Help me with my DHCP/DNS issues, please!

MoGold · 09-15-2005, 08:17 PM

I have, for reasons too long to list, a rather convoluted network setup and I need help getting centralized DHCP/DNS worked out.

Network is, from the wall in:

CenturyTel DSL
Westell Wirespeed B90 DSL Modem
LinkSys BEFSR81 DSL Router
Westell A90/4 port gateway/wireless router upstairs
DLink BDI524 Wireless Access Point downstairs

DHCP/DNS Server is setup and all computers wired to the same subnet work fine. Both the Westell and the LinkSys have IP's on the wired network.

Machines that connect to the ports on the Westell or wirelessly to either, get DHCP/DNS from the wireless access points. If I turn off DNS/DHCP on the Dlink or Westell, the clients get nothing. How can I configure the Dlink &/or the LinkSys to pass DHCP/DNS up the network to the DHCP/DNS server?

Hope I explained that well enough and looking forward to any help you guys can give.

MonaG

**JamesO** · 09-16-2005, 07:39 AM

You should only have one device with DHCP/DNS enabled on the network. Usually a device that is closest to the modem is best. It is unclear how your network is configured, a simple diagram or better description would be helpful.

You probably have too many devices connected using the WAN port(s). You probably need to connect some of your devices only using the LAN port and it will most likely sort your issue.

Assuming your connection is like this:

DSL modem -> LinkSys BEFSR81 DSL Router -> Other devices.

Your LinkSys BEFSR81 DSL Router should have DHCP and DNS enabled.

Your Westell A90/4 port gateway/wireless router upstairs should have DHCP disabled and should be not be connected by the WAN port to the LinkSys BEFSR81 DSL Router. You should use a LAN port on your Westell A90/4 port gateway/wireless router to connect to the LinkSys BEFSR81 DSL Router. If the Westell A90/4 port gateway/wireless router has a web interface assign it a static IP address in the same subnet of your network, outside of the DHCP range.

I assume your DLink BDI524 Wireless Access Point only has one connection? If so there is no choice here. I can be connected to either the LinkSys BEFSR81 DSL Router or the Westell A90/4 port gateway/wireless router by a LAN port. If the DLink BDI524 Wireless Access Point has a web interface, assign it a static IP address in the same subnet of your network, outside of the DHCP range and different from the IP address for the Westell A90/4 port gateway/wireless router. If your DLink BDI524 Wireless Access Point supports DHCP, disable it.

JamesO

09-15-2005, 08:17 PM	#1 (permalink)
MoGold Registered User Join Date: Sep 2005 Posts: 1 OS: WinXP	Help me with my DHCP/DNS issues, please! I have, for reasons too long to list, a rather convoluted network setup and I need help getting centralized DHCP/DNS worked out. Network is, from the wall in: CenturyTel DSL Westell Wirespeed B90 DSL Modem LinkSys BEFSR81 DSL Router Westell A90/4 port gateway/wireless router upstairs DLink BDI524 Wireless Access Point downstairs DHCP/DNS Server is setup and all computers wired to the same subnet work fine. Both the Westell and the LinkSys have IP's on the wired network. Machines that connect to the ports on the Westell or wirelessly to either, get DHCP/DNS from the wireless access points. If I turn off DNS/DHCP on the Dlink or Westell, the clients get nothing. How can I configure the Dlink &/or the LinkSys to pass DHCP/DNS up the network to the DHCP/DNS server? Hope I explained that well enough and looking forward to any help you guys can give. MonaG

09-16-2005, 07:39 AM	#2 (permalink)
JamesO Join Date: Mar 2005 Location: Fairfax, VA USA Posts: 2,289 OS: 98SE, W2k Pro, XP Pro	You should only have one device with DHCP/DNS enabled on the network. Usually a device that is closest to the modem is best. It is unclear how your network is configured, a simple diagram or better description would be helpful. You probably have too many devices connected using the WAN port(s). You probably need to connect some of your devices only using the LAN port and it will most likely sort your issue. Assuming your connection is like this: DSL modem -> LinkSys BEFSR81 DSL Router -> Other devices. Your LinkSys BEFSR81 DSL Router should have DHCP and DNS enabled. Your Westell A90/4 port gateway/wireless router upstairs should have DHCP disabled and should be not be connected by the WAN port to the LinkSys BEFSR81 DSL Router. You should use a LAN port on your Westell A90/4 port gateway/wireless router to connect to the LinkSys BEFSR81 DSL Router. If the Westell A90/4 port gateway/wireless router has a web interface assign it a static IP address in the same subnet of your network, outside of the DHCP range. I assume your DLink BDI524 Wireless Access Point only has one connection? If so there is no choice here. I can be connected to either the LinkSys BEFSR81 DSL Router or the Westell A90/4 port gateway/wireless router by a LAN port. If the DLink BDI524 Wireless Access Point has a web interface, assign it a static IP address in the same subnet of your network, outside of the DHCP range and different from the IP address for the Westell A90/4 port gateway/wireless router. If your DLink BDI524 Wireless Access Point supports DHCP, disable it. JamesO