Caching only Nameserver?

[Barry Margolin]

In article <394db7cb.967851 at news.rv.extension.net>,
Patrick Buedi <buedi at gmx.net> wrote:
>On 15 Jun 2000 10:36:48 -0700, Barry Margolin <barmar at genuity.net>
>wrote:
>
>>>thought a caching only Server holds a database with all the IP <->
>>>names?? I think I made a mistake in my configuration, read different
>[...]
>>Named keeps the cache in memory.  Restarting named wipes its memory, so the
>>cache is gone.
>So my configuration seems to be correct :-)
>Say... does all Name Servers on the Internet work like this? Cache the
>data only in memory?

I think Cisco Network Registrar can keep its cache in a permanent
database.  But most servers on the Internet are either BIND or Microsoft
DNS, and they don't retain the cache across restarts.

>If (hypotetically) all the Name Server´s in the I-Net where rebootet
>at the same time... the request for a specific domain could take hours
>till it is resolved... then a nslookup request would run across the
>Internet till he finds the Server who holds the domain?

Looking up a name normally only involves 2-3 queries.  You start by asking
a root server, which refers you to the TLD servers, which refers you to the
2nd-level domain servers, which answer your question.  In the case of the
COM domain, several of the root servers are also TLD servers, so one step
can be skipped.  And after the first time you try to look something up in a
particular TLD, you have that TLD server list cached.

Even if all the name server around the Internet were rebooted, once they
came up you would be able to query them and they should respond normally.

-- 
Barry Margolin, barmar at genuity.net
Genuity, Burlington, MA
*** DON'T SEND TECHNICAL QUESTIONS DIRECTLY TO ME, post them to newsgroups.
Please DON'T copy followups to me -- I'll assume it wasn't posted to the group.