got two questions on DNS

[Gareth Bromley]

Bovine Unit #243 wrote:

> 1. I connect to my ISP via dial-up PPP modem (56K kind). Everytime
> after successful connection, my DNS server seems to have a lag time of
> 1 to 2 minutes before it forwards DNS query to my ISP's DNS server. Of
> course, after the initial lag, everything would be working as normal.
> Is there any way to speed-up whatever's going on?

Looking through the Bind 'Bible' v3 Chapter 15.5 includes a number of tips
for Bind setup and conf in dial-up environments.

> 2. It looks like my DNS is trying to broadcast its presence to the
> outside -- which is a no-no since this is 192.168.x.x, I believe. At
> least my ISP is doing it correctly by denying the request. But it sure
> bugs the heck out of me when the error gets logged. Anyway to turn
> this mechanism off?

Using:
options { query-source Valid.IP.Here port *;};

In your named.conf will force Bind to use your valid Internet IP if it
exists (This will/may be a problem on DHCP interfaces). Other ways round
this are to use NAT to hide the DNS server(s) IP address to a real one
(Cisco IOS does this very well, as do most firewalls e.g. Linux Chains)

Hope this helps,

--Gareth