i cannot retrieve an ip address from the dhcp server?

[dparmar89]

i am currently using packet tracer and have a WAN cloud with two routers attached to it which are configured with frame relay and can ping one another with one of them configured as a DHCP server. Pc's on the same LAN as the DHCP server can retrieve an ip address but pc's on the other LAN cannot get an ipaddress from the server. I am sure frame relay is configured correctly an also have a static route in place on the router not configured with DHCP.

Help please. let me know if more info is required.

[cadet alain]

Hi,

Routers stop broadcasts so you surely need to enable DHCP relay on the router on the other end of FR cloud with the ip helper address which will translate your broadcast into unicast.

let's assume your client is connected to 192.168.1.254 on router and the DHCP server is 172.16.12.254 then on your LAN interface you must enter command: ip helper-address 172.16.12.254 and don't forget to configure a DHCP pool for the 192.168.1.0/24 subnet on your DHCP server router.

Regards.

Alain.

[dparmar89]

i'll try that out, thanks for your help Alain.

[dparmar89]

hi i tried the iphelper address but the pc will still not retrieve an ip address i also forgot to mention i have several vlans setup on the DHCP router and have address pools setup for each 1

[cadet alain]

hi,

post your packet tracer file.

Regards.

Alain.

[dparmar89]

here you go, appreciate the help

[cadet alain]

Hi,

I don't see any DHCP client on the left of your DHCP server, all the hosts are not configured for ip addressing.

Where is the ip helper command on ABC-London router?

The subnets in London are the same as in Birmingham so it can't work.For Birmingham these subnets are directly connected.

Regards.

Alain.

[dparmar89]

hi, i've placed an ip helper address on the london router on both interfaces and have setup all clients for dhcp.  How would i go about changing the subnets for Bham and london  as im a little confused as to what do in response to your last post.

thanks

[cadet alain]

The student PC and Staff PC on  London LAN are not configured for DHCP and they haen't got any static IP either.

I don't see any ip helper address on the subinterfaces of London router.

For the subnets I mean you have  .10/24, and others on both LANs so you could  use 11/24 instead and so forth on London LAN and create new pools on Birmingham router and configure ip helper on each subinterfaces of London to Frame relay interface of Birmingham and also put a route to the London LANs on Birmingham(static network routes) and same on London for Birmingham routes.

Regards.

Alain.

[dparmar89]

hi, for testing purposes i changed just  the .10/24 subnet to .11/24 i have not yet created a pool on the dhcp router but when trying to ping the dhcp router it does not work however i can ping the london router.  I have also put a ip helper-address on the subinterface

[cadet alain]

pinging dhcp router from where?

Alain.

[dparmar89]

from the staff pc on the london LAN

[cadet alain]

So you need a route for London LAN on the Birmingham router

Alain.

[dparmar89]

hi, i have put a static route on the bimingham router to the london router and still not working. Going back to what you mentioned on DHCP not serving two lans over a WAN, would it be easier to maybe setup each router as a DHCP server for each LAN and creating a pool of addresses for each of those?

[cadet alain]

would it be easier to maybe setup each router as a DHCP server for each LAN and creating a pool of addresses for each of those?

Yes it would but if you want your LANs to communicate then your subnets must be different or else use NAT or more complicated scenarios like I mentioned before.

REgards.

Alain.