Linux/DNS: Difference between revisions

Latest revision as of 11:29, 19 August 2019

Ubuntu 18.04 show DNS settings

systemd-resolve --status

host (scripting)

dig (testing)

install

apt install dnsutils

Basic query

dig google.com

Query all record types

dig google.com ANY

Query specific DNS server

dig google.de @8.8.8.8

Reverse DNS lookup

dig -x 193.99.144.80

Trace DNS path

dig google.com +trace

nslookup

nslookup google.com
nslookup -query=ANY google.com

DNS entry

$TTL 86400
@ IN SOA ns1.first-ns.de. postmaster.robot.first-ns.de. (
     2000091604  ; Serial
     14400       ; Refresh
     1800        ; Retry
     604800      ; Expire
     86400  )    ; Minimum

@           IN NS    ns1.first-ns.de.
@           IN NS    robotns2.second-ns.de.
@           IN NS    robotns3.second-ns.com.

localhost   IN A     127.0.0.1
@           IN A     1.2.3.4
www         IN A     2.3.4.5
www         IN AAAA  2001:db8::1
mail        IN A     2.3.4.5

loopback    IN CNAME localhost
pop         IN CNAME www
smtp        IN CNAME www
relay       IN CNAME www
imap        IN CNAME www
ftp    3600 IN CNAME ftp.anderedomain.de.

@           IN MX 10 mail

technik     IN A     5.6.7.8
technik     IN MX 10 technik

@           IN TXT   "v=spf1 mx -all"

DNS entry types

ANY (all types)
A (Host address)
AAAA (IPv6 host address)
ALIAS (Auto resolved alias)
CNAME (Canonical name for an alias)
MX (Mail eXchange)
NS (Name Server)
PTR (Pointer)
SOA (Start Of Authority)

$TTL 86400
@ IN SOA ns1.first-ns.de. postmaster.robot.first-ns.de. (
2000091604  ; Serial
14400       ; Refresh
1800        ; Retry
604800      ; Expire
86400  )    ; Minimum

SRV (location of service)
TXT (Descriptive text)

@@ Line 1: / Line 1: @@
-== host ==
+== Ubuntu 18.04 show DNS settings ==
+<pre>
+systemd-resolve --status
+</pre>
+== host (scripting) ==
+== dig (testing) ==
+* install
+<pre>apt install dnsutils</pre>
+* Basic query
+<pre>dig google.com</pre>
+* Query all record types
+<pre>dig google.com ANY</pre>
+* Query specific DNS server
+<pre>dig google.de @8.8.8.8</pre>
+* Reverse DNS lookup
+<pre>dig -x 193.99.144.80</pre>
+* Trace DNS path
+<pre>dig google.com +trace</pre>
 == nslookup ==
+<pre>
+nslookup google.com
+nslookup -query=ANY google.com
+</pre>
+== DNS entry ==
+<pre>
+$TTL 86400
+@ IN SOA ns1.first-ns.de. postmaster.robot.first-ns.de. (
+     2000091604  ; Serial
+       ; Refresh
+        ; Retry
+      ; Expire
+  )    ; Minimum
+@           IN NS    ns1.first-ns.de.
+@           IN NS    robotns2.second-ns.de.
+@           IN NS    robotns3.second-ns.com.
+localhost   IN A     127.0.0.1
+@           IN A     1.2.3.4
+www         IN A     2.3.4.5
+www         IN AAAA  2001:db8::1
+mail        IN A     2.3.4.5
-== dig ==
+loopback    IN CNAME localhost
-<pre>apt install dnsutils</pre>
+pop         IN CNAME www
+smtp        IN CNAME www
+relay       IN CNAME www
+imap        IN CNAME www
+ftp    3600 IN CNAME ftp.anderedomain.de.
+@           IN MX 10 mail
+technik     IN A     5.6.7.8
+technik     IN MX 10 technik
+@           IN TXT   "v=spf1 mx -all"
+</pre>
+== DNS entry types ==
+* ANY (all types)
+* A (Host address)
+* AAAA (IPv6 host address)
+* ALIAS (Auto resolved alias)
+* CNAME (Canonical name for an alias)
+* MX (Mail eXchange)
+* NS (Name Server)
+* PTR (Pointer)
+* SOA (Start Of Authority)
+**
+<blockquote>
+<pre>
+$TTL 86400
+@ IN SOA ns1.first-ns.de. postmaster.robot.first-ns.de. (
+2000091604  ; Serial
+       ; Refresh
+        ; Retry
+      ; Expire
+  )    ; Minimum
+</pre>
+</blockquote>
+* SRV (location of service)
+* TXT (Descriptive text)