HP-UX IP Address and Client Management Administrator's Guide HP-UX 11i v2, HP-UX 11i v3

The response was sent back to host 15.19.10.14 on port 4258.
Example 2: Retransmissions
The next example shows a successful lookup that involves retransmissions. Retransmissions take
place from the resolver and the name server. The resolver retransmits to the local name server,
and the local name server retransmits to remote name servers during the process of looking up
a name. When the local server receives the resolver retransmissions, it discards them as duplicates
if it is still processing the first request.
datagram from 15.19.10.14 port 4253, fd 6,
len 41 req: nlookup(cucard.med.columbia.edu) id 1 type=1 req: found
‘cucard.med.columbia.edu’ as ‘edu’ (cname=0)
forw: forw -> 128.9.0.107 6 (53) nsid=17 id=1 1478ms retry 4 sec
datagram from 128.9.0.107 port 53, fd 6, len 212 resp: nlookup(cucard.med.columbia.edu)
type=1 resp: found ‘cucard.med.columbia.edu’ as ‘columbia.edu’
(cname=0) resp: forw -> 128.59.16.1 6 (53) nsid=18 id=1 0ms datagram
from 15.19.10.14 port 4253, fd 6, len 41 req: nlookup(cucard.med.columbia.edu)
id 1 type=1 req: found ‘cucard.med.columbia.edu’ as ‘columbia.edu’
(cname=0) resend(addr=1 n=0) -> 128.59.32.1 6 (53) nsid=18 id=1 0ms
resend(addr=2 n=0) -> 128.59.40.130 6 (53) nsid=18 id=1 0ms datagram
from 15.19.10.14 port 4253, fd 6, len 41 req: nlookup(cucard.med.columbia.edu)
id 1 type=1 req: found ‘cucard.med.columbia.edu’ as ‘columbia.edu’
(cname=0) resend(addr=3 n=0) -> 128.103.1.1 6 (53) nsid=18 id=1 764ms
datagram from 128.103.1.1 port 53, fd 6, len 57 send_msg -> 15.19.10.14
(UDP 7 4253) ID=1
Following are detailed explanations of certain lines from this example.
req: nlookup(cucard.med.columbia.edu) id 1
type=1
This message is logged from the routine that handles requests. The following shows the name
looked up, the packet ID (used to determine duplicate requests), and the type (as defined in
/usr/include/arpa/nameser.h). Type 1 is an address query.
resend(addr=1 n=0) -> 128.59.32.1 6 (53) nsid=18
id=1 0ms
Because no response is received from 128.59.16.1, the query with nsid 18 is resent to other
servers.
datagram from 15.19.10.14 port 4253, fd 6,
len 41 req: nlookup(cucard.med.columbia.edu) id 1 type=1
This is received from the same IP address and port and has the same length and ID as the
preceding datagram. It is a duplicate and thus forw discards it. These two lines are repeated
three times throughout the trace. The queries came from the same IP address and port, and have
the same ID and length in each case. Thus, these are all the same query. The resolver sends the
query three times because the name server did not respond. The name server detects that the
second and third are duplicates and discards them because the duplicates did not get to the forw
line.
Name Server Statistics
The name server keeps track of various statistics. You can print these statistics to the file
/var/tmp/named.stats by issuing the following command:
/usr/sbin/sig_named stats
Statistics are appended to the file. The statistics look similar to this:
time since boot (secs)1273431
time since reset (secs)29802
input packets326031
output packets327165
queries284353
iqueries0
Troubleshooting the BIND Name Server 97