could possibly be causing this issue ?

dtlokee

If you hard code one side of the connection you may run into issues. When you are setting duplex full on the router, and the switch is set to auto, the switch will try to negotiate but the router won't respond, so the switch goes to half duplex which is a duplex mismatch.

astorrs

Have a look at my post from earlier in this thread, the router and switch can't agree on the duplex setting. Set the switch to full (as you said that's what the router is set to).

I don't see how correcting a duplex mismatch would do anything but improve your connection speed (since it reduces the number of packets that need to be resent). I wouldn't use YouTube videos as a way to determine connection quality/speed.

What is your internet connection? Is it also connected into this switch or is it on the routers serial port? Maybe there is something else mis-configured that is causing the perceived slowdown.

miller811

I am no expert, but the company I work for has been selling and I have been installing 2950 switches for well over 7 years. We either configure them at 100/full, auto/auto or 10/half. We have never configured the switches as 10/full.

I would hard code both sides at 10/half and see what you get.

you can always do a show int eX on the router or f0/X on the switch to look at the stats of the devices, and see how they are actually negotiating.

Zaits

Sorry I realize youtube is a terrible way to judge speed I was more or less saying its a night and day difference when downloading the same video. I have done speed tests and its twice the speed using 10/half on the switch as it is using 10/full. Also the Cisco 2610 doesn't allow for Auto Duplex its either full or half. I suppose I will just stay at 10/half for now on my switch but I would like to have it at 10/full if it was possible and I wasnt getting the duplex mismatch.