Subject: Re: Local IP addresses changing
To: Erik E. Fair <>
From: Don Lewis <>
List: tech-net
Date: 08/28/2000 06:52:17
On Aug 25, 11:00am, "Erik E. Fair" wrote:
} Subject: Re: Local IP addresses changing
} At 9:56 -0700 8/25/00, Andrew Brown wrote:

} >im(ns?)ho, ntpd should *also* periodically re-lookup the addresses for
} >hostnames that are its peers/servers.  i have had several annoying
} >situations where a host's address changed, the ntp.conf was correct on
} >a client/peer, and the host's time slowly drifted *anyway*.  ntpd just
} >needs to be restarted, but it's a pain.
} 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...

Recent versions of squid have an internal host name to IP address cache
that works this way.  It also does asynchronous lookups to avoid blocking
the entire process.