nslookup CMD
1. nslookup CMD
_____________________
query name servers interactively
Nslookup is a program to query Internet
domain name servers.
Nslookup has two modes: interactive and non-interactive.
Interactive mode allows the user to query
name servers for
information about various hosts and
domains or to print a
list of hosts in a domain. Non-interactive
mode is used to
print just the name and requested
information for a host or
domain.
Interactive mode is entered in the
following cases:
1. when no arguments are given (the
default name server will
be used)
2. when the first argument is a hyphen (-)
and the second
argument is the host name or Internet
address of a name
server.
Non-interactive mode is used when the name
or Internet
address of the host to be looked up is
given as the first
argument. The optional second argument
specifies the host
name or address of a name server.
Options can also be specified on the
command line if they
precede the arguments and are prefixed
with a hyphen. For
example, to change the default query type
to host
information, and the initial timeout to 10
seconds, type:
2. Name Service Lookup CMD(s)
__________________________________
- dig
- host
- nslookup
(1). dig CMD
dig (domain information groper) is a
flexible tool for
interrogating DNS name servers. It
performs DNS lookups and
displays the answers that are returned
from the name
server(s) that were queried. Most DNS
administrators use dig
to troubleshoot DNS problems because of
its flexibility,
ease of use and clarity of output. Other
lookup tools tend
to have less functionality than dig.
Although dig is normally used with
command-line arguments,
it also has a batch mode of operation for
reading lookup
requests from a file. A brief summary of
its command-line
arguments and options is printed when the
-h option is
given. Unlike earlier versions, the BIND9
implementation of
dig allows multiple lookups to be issued
from the command
line.
Unless it is told to query a specific name
server, dig will
try each of the servers listed in
/etc/resolv.conf.
When no command line arguments or options
are given, will
perform an NS query for "." (the
root).
It is possible to set per-user defaults for
dig via
${HOME}/.digrc. This file is read and any
options in it are
applied before the command line arguments.
# dig www.daum.net
; <<>> DiG 8.3
<<>> www.daum.net
;; res options: init recurs
defnam dnsrch
;; got answer:
;; ->>HEADER<<-
opcode: QUERY, status: NOERROR, id: 2
;; flags: qr rd ra; QUERY: 1,
ANSWER: 9, AUTHORITY: 9, ADDITIONAL: 9
;; QUERY SECTION:
;; www.daum.net, type = A, class = IN
;; ANSWER SECTION:
www.daum.net. 3h47m46s IN CNAME daumtop.daum.akadns.net.
daumtop.daum.akadns.net. 2m58s IN A
211.115.77.211
daumtop.daum.akadns.net. 2m58s IN A
211.115.77.212
daumtop.daum.akadns.net. 2m58s IN A
211.115.77.214
daumtop.daum.akadns.net. 2m58s IN A
211.32.117.30
daumtop.daum.akadns.net. 2m58s IN A
211.115.77.213
daumtop.daum.akadns.net. 2m58s IN A
222.231.51.40
daumtop.daum.akadns.net. 2m58s IN A
211.115.115.211
daumtop.daum.akadns.net. 2m58s IN A
222.231.51.78
;; AUTHORITY SECTION:
akadns.net. 21h47m45s IN NS eur1.akadns.net.
akadns.net. 21h47m45s IN NS za.akadns.org.
akadns.net. 21h47m45s IN NS zd.akadns.org.
akadns.net. 21h47m45s IN NS use4.akadns.net.
akadns.net. 21h47m45s IN NS zc.akadns.org.
akadns.net. 21h47m45s IN NS usw2.akadns.net.
akadns.net. 21h47m45s IN NS asia9.akadns.net.
akadns.net. 21h47m45s IN NS use3.akadns.net.
akadns.net. 21h47m45s IN NS zb.akadns.org.
;; ADDITIONAL SECTION:
asia9.akadns.net. 1d23h48m18s IN A 220.73.220.4
eur1.akadns.net. 1d23h57m54s IN A 213.254.204.197
use3.akadns.net. 1d23h34m19s IN A 204.2.178.133
use4.akadns.net. 1h42m11s IN A
208.44.108.137
usw2.akadns.net. 1d49m46s IN A
63.209.3.132
za.akadns.org. 21h47m45s IN A
195.219.3.169
zb.akadns.org. 21h47m45s IN A
206.132.100.105
zc.akadns.org. 21h47m45s IN A
124.211.40.4
zd.akadns.org. 21h47m45s IN A
63.209.3.132
;; Total query time: 14 msec
;; FROM: solaris254 to SERVER:
default -- 168.126.63.1
;; WHEN: Wed Mar 5 13:43:52 2008
;; MSG SIZE sent: 30
rcvd: 510
[참고]
/root/SERVER/DNS/Reference/dig_활용방법_가이드.pdf
(2). host
host is a simple utility for performing
DNS lookups. It is
normally used to convert names to IP
addresses and vice
versa. When no arguments or options are
given, host prints a
short summary of its command line
arguments and options.
name is the domain name that is
to be looked up. It can also
be a dotted-decimal IPv4 address or a
colon-delimited IPv6
address, in which case host will by
default perform a
reverse lookup for that address. server is an optional
argument which is either the name or IP
address of the name
server that host should query instead of
the server or
servers listed in /etc/resolv.conf.
# host www.daum.net
(3). nslookup
자세한 내용은 "4. nslookup 사용법"를
참고한다.
# nslookup www.daum.net
3. Debugging for DNS
______________________
DNS 서버 설정이 이상이 있는 경우 디버깅하는 방법은
(a)nslookup 명령어를 사용하는 방
법, (b) /var/adm/messages 파일을 활용하는
방법, (c)signal을 사용하는 방법등이 있다.
■ nslookup 명령어를 사용하는 경우
■ /var/adm/messages & SIGHUP
사용하는 경우
■ 시그널 (SIGINT, SIGUSR1) 사용하는 경우
[EX1] nslookup 명령어를 사용하는 방법
# nslookup
> server 172.16.8.XXX (자신의 DNS 서버 지정)
> set
q=NS
> solarisXXX.example.com (자신의 도메인 지정)
> set
q=MX
> solarisXXX.example.com (자신의 메일 서버 도메인 지정)
> set
q=A
> www.solarisXXX.example.com (자신의 웹서버 도메인 지정)
[EX2] /var/adm/messages 파일과
signal(SIGHUP) 사용하는 경우
<TERM1> 관리자 윈도우 1
# tail -f
/var/adm/messages (# mlog)
..... (중략) .....
Jul 1 16:26:37 solaris254 named[189]: [ID 295310
daemon.notice] reloading nameserver
Jul 1 16:26:37 solaris254 named[189]: [ID 295310
daemon.notice] Ready to answer queries.
<TERM2> 관리자 윈도우 2
# pkill -HUP
in.named
[EX3] 다른 시그널을 사용하는 경우
# pkill -INT
in.named
# cat
/var/named/named_dump.db
.... (내용 생략).....
# pkill -USR1
in.named (Debug Mode ON)
# cat
/var/named/named.run
-----------------------------------------------------------------------
Debug level 1
Version = in.named BIND 8.3.3
Thu Jun 16 08:11:42 PDT 2005
Generic Patch-5.9-June 2005
conffile = /etc/named.conf
datagram from
[172.16.8.203].32967, fd 23, len 17
req: nlookup() id 11692 type=2
class=1
req: missed '' as '' (cname=0)
ns_req: answer ->
[172.16.8.203].32967 fd=23 id=11692 size=60 rc=0
prime_cache: priming = 0, root =
0
-----------------------------------------------------------------------
# pkill -USR2 in.named (Debug
Mode OFF)
4. nslookup 사용법
____________________
(1). How to using the nslookup
CMDs
- Non-interractive Mode(비 대화형 모드 실행)
- Interractive Mode(대화형 모드 실행)
EX)
Interractive/Non-interractive Mode
# nslookup www.daum.net
# nslookup
> www.daum.net
(2). nslookup CMD EXAMPLE
(2-1). 비 대화형 모드(Non-interractive Mode) 실행
# nslookup
-query=NS solarisXXX.example.com
# nslookup -q=A
ns.solarisXXX.example.com
# nslookup -q=MX
solarisXXX.example.com
# nslookup -q=PTR
172.16.8.XXX
(2-2). 대화형 모드(Interractive Mode) 실행
# nslookup
> test.solarisXXX.example.com
> 172.16.8.XXX
> ls
solarisXXX.example.com
(1st Style)
> ls -a
www.solarisXXX.example.com (a: alias)
> ls
-d solarisXXX.example.com (d:
detail)
> ls -t MX
solarisXXX.example.com
> ls -t A
www.solarisXXX.example.com
> ls -t PTR 172.16.8.XXX
> ls -t NS
solarisXXX.example.com
(2nd Style)
> set type=MX
> solaris254.example.com
> set type=A
> www.solaris254.example.com
> set type=PTR
> 172.16.8.254
> set type=NS
> solaris254.example.com
(3rd Style)
> set
q=NS (Name Server)
> solarisXXX.example.com
> set
q=MX (Mail Exchange)
> solarisXXX.example.com
> set
q=A (Address)
>
www.solarisXXX.example.com
> set
q=PTR (Address Pointer)
> 172.16.8.XXX
> server
168.126.63.1
> set
q=NS
> kornet.net //도메인 네임
> set
q=MX
> kornet.net //도에인 네임
> set
q=A //adress
> www.kornet.net
> set
q=PTR
> 211.216.50.150
> exit
Rss Feed