Cisco 4506E random port problem, no ip.

[rhjansen1]

We have a network with Cisco 4506E switches with mostly 240 ports per switch. The last year we have at 5 switches randomly problems with ports at different blades. (WS-X4548GB-rj45). The ports all have the same configuration. Suddenly we have ports which don't give an IP to the computers and IP-phones. When we powerdown the switch the problem is solved, all ports are working fine. About 6 weeks later we have the same problem on several ports again. Not on the same ports but just randomly. We already changed several supervisor cards (also in the version 5 card) but this doesn't solve the problem. Strangly we have this problem only at 4506E-chassis. Anybody recognize this problem or know the answer to solve it?                   

[Peter Paluch]

Hi Ronald,

I have not come across a similar problem but I wonder - do you happen to use DHCP Snooping? Can your issues be caused by this feature?

Best regards,

Peter

[rhjansen1]

Hi Peter,

we do use DHCP Snooping , but this has no relation to this problem. We have a big network, all our switches are configured  the same, we only have this problem on these 5 switches.

Best regards Ronald.

[Leo Laohoo]

Strangly we have this problem only at 4506E-chassis.

Could be an IOS bug.  Have you tried upgrading the IOS?

[rhjansen1]

Hello Leo

We use in all our switches the same IOS version 12.2.53 but this problem is only in these 5 switches. I asked my question to see if this problem is a bug and others recognize this problem and know the solution to solve this problem.
We opened a year ago a TAC case at Cisco but up until now they didn't really helped us to solve this problem.

Regards Ronald.

[dominic.caron]

  Do the port stop sending power to the phone?

[rhjansen1]

Hello Dominic,

the phones are getting power but pc and phones are getting no IP (no traffic). The pc does get an IP-adres but has no traffic, which means you can't login and internet is not working, the phones are getting a status in the display "discover IP" but this also seems a traffic problem. All other ports/interfaces are working fine and even if you give the switch a powerdown then the problem appears to be solved only six weeks later the same problem comes back on random ports. Luckely not on many ports, which means we give the user an other port as long as we have ports available.

Regards Ronald.

[wwsmith]

HAve you run out of addresses in DHCP scope for VLANs on these switches?