DHCP failes with 2nd router installed ISDPCMAN 11/14/2008 2:16:12 PM I have a typical branch office setup. Main office has a Sonicwall VPN router connecting to a Sonicwall VPN at branch. Windows Server 2003 is setup to service DHCP. In the past, all internet traffice goes from branch to main, then out to the internet. We got cable intenet in branch office now which is 20x faster than current connection through VPN so we got a new gateway to handle that. With second router installed now, DHCP to the branch fails. Here's the setup: Main office LAN: 10.10 9.x / 24 Main office gateway: 10.10.9.1 Branch office subnet: 10.10.8.x / 24 Branch office VPN router: 10 10.8.1 Branch office gateway: 10.10 8.5 <new router for internet> I have setup DHCP at the server to accomodate this branch office scope as follows: Subnet: 10.10.8.1-10.10.8.254 Exclude: 10.10.8.1-10.10.8.100 Router: 10.10.8.5 <new internet router> Option 249 (classless route): 10.10 9.0 255.255.255.0 10.10.8.1 If I refresh a PC at the branch it loses DHCP and I get an APIPA address. If I configure statically (e.g. 10.10.8.99 / 255.255.255.0 / 10 10.8.5) i can hit the internet just fine but not the main office server. So I added a static route to the PC with: Route add 10.10.9.0 mask 255.255.255.0 10.10.8.1 This now lets me do everything correctly but I cannot use DHCP (not good if we add or need to change configurations.) Question is: Why can't any machine find the DHCP server and get an address? I have setup a route in the new gateway to this .9.0 subnet; I have DHCP passthrough setup on the new router as well as the VPN router. If I turn off the new gateway and just use the VPN router I get DHCP again. Any thoughts are helpful.

Re: DHCP failes with 2nd router installed "Anthony [MVP]" <anthony[ at ]no-reply.com> 11/14/2008 6:01:32 PM I am not sure if I understand you correctly, but it sounds like: - the new cable router gateway needs to have an IP Helper address of the DHCP server in order to forward the requests. - the cable router needs to have a default next path of the ISP, and a route for 10.10.9.0 via the VPN router. Anthony, http://www.airdesk.co.uk "ISDPCMAN" <ISDPCMAN[ at ]discussions.microsoft.com> wrote in message news:3512856B-CECD-49FD-AB03-91DFA8B18F52[ at ]microsoft.com... [Quoted Text] > I have a typical branch office setup. Main office has a Sonicwall VPN > router > connecting to a Sonicwall VPN at branch. Windows Server 2003 is setup to > service DHCP. In the past, all internet traffice goes from branch to main, > then out to the internet. > > We got cable intenet in branch office now which is 20x faster than current > connection through VPN so we got a new gateway to handle that. With second > router installed now, DHCP to the branch fails. Here's the setup: > > Main office LAN: 10.10 9.x / 24 > Main office gateway: 10.10.9.1 > Branch office subnet: 10.10.8.x / 24 > Branch office VPN router: 10 10.8.1 > Branch office gateway: 10.10 8.5 <new router for internet> > > I have setup DHCP at the server to accomodate this branch office scope as > follows: > Subnet: 10.10.8.1-10.10.8.254 > Exclude: 10.10.8.1-10.10.8.100 > Router: 10.10.8.5 <new internet router> > Option 249 (classless route): > 10.10 9.0 > 255.255.255.0 > 10.10.8.1 > > If I refresh a PC at the branch it loses DHCP and I get an APIPA address. > > If I configure statically (e.g. 10.10.8.99 / 255.255.255.0 / 10 10.8.5) i > can hit the internet just fine but not the main office server. So I added > a > static route to the PC with: > Route add 10.10.9.0 mask 255.255.255.0 10.10.8.1 > This now lets me do everything correctly but I cannot use DHCP (not good > if > we add or need to change configurations.) > > Question is: Why can't any machine find the DHCP server and get an > address? > I have setup a route in the new gateway to this .9.0 subnet; I have DHCP > passthrough setup on the new router as well as the VPN router. > > If I turn off the new gateway and just use the VPN router I get DHCP > again. > > Any thoughts are helpful.

Re: DHCP failes with 2nd router installed ISDPCMAN 11/14/2008 9:33:00 PM As indicated, I do have a route setup in the .8.5 gateway router to point any ..9.x traffic to the .9.1 router. The VPN router still has its original configuration to go to the .9.1 router for 10.10.9.x traffic. DHCP passthrough is setup on both the VPN router and the .8.5 gateway.

Re: DHCP failes with 2nd router installed "Anthony [MVP]" <anthony[ at ]no-reply.com> 11/30/2008 8:40:19 AM Can you turn off the DHCP in the cable modem altogether? Then the old VPN router should handle the request as it used to do, Anthony, http://www.airdesk.com "ISDPCMAN" <ISDPCMAN[ at ]discussions.microsoft.com> wrote in message news:81FDD5AD-0101-4694-81AB-F4F804636E16[ at ]microsoft.com... [Quoted Text] > As indicated, I do have a route setup in the .8.5 gateway router to point > any > .9.x traffic to the .9.1 router. The VPN router still has its original > configuration to go to the .9.1 router for 10.10.9.x traffic. > > DHCP passthrough is setup on both the VPN router and the .8.5 gateway.

Re: DHCP failes with 2nd router installed ISDPCMAN 12/1/2008 12:58:13 AM I have done that. I tested both ways (with DHCP passthru enabled and disabled) and the only way it seems to want to work is if i turn off the new firewall :( "Anthony [MVP]" wrote: [Quoted Text] > Can you turn off the DHCP in the cable modem altogether? Then the old VPN > router should handle the request as it used to do, > Anthony, > http://www.airdesk.com > > > "ISDPCMAN" <ISDPCMAN[ at ]discussions.microsoft.com> wrote in message > news:81FDD5AD-0101-4694-81AB-F4F804636E16[ at ]microsoft.com... > > As indicated, I do have a route setup in the .8.5 gateway router to point > > any > > .9.x traffic to the .9.1 router. The VPN router still has its original > > configuration to go to the .9.1 router for 10.10.9.x traffic. > > > > DHCP passthrough is setup on both the VPN router and the .8.5 gateway. > >

Re: DHCP failes with 2nd router installed "Anthony [MVP]" <anthony[ at ]no-reply.com> 12/2/2008 6:56:24 AM Even with DHCP completely disabled on the new router? You would have to test with Wireshark and see what is happening to the DHCP request. Anthony, http://www.airdesk.com "ISDPCMAN" <ISDPCMAN[ at ]discussions.microsoft.com> wrote in message news:491383C5-E775-4672-A594-0F10F794FEC9[ at ]microsoft.com... [Quoted Text] > I have done that. I tested both ways (with DHCP passthru enabled and > disabled) and the only way it seems to want to work is if i turn off the > new > firewall :( > > "Anthony [MVP]" wrote: > >> Can you turn off the DHCP in the cable modem altogether? Then the old VPN >> router should handle the request as it used to do, >> Anthony, >> http://www.airdesk.com >> >> >> "ISDPCMAN" <ISDPCMAN[ at ]discussions.microsoft.com> wrote in message >> news:81FDD5AD-0101-4694-81AB-F4F804636E16[ at ]microsoft.com... >> > As indicated, I do have a route setup in the .8.5 gateway router to >> > point >> > any >> > .9.x traffic to the .9.1 router. The VPN router still has its original >> > configuration to go to the .9.1 router for 10.10.9.x traffic. >> > >> > DHCP passthrough is setup on both the VPN router and the .8.5 gateway. >> >>