Overclock.net banner

No link activity on Catalyst 2950 network switch.

168 views 7 replies 4 participants last post by  raidmaxGuy 
#1 ·
I really hate posting so much as of late but I just moved into an apartment and everything technology related has been a challenge

Having a hard time wrapping my head around this one. I had a defunct cat 5 cable that I put a new terminator on and it seems to work fine with it plugged into a 10/100 switch in another room and connected directly to a computer. I can get an IP lease and access the internet. However, if said cable is plugged directly into the 2950 switch, there is no link activity and it does not show up on my network.

Interestingly enough. If i put a second switch (Linksys Workgroup switch) and have the following route: Router->D-Link SOHO switch->long network run->Linksys workgroup switch->6 ft patch cable->Catalyst 2950 gigabit port, it has a strong enough signal to initiate link activity and the 2950 switch shows up on the network. Even this way is problematic because the collision light stays solid on the Linksys switch for the patch cable that goes into the 2950 switch.

I hope im not being to vague or confusing here, but I am a bit lost as what to do. I do not have any sort of cable tester to see if there is a break somewhere or a crossed wire. Can someone offer some advice as what to try?
 
See less See more
#3 ·
Did you wire the cable straight-through, or did you switch the RX/TX pairs around? Your new switches probably Auto-MDX on them which will toggle the send/receive pairs as needed to communicate, but the Catalyst switch probably does not - at least not without setting an option in the CLI for the port you're hooking to. It's something to check anyhow.

Another possibility is that you have a bad connection in the cable after putting the new end on. Gigabit Ethernet requires all 8 wires (4 pairs) an 10/100 Ethernet only requires 4 wires (2 pairs).

Greg
 
#4 ·
Quote:
Originally Posted by hammong View Post

Did you wire the cable straight-through, or did you switch the RX/TX pairs around? Your new switches probably Auto-MDX on them which will toggle the send/receive pairs as needed to communicate, but the Catalyst switch probably does not - at least not without setting an option in the CLI for the port you're hooking to. It's something to check anyhow.

Another possibility is that you have a bad connection in the cable after putting the new end on. Gigabit Ethernet requires all 8 wires (4 pairs) an 10/100 Ethernet only requires 4 wires (2 pairs).

Greg
Well I wire all my cables to T-568A standards and it is the same on both ends. I wish I could say it were an issue with going from gigabit to 10/100 on the other end but it seems like the 10/100 ports dont get anything either.
 
#5 ·
Quote:
Originally Posted by raidmaxGuy View Post

Well I wire all my cables to T-568A standards and it is the same on both ends. I wish I could say it were an issue with going from gigabit to 10/100 on the other end but it seems like the 10/100 ports dont get anything either.
Also, all of the switches are from around the same time period. The 2950 shipped with a late 2007 IOS firmware installed. The D-Link switch I am using is the following:
http://www.amazon.com/D-Link-DSH-5-Dual-Speed-Auto-Sensing/dp/B00002JUZ8/ref=cm_cr_pr_product_top

I see it has auto sensing nway but I cant see how that is an issue. I was able to use a Gigabit ProSafe 8 port switch with the 2950 that had the same features as the D-link, except for differing duplexes.

You did just give me the idea to replace the D-Link with the Linksys.
 
#6 ·
Putting the LinkSys switch in place of the D-Link caused some changes. I read up on the manual and I apologize about assuming collision issues. It turns out that the solid COL light is actually a dual purpose light (FD/COL). When they are solid amber it indicates a Full Duplex link. Here is where we run into another issue. The same run that goes to the 2950 switch is only running at Half Duplex 100

Edit: Changing over to a 10/100 port solves the problem. I will be running CNA to see if those gigabit ports are configured incorrectly, I might just use both of those to connect my server to.

Edit again: A quick change of duplex negotiation and speed to auto in the configuration eliminates the half duplex issue. I hope to upgrade to full gigabit network hardware at some point. But right now i am strapped for cash. I know it wont help my 25mbps internet service much but there is so much intenal network traffic with two full time file servers going.
 
#8 ·
Quote:
Originally Posted by tompsonn View Post

My first thought was the port was shutdown
tongue.gif
It wasnt shut down, it was just that it was configured to forced Full Duplex and 100mb link speed. Those are both things that I needed but somehow with it not set to auto, something was screwing up.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top