Subject: Re: Local IP addresses changing
To: Erik E. Fair <fair@clock.org>
From: Andrew Brown <atatat@atatdot.net>
List: tech-net
Date: 08/25/2000 14:27:21
>Two things:
>
>1. NTP should get intimate enough with the BIND DNS code to get the 
>TTL along with the A RR, and should requery the name/address mapping 
>for all peers when their TTLs expire. The TTL is the maximum time 
>that such a mapping is guaranteed to be valid. This necessarily means 
>that NTP should be keeping peering relationships with host names 
>rather than host addresses...

using the resolver code isn't that hard.  i had to write an
asynchronous resolver some time ago, and a few parts of libresolv were
very helpful.

   res_init()
   res_randomid()
   res_mkquery()
   dn_expand()

it ought to be relatively trivial to add functions to ntpd that were
called gethostby{name,addr}() but that returned a slightly different
struct hostent (with the ttl intact) so that not much would have to
change.

>They have to be recoded so that they reinitialize themselves, as 
>appropriate. This can happen periodically, or because some error is 
>returned by the network code, or we come up with some event 
>notification system. Doesn't matter how it's done - we just have to 
>do it for all user level network code. Want an amusing case to think 
>about? Think about routed...

routed indeed!  unless i've completely misunderstood way too much,
simply listening on socket of type AF_ROUTE should enable one to
notice interfaces going up and down, no?

-- 
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