09-11-2008 03:01 PM - edited 03-03-2019 11:30 PM
Hi All,
My quetsion is to do with sending DHCP requests across the WAN using the IP Helper-address command.
Our networks located in Australia and our WAN circuits are MPLS provide by Telstra, the national telco. We connect to Telstra by an ethernet link so we do not have any MPLS configuration on our WAN routers.
When I configure the IP Helper-address on our remote site routers and attempt to renew or reboot a PC at the remote site we are not able to get a new IP address. Also, Ip accounting does not show any connections to the DHCP server.
If anyone knows of any MPLS restrictions concerning DHCP requests I'd be grateful if you would let me know.
Cheers
Neil
09-11-2008 07:44 PM
I have worked in the similar scenario and I never came across any issues which relates to MPLS. Possibly the issue might be because of some other thing.
Try pinging the DHCP server from the remote router.
Check whether a DHCP scope is crated for the remote sites on the DHCP server ???
Do some troubleshooting and I guess this is not some thing related to MPLS.
Thanks
Rajesh
09-12-2008 09:52 AM
Any reason you can't put it on the router or switch at the remote site? You might lose some functionality over using Windows DHCP, but for a remote site, you really don't have much to lose.
HTH,
JB
09-12-2008 10:49 AM
Neil
I agree with Rajesh. The last place i worked we had an MPLS network and all our remote sites got IP addresses from our data centres.
The remote site router receives the DHCP broadcast from the client and then sends a unicast packet to the configured IP helper-address(es). So it is just another IP packet across the MPLS network.
It's not clear where you are running the IP accounting, could you perhaps run a network monitor on the DHCP server to see if requests are being received.
Jon
09-12-2008 11:20 AM
Check whether you added the ip helper address on the correct vlan interface on the L3 switch .
HTH
Ullas
09-14-2008 05:27 AM
same as Rajesh, I am using the set up u described without any issues.
if u can ping DHCP but not getting PC to boot, check:
1-IP helpe is on right VLAN as per previous poster.
2-Check DHCP is configured correctly as per previosy poster.
3-Check FW is allowing DHCO Discovery packets.
4-Check DHCP and FW logs for additional help.
HTH
Sam
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide