Solved: Switches and DHCP

Status
This thread has been Locked and is not open to further replies. Please start a New Thread if you're having a similar issue. View our Welcome Guide to learn how to use this site.

Doghnut

Thread Starter
Joined
Jan 18, 2011
Messages
2
Apologies if this a repeat -- I searched the forum and found no duplicates.

I run a smallish LAN at work (30-70 computers depending on the day). I am having a problem with connecting to my DHCP server through an unmanaged switch.

I have only one ethernet port in a particular room and need to connect 3-4 computers through that port. It is my understanding that an unmanaged switch should do the trick (correct me if I'm wrong).

The problem I have is that I cannot get more than 2 computers to get an IP from DHCP. It's a different two computers everytime -- it just seems that it's a race to the DHCP server and once two computers get there, the others are locked out.

Various things I have tried:
-Static IPs have no bearing.
-Forcing a NIC to use reduced speeds makes no difference.
-The switch is Auto-MDIX
-The problem persists whether using regular switch ports or the uplink port.
-I have also tried a second switch I own with the same problem.
-Windows firewall is disabled and turning off anti-virus makes no difference.
-My scope has not run out of IPs.

Is there something I am missing here? I feel like the problem is simple or fundamental and I'm just not seeing it.

Thanks in advance for any help you can give.
 
Joined
Aug 13, 2010
Messages
255
That is very strange. Right now, I am as puzzled as you are.

With this setup, how many switches are there between the affected PCs and the router/gateway?

From the room with the 4 PCs, how far is the next upstream device (switch/hub/router)?

I guess you already know that as a last ditch, you can go with the DHCP reservations, and then statically configure each of the PCs for the DHCP server's reservation? With this setup, I would be interested in knowing if the 4 PCs can then all simutaneously ping the gateway IP (ping -t [gatweway'sIP]).
 

Doghnut

Thread Starter
Joined
Jan 18, 2011
Messages
2
Sorry for the long time in response -- I appreciate the help Pedro.

Of course, I had this problem for weeks and as luck would have it, I figured it out as soon as I posted here. It turns out that each of our ports runs through a set of Cisco switches which are much more intelligent than I previously thought. I had to configure each port to accept the correct connection.

I will mark this thread as solved in case anyone else ever experiences a similar problem.
 
Status
This thread has been Locked and is not open to further replies. Please start a New Thread if you're having a similar issue. View our Welcome Guide to learn how to use this site.

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

As Seen On
As Seen On...

Welcome to Tech Support Guy!

Are you looking for the solution to your computer problem? Join our site today to ask your question. This site is completely free -- paid for by advertisers and donations.

If you're not already familiar with forums, watch our Welcome Guide to get started.

Join over 807,865 other people just like you!

Latest posts

Staff online

Top