trussing nslookup

[John Hascall]

They are nameserver queries, from "man nslookup":

  server domain

  lserver domain
      Change the default server to domain.  lserver uses the initial server
      to look up information about domain, while server uses the current
      default server.  If an authoritative answer cannot be found, the names
      of servers that might have the answer are returned.

John


> Good morning.
> 
> I sent this yesterday but I didn't see it come thru, so I'm resending it.  Pa
rdon me if you've gotten duplicates.
> 
> truss of an interactive nslookup shows:
> 
> sendto(3, "DC k01\0\001\0\0\0\0\0\0".., 45, 0, 0xEFFDF568, 16) = 45
> poll(0xEFFDD230, 1, 5000)                       = 1
> recvfrom(3, "DC k8580\001\001\002\0\0".., 65536, 0, 0xEFFDF2B8, 0xEFFDF2C8) =
 13
> 8
> 
> This is when I use "server" to switch name server.  I don't know how to inter
pret the stuff that comes after "DC", can anyone help?
> 
> 
> I am on a box with named listening on one interface.  If that IP address is i
n /etc/resolv.conf, nslookup starts up fine.  However if I take that out of res
olv.conf, and use "server" in interactive nslookup to switch to that interface,
 nslookup hangs.  the truss looks like the above, there's a sendto(), a bunch o
f poll() that waits for a long time and then sleeps, but no recvfrom().  What c
ould happen to cause this?  Note that I am ON the box, so routing and traffic a
re not issues here.  Also, other hosts can use this interface just fine.  debug
1 of named on that interface looks quite normal.
> 
> Here's the truss of the misbehavior:
> 
> sendto(3, "DC l01\0\001\0\0\0\0\0\0".., 45, 0, 0xEFFDF568, 16) = 45
> poll(0xEFFDD230, 1, 5000)       (sleeping...)
> poll(0xEFFDD230, 1, 5000)                       = 0
> sendto(3, "DC l01\0\001\0\0\0\0\0\0".., 45, 0, 0xEFFDF568, 16) = 45
> poll(0xEFFDD230, 1, 10000)      (sleeping...)
> .
> .
> .[more of the same]
> 
> 
> 
> QCT
>