[nzlug] no dns with wvdial + paradise.net.nz in edubuntu 6.06

[Mark Foster]

>> ISPs of size (Xtra in particular) have suffered hard, because the DNS
>> servers used to host domain names were also the ones that client's used...
>> until they got so big that they had to split them off. Clients get
>> different DNS servers auto-assigned these days.  (Its relatively hard to
>> load-share DNS compared to say, MX or www traffic, when you have to
>> hard-specify IP addresses (and not hostnames) into a config.)
> DNS traffic is so lightweight that a ( correctly configured! ) server can handle a huuuge number of requests. Although it's no comparison, being a private company, the whole of DHL EMEA was run off 2 servers far less powerful than 386's and they permanently showed zero load, and minimal traffic.

A nice thought, but, well, I'm sure the engineers responsible for managing 
Xtra's DNS platform during say, the last 3-4 years, might dispute this 
generalisation somewhat. :)

Whilst in general, DNS queries are low load, theres plenty of ISPs out 
there that deliberately rig up their DNS servers such that a set of 
servers exist as caching servers for client use (allowing unlimited 
external queries from internal users) and a seperate set of servers exist 
as hosting servers (allowing unlimited locally-hosted responses from all 
users).

Has the added advantage of putting your local users in the same boat as 
every other user, when it comes to DNS changes and TTLs, etc etc.  Levels 
the playing field and means that you can't continue on oblivious to the 
fact that your local authoritive zones are infact being ignored by 
everyone due to a change in authoritive DNS servers for a given domain in 
registry... (ye gods the issues i've had in the past with this little 
issue!)

My main point being, you cannot assume that results for 'dig 
paradise.net.nz ns' provide the same IP addresses as are intended for 
customer use. Might be true - or might might.  Swap paradise.net.nz for 
any other ISP as required.

Mark.