Re: having DHCP use name server from PPP connection?
Raj Kiran Grandhi wrote:
Daniel B. wrote:
Can dhcpd be configured to pass on (to DHCP clients on a local,
private (NATted) network) the DHCP server machine's current domain
name server addresses (given to the machine by PPP (etc.))?
What happens when your server's current name server changes before the
DHCP lease expires?
How about answering the question instead of bringing up other
concerns?
The name server specified in my PPP connections only changes when
my ISP decides to change something (on the scale of months).
Therefore, it's easy to set the lease length so the private-network
DHCP clients have an old name server setting for only a small
fraction of the time.
To answer your question directly: The same thing that happens any
time the current name server changes before the DHCP lease expires.
Right?
(That is, does it matter whether PPP updates the name server in
/etc/resolv.conf automatically or one edits manually? Whether
that's manual or automated, if the DHCP server configuration isn't
updated, then certainly the DHCP clients will be out of date. If
the server configuration _is_ updated, then if clients don't update
their leases, then they're still out of date (again, whether the
update is manual or automatic).
The only way client would get updated is if DHCP has some kind of
lease revocation, and, again, is doesn't seem to matter whether
the update is manual or automatic.)
I see how to hard-code name servers in /etc/dhcpd.conf with the
domain-name-servers statement.
However, I don't yet see how to have dhcpd report whichever name
servers are listed in /etc/resolve.conf (put there by PPP's
/etc/dhcpd.conf).
(What does dhcpd give to clients if there is no domain-name-servers
statement? The documentation I've seen (dhcpd, dhcpd.conf manual
pages; Sarge version) doesn't seem to say.)
It probably does not give anything.
Does anyone know of documentation that specifies what happens?
One possible solution to your problem is to run one of the several
caching name servers like pdnsd or dnsmasq on your DHCP server and pass
on your DHCP servers lan IP as the DNS server IP to the clients.
I was hoping to avoid messing with a DNS server, but, yes, that's
an option.
Thanks,
Daniel
--
Daniel B.
dsb@smart.net
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