How to get DHCP setup?

By mbonanno ·
Currently, I have a range of IP addresses on a Cisco PIX for DHCP. I need to move the DHCP server to Windows 2003 Server. When I disable DHCP on the PIX, and implement the range on the Windows Server, machines that run out on their IP lease are coming up with limited or no connectivity. I have tried all IPCONFIG commands (flushdns, release, renew..)and rebooting the machine to get a new address to no avail. We have two PIX's on our network and each held a range of addresses; I was successful moving one but not this one. Any help would be appreciated!

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All Answers

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Network topology?

by robo_dev In reply to How to get DHCP setup?

To begin with, I assume that the Windows server is on the same LAN as the workstations?

If you assign a static IP in a PC, can you ping the DHCP server?

What OS are the workstations? Do they have personal firewalls installed?

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Network Topology

by mbonanno In reply to Network topology?

Thank you for the reply.

Everything is on the same LAN. I can PING the DHCP server from statically assigned Workstations.

All of the workstations are running Windows XP with SP2, and no firewalls are enabled.

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This may not be helpful but....

by robo_dev In reply to Network Topology

the next thing I would do is double check your DHCP scope on the server, make sure nobody mis-typed the gateway or anything.

I would plug a hub in-between the workstation and switch, and plug in a laptop running the (free) Wireshark packet sniffer utility, then you can watch the DHCP request/offer exchange as it happens (or does not happen).

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by mbonanno In reply to This may not be helpful b ...

I am hooking a laptop that is set to get an IP form the pix that runs out very quickly, by then the PIX will be disabled and I will be abel to see what is going on. WIll update shortly.

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Could it be?

by TobiF In reply to How to get DHCP setup?

What if something is wrong with the DHCP setup on your server, and the remaining PIX served the whole network with addresses. And when you disconnected the last PIX, there's nobody left to take care of DHCP requests?

Have you checked that at least some workstations sometimes receive addresses from the Windows server?

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RE: Could it be?

by mbonanno In reply to Could it be?

Thank you for the response. The windows server is picking up the addresses from the first PIX i shut off. I have included the 1st pix's range with the 2nd pix's range in the Windows DHCP. It will just not hand out any from the second range even though it is included.

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by mbonanno In reply to RE: Could it be?

I just had a lease run out on me, and the address went to a 169 address. It would not locate the windows DHCP server. I am using a 192.168.187.x and 192.168.186.x. The 186 is on the PIX, and 187 is on the WinServ. I took the 186 away from the Winserv so it would function for our users. THe laptop I used had a .186 address, and it would not find the 187's on the WinServ. Thoughts?

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by mbonanno In reply to DHCP

I still cant get this up and running. I totally killed DHCP on the PIX, and rebooted it. I resarted DHCP services on the Windows server, and rebooted a laptop to get a DHCP address, and it came up with limited or no connectivity. Its like it only wants to go to the PIX for an address, and there are none there. Thanks for any help that can be provided.

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Perhaps restart the switch?

by robo_dev In reply to DHCP

Make 1000% sure that the static IP of the DHCP server is in the same range as the DHCP pool defined on the server.

And make sure the scope is ACTIVE.

If you set a static IP in the PC and you can ping the Server, then set a workstation for DHCP, it should get an address that way, otherwise something in the server is hosed.

I would load up Wireshark on the workstation and watch the DHCP request/offer exchange.

The better way to do this is with a laptop and an ethernet hub between the client and server, but Wireshark can load cleanly on a workstation.

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