IPCP, DNS & DHCP

[andrew.butterworth]

Is there anyway that a router configured with a Dialer Interface and PPP to pass the received (through IPCP) DNS Server IP addresses onto a DHCP Scope that supports the routers local Ethernet interface (SOHO environment). At the moment I have DNS Servers configured in the routers DHCP Scope, but if the ISP changes these is there anyway I can automate this so the new servers are added to the DHCP Scope?

I have had a dig on CCO but can't find anything, I have also had a quick play about with the router but can't see any obvious commands.

Thanks

Andy

[tepatel]

There is no way to automatically configure the dns servers negotiated ip address from isp in to local dhcp config. You have to do it manually.

Also i don't think that ISP changes DNS servers ip that often. Infact, you can use any public DNS servers ip address out there as static and dns activities should work fine.

[andrew.butterworth]

There a few other vendors that do this for the SOHO type products (linksys?) and I thought it wouldn't be that difficult to include this in the DHCP code would it?

Andy

[nikovcco]

why dont´t you enable the local dns server with "ip dns server + ip dns primary..." and put that in the dhcp scope? works fine for me here.

[jaregalado]

Hi,

I remember seeing an option called "import all" in DHCP config examples given in the BCRAN CCNP Student Guide. If I remember well, they're talking about an ADSL 827 router receiving IPCP config from the Service Provider and then transfering this parameters (DNS PRI, DNS Sec, Domain Name) via DHCP to the hosts in the LAN.

This particular Cisco document describes how to import DHCP options from a DHCP Server located elsewhere in the network, but I think it will work Ok for the PPP/IPCP situation.

http://www.cisco.com/en/US/tech/tk648/tk361/technologies_configuration_example09186a0080094a52.shtml

Best wishes.