misc/74140: ntpdate does not try all IPs for a host

[Kevin Thompson]

>Number:         74140
>Category:       misc
>Synopsis:       ntpdate does not try all IPs for a host
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Sat Nov 20 00:40:27 GMT 2004
>Closed-Date:
>Last-Modified:
>Originator:     Kevin Thompson
>Release:        5.3-STABLE
>Organization:
>Environment:
FreeBSD corrugated.csh.rit.edu 5.3-STABLE FreeBSD 5.3-STABLE #3: Sat Nov  6 18:39:15 EST 2004     antiduh at corrugated.csh.rit.edu:/usr/obj/usr/src/sys/CORRUGATED_5_3  i386
>Description:
When attempting to contact the specified server to adjust time, ntpdate seems to only try to connect to the first IP it comes up with for a given host.

An example:
I have a server, mcp.csh.rit.edu, that serves ntp for our services. In dns, we have a old IPv6 address for the machine registered, but the machine does not respond to this address. The machine, of course, responds on the IPv4 address.

When attempting to use 'ntpdate mcp.csh.rit.edu', the command fails because ntpdate cannot contact mcp's IPv6 address. 'ntpdate 129.21.60.9' works flawlessly.
>How-To-Repeat:
Create a multiple dns entries for a server, many of which the machine will not respond for, run ntpd on that machine and try to sync another machine with that server using 'ntpdate host' and then 'ntpdate <ipv4 address>'.

>Fix:
Attempt to contact all known IP addresses listed for the machine.
>Release-Note:
>Audit-Trail:
>Unformatted: