the problem was that the nameserver 192.168.184.250 did not have a PTR
record for it's own IP address.
Adding the record
250.184.168.192.in-addr.arpa. IN PTR ns.other.domain.
did the trick.
Using 'nslookup -d2' was useful as it let me see the queries and responses as they
were generated and received.
Thanks again.
John.
Original Post:
> Hi,
>
> Can anybody throw any light on a very weird DNS problem that I have?
>
> I have a machine (SPARC 5, Solaris 2.5.1 + Aug 97 patches) that is only a
> resolver:
>
> /etc/resolv.conf:
> domain net.foo.com
>
> nameserver 192.168.184.250
>
> (the name is wrong, the address is correct - we need the RFC1597
> addresses).
>
> This is the *ONLY* DNS setup on the machine. Period. It does not run
> primary or secondary for any other domain.
>
> Now, if I type:
>
> root# nslookup
> *** Can't find server name for address 192.168.184.250: Non-existent host/domain
> *** Default servers are not available
>
> and I dont know what this is trying to tell me.
> >
> If I change the resolv.conf file to, for instance,
>
> /etc/resolv.conf:
> domain domain.foo.com
>
> nameserver 154.32.109.18
>
> then:
>
> root# nslookup
> Default Server: res3.dns.uk.psi.net
> Address: 154.32.109.18
>
> >
>
> no problems at all.
>
> Neither of the machines used as nameservers above have entries in
> /etc/hosts and both *are* PINGable.
>
> My /etc/nsswitch.conf reads:
>
> host: files [notfound=CONTINUE] dns
>
>
> If I do a snoop(1m) of the network packets for the instance of nslookup
> that fails then only two packets are generated (I have listed these below).
> You can see that the DNS is trying to resolve something in the in-addr.arpa
> domain - obviously the IP address of the nameserver - but I dont know why
> it is failing.
>
> I thought I was good at this stuff ... ;)
>
> Any ideas, suggestions, questions, places to look are extremely welcome.
>
> Will summarize. Natch.
>
> Thank you all very much.
>
> John.
>
>
> SNOOP OUTPUT
>
>
> ETHER: ----- Ether Header -----
> ETHER:
> ETHER: Packet 1 arrived at 15:04:30.99
> ETHER: Packet size = 88 bytes
> ETHER: Destination = router.my.domain
> ETHER: Source = sun.my.domain
> ETHER: Ethertype = 0800 (IP)
> ETHER:
> IP: ----- IP Header -----
> IP:
> IP: Version = 4
> IP: Header length = 20 bytes
> IP: Type of service = 0x00
> IP: xxx. .... = 0 (precedence)
> IP: ...0 .... = normal delay
> IP: .... 0... = normal throughput
> IP: .... .0.. = normal reliability
> IP: Total length = 74 bytes
> IP: Identification = 7801
> IP: Flags = 0x4
> IP: .1.. .... = do not fragment
> IP: ..0. .... = last fragment
> IP: Fragment offset = 0 bytes
> IP: Time to live = 255 seconds/hops
> IP: Protocol = 17 (UDP)
> IP: Header checksum = 6ddb
> IP: Source address = A.B.C.D, sun-client
> IP: Destination address = W.X.Y.Z, ns.other.domain
> IP: No options
> IP:
> UDP: ----- UDP Header -----
> UDP:
> UDP: Source port = 32920
> UDP: Destination port = 53 (DNS)
> UDP: Length = 54
> UDP: Checksum = 37D7
> UDP:
> DNS: ----- DNS: -----
> DNS:
> DNS: "Y\256\1\0\0\1\0\0\0\0\0\0\003250\003184\003168\003192\7in-addr\4arpa\0\0\f\0\1"
> DNS:
>
>
> ETHER: ----- Ether Header -----
> ETHER:
> ETHER: Packet 2 arrived at 15:04:31.17
> ETHER: Packet size = 167 bytes
> ETHER: Destination = sun.my.domain
> ETHER: Source = router.my.domain
> ETHER: Ethertype = 0800 (IP)
> ETHER:
> IP: ----- IP Header -----
> IP:
> IP: Version = 4
> IP: Header length = 20 bytes
> IP: Type of service = 0x00
> IP: xxx. .... = 0 (precedence)
> IP: ...0 .... = normal delay
> IP: .... 0... = normal throughput
> IP: .... .0.. = normal reliability
> IP: Total length = 153 bytes
> IP: Identification = 53430
> IP: Flags = 0x0
> IP: .0.. .... = may fragment
> IP: ..0. .... = last fragment
> IP: Fragment offset = 0 bytes
> IP: Time to live = 62 seconds/hops
> IP: Protocol = 17 (UDP)
> IP: Header checksum = bc4f
> IP: Source address = W.X.Y.Z, ns.other.domain
> IP: Destination address = A.B.C.D, sun.my.domain
> IP: No options
> IP:
> UDP: ----- UDP Header -----
> UDP:
> UDP: Source port = 53
> UDP: Destination port = 32920
> UDP: Length = 133
> UDP: Checksum = 9519
> UDP:
> DNS: ----- DNS: -----
> DNS:
> DNS: "Y\256\205\203\0\1\0\0\0\1\0\0\003250\003184\003168\003192\7in-addr\4arpa\0\00\f\0\1\003168\003192\7in-ad"
>
--
\\|//
( @ @ )
+----oOO--(_)--OOo--------------------[John.Birtley@BAeSEMA.co.uk]-----+
| John Birtley, Unix System Administrator |
| BAeSEMA, Broomielaw, 1 Atlantic Quay, Glasgow, G2 4JE |
| Tel: +44 (141) 204-2737 Fax: +44 (141) 221-6435 |
+----------------------------------------------------------------------+
|Even if my views agree with BAeSEMA they are NOT the views of BAeSEMA.|
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