passing DNS server addresses through DHCP?

ocicat002 · ‎02-22-2008

I'm setting up NAT & DHCP (both as a DHCP client & DHCP server) on a 2621. Since the DNS server address(es) are received on the router's interface configured as a DHCP client, is there a way to pass these (possibly dynamic) address(es) on the internal network clients? What I see in the DHCP server functionality is that the option specifying what DNS server(s) are passed on to clients is hard coded. If hard coding the option is my only choice, do I have any guarantee that the ISP will always use the same IP address(es) for its DNS servers?

Any insight would be appreciated.

Danilo Dy · ‎02-22-2008

Hi,

DNS don't change IP Address as often as its administrator blink their eyes :)

Some DNS doesn't have restriction of who should use them for recursive query. You can actually use other ISP DNS. But for sanity, use your ISP DNS for guaranteed recursive query.

Regards,

Dandy

ghostswitch · ‎02-22-2008

Thats exactly what the 'import all' command is for.

In your DHCP server, if you supply the command 'import all', it will seek the DHCP information that was given to it on the interface that has "ip address dhcp". It will store the information like DNS into your DHCP server, and then send that out to all devices receiving DHCP addresses from your server.