On Wed, 2004-06-23 at 20:04, Eric "Shubes" wrote:
> Craig White wrote:
> Does anyone here know DHCP really well? I've got a (not pressing, yet) 
> question. I set up a (RH9) network (firewall/gateway/samba) server for a 
> local net, acting as a DHCP server. I "hard coded" the DNS addresses 
> from the ISP into the DHCP server configuration. I also "hard coded" the 
> IP info for the ethernet device going to the outside (DSL modem, has 
> DHCP capability, does NAT). How do I configure DHCP and devices so that 
> both the server (to the lan) side and the client (to the ISP) side are 
> dynamic? In other words, how does (can) the DHCP client side pass DSN 
> addresses to the DHCP server side (of the same box, two NIC cards)?
> (Hoping this makes sense)
-----
Actually, it leaves me a bit confused as to what you are trying to do.

A linux router/gateway device with 2 NIC's as you are suggesting should
be a client on the DSL side IF that is the desire of your ISP (Qwest or
???) but in no way should your DHCP server be listening or providing
service to anything but your internal LAN. 

on a Red Hat system...
# cat /etc/sysconfig/dhcpd
DHCPDARGS=eth0

would tell dhcpd to listen/configure to only consider the ip space of
the eth0 device. Pretty much the same as starting dhcpd server as...
/usr/bin/dhcpd eth0

# cat /etc/dhcpd.conf
ddns-update-style ad-hoc;
# Local Network
subnet 192.168.1.0 netmask 255.255.255.0 {
        ddns-updates on;
        option netbios-name-servers 192.168.1.1;
        option domain-name-servers 192.168.1.1 , 192.168.1.254;
        option domain-name "mydomain.com";
        option broadcast-address 192.168.1.255;
        option subnet-mask 255.255.255.0;
        option routers 192.168.1.254;
        ddns-domainname "mydomain.com";
        default-lease-time 86400;
        range 192.168.1.100 192.168.1.199;
        authoritative;
        }

means that I am running my own dns server (mostly caching) but any
addresses will do. There are probably scripts that can 're-write' this
on the fly based upon the dns server addresses supplied by ISP but
unless you are using Cox, they are not likely to change and even Cox
doesn't change them all that often. If your 'external' NIC is configured
as a dhcp client, then it will write the dns server addresses supplied
to it directly into /etc/resolv.conf UNLESS you put a parameter like
PEERDNS = no into your ifcfg-ethx.

Craig

---------------------------------------------------
PLUG-discuss mailing list - PLUG-discuss@lists.plug.phoenix.az.us
To subscribe, unsubscribe, or to change  you mail settings:
http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss