Slow DHCP with Windows clients against dhcpd on Linux

[Karsten Breivik_1]

Hi all.

I recently discovered that IP address assigning per DHPC is really pretty slow when using my windows XP client against a linux based DHCP server.

At home, I use a linux based firewall. The firewall also doubles as a DHCP server, running dhcpd.

When connecting my laptop to the network at home, it takes 10-15 seconds to get an IP address. I thought nothing of it until I recently connected a box running FC5 Linux to the same network. The linux box would get an IP address immediately (within one second) when running dhcpcd. Why is that?

At work we are using Microsoft ISA server for DHCP, and when I connect my windows laptop to the network there, I also gets the IP address within a second or two, so I guess the windows side of things should be OK.

Is the windws DHCP client picky? My first thought is that the windows client must be waiting for something that the linux based dhcp server does not serve (domain controller, static route, wins-something, dns-something, etc), and then time out and settle for just the IP address when it does not get anything more...

Any ideas?

Pls see the attached config.txt file for dhcpd and windows config.

Brgds Karsten

[Steven E. Protter]

Shalom,

It could very well be the Windows server is being picky or needs to be patched.

There are a lot of jobs commonly done by Windows Servers that Linux boxes can do faster and more efficiently.

This is probably just one more example.

If the Microsoft Server is something you must live with, patch it up and consider filing a Microsoft support request. Just tell them Fedora Core 5 does it so much better they may hop a bit faster.

These services were designed for Unix/Linux. Microsoft provides ports of the service, sometimes poor ports in their bid to grab market share.

SEP

[Vitaly Karasik_1]

dhcpd messages from /var/log/messages may help to understand/fix this issue.

Rgds,
Vitaly

[Alan_152]

Are all things the same on both devices? Same NIC, same autonegotiation/duplexing/speed, etc? There are too many variables here to say what the critical factor is.

However, I would bet that if you found a copy of Dr. TCP and ran it on the Windows box, things would run a lot better. Windows is STILL optimized for dialup networking.