Strange nis / services problem - any thoughts?
I just recently converted over to using nis to deliver my /etc/passwd
and /etc/group data on my home lan. All has been working fine with that
for a few weeks, so I decided last night to convert over to having my
workstation obtain /etc/services, /etc/protocols, /etc/ethers, and
/etc/rpc data from the nis server as well. I modified /etc/nsswitch
accordingling (by changing the entires for services, protocols, ether,
and rpc from "files" to "nis files").
Tonight, I booted up, and issued "sudo apt-get update" as I usually do -
and instead of retrieving the appropriate info, apt spit out a slew of
error messages being unable to connect to any of the deb mirrors I
usually use. At first, I thought the mirrors were broken, but realized
that several different mirrors were unlikely to _all_ be broken the same
way at the same time.
Thinking my mod to nsswitch.conf could have broken something, I edited
it and removed "nis" from the above databases, and retried the apt-get
update, and it worked fine. Further, I found that one of my standard
tricks to check network connectivity, telnetting to an smtp port on an
outside server, failed - when I tried "telnet smtp.foo.com smtp", I
couldn't get connected when nsswitch used nis for services, but could
connect when it only used files. Because the line reads 'services nis
files', I assume that nis must be returning bogus info for the service,
because if it just failed to return anything, then presumable the lookup
would go on to my local file which would give the right data.
I then wrote a quick program to call getservbyname with a specified
service parameter and print out the results, and found that I got back
the same data regardless of whether nssswitch specifies nis is to be
used or not. Finally, I can specify nis for ethers, rpc, and protocols
without breaking anything, but if I do for services, then apt, telnet,
etc are all broken.
I'm not sure what's going on here to cause this to happen. Any thoughts
appreciated!
Thanks.
nl
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