Issue with acquiring IP address 1

[thetam]

Hi, we have a user that for whatever reason just can't get connected to our network each morning. the problem is fixed if i do the ip renew command but it's just won't get the ip automatically. the other 20 users don't have this problem. the odd thing is that if she connects to another switch and that switch connects to our main switch, the problem is resolved.

thanks!

 

[burtsbees]

Please explain the topology from her workstation to the dhcp device, and the topology of the same when it actually works.

Burt

 

[plshlpme]

is the cable bad going to that station? check the switch for errors...

maybe the pc nic card is buggy too?

 

[vipergg]

On the user port make sure portfast is turned on .

 

[chipk]

I'm with plshlpme - do a show interface and look for errors and resets. Also do a show log and look for link flap errors. If there are a lot of any of these, there may be a speed/duplex mismatch or perhaps a bad cable somewhere in between. If you keep her patch cable when you move her to another switch, does the problem follow her? If not, it's probably the switchport or the house wiring. It's not common, but individual ports do occasionally have problems.

 

[thetam]

well, the same calble is used when plugs onto another switch. i have tried using another port but didn't help. if the issue is on the switch end, what can we say about the other 20 users and they don't have any problem at all.

here is her topology that don't work.
she is connecting directly to a switch via a cat5. the dhcp server is outside of our network and resides on our ISP.

topology that works.
the only different is she connecting to a 8-port switch, and a cat5 connecting to the main switch from the 8-port switch that everyone connects to.

not sure about the portfast turned on... but would this question answered if already tried a known works port?

thanks.

 

[chipk]

It could be the switch because individual ports can "go bad". Try swapping things around to eliminate problems. Swap her switchport with someone else, i.e. if drop 100A is where the problem user is, and this goes to port 1 on the switch, and drop 101A goes to port 2 on the switch and the computer connected to this has no problems, try simply reversing the cables at the switch. If the problem follows the user, it's the PC that's the problem, if it stays with the switchport (goes to the other user) you know it's the switchport, if neither happens, then I'd suspect a config mismatch of some sort. You've just got to keep making changes (one at a time) until you eliminate possible problems.

 

[vipergg]

No you need to check the port setting on the switch itself in the config , if spanning tree portfast is not on the interface it is very possible that she may not be able to pull an address . A lot of this depends on where in the boot cycle the nic card actually brings up a link . If she has a pc that does not link up till late in the windows boot process and portfast is not turned on it will time out waiting for spanning tree to run which is about 40-50 seconds. Check the switch interface in the config .

 

[burtsbees]

vipergg is right on with that...I have seen that COUNTLESS times, and did not think of it at all! That should be the first thing to check!
If she plugs into a different port in the same switch, likely it is a spanning-tree issue, with it not coming up before Windows does its dhcp request---it will assume that there IS no dhcp server.
Does the user get the APIPA address?

Burt