Differences

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--- networking:dns [2022/11/07 17:09] – oscar
+++ networking:dns [2023/08/26 07:01] (current) – oscar
@@ Line 5: / Line 5: @@
 ===== Querying DNS services =====
 Using dig command you can query DNS name servers for your DNS lookup related tasks. Dig stands for domain information groper.
-=== Simple query ===
+==== Simple query ====
 Standard query using the default DNS server configured on your system
 <code>
@@ Line 36: / Line 36: @@
   * **ADDITIONAL SECTION**: This displays the ip address of the name servers listed in the AUTHORITY SECTION.
   * **Stats section** at the bottom displays few dig command statistics including how much time it took to execute this query
-=== Use specific DNS server ===
+==== Use specific DNS server ====
 By default dig uses the DNS servers defined in your **/etc/resolv.conf** file. If you like to use a different DNS server to perform the query, specify it in the command line as **@dnsserver**.
-=== Short Output Using dig +short ===
+For example use directly the name server of TransIP (ns0.transip.net):
+  dig +short TXT @ns0.transip.net. oscardegroot.nl
+==== Short Output Using dig +short ====
 To view just the ip-address of a web site (i.e the A record), use the short form option as shown below.
 <code>
@@ Line 45: / Line 47: @@
 .86.60.198
 </code>
-=== Limit output to specific section ===
+==== Limit output to specific section ====
 The response can be limited to any of the sections. E.g. the next only displays the ANSWER SECTION.
 <code>
@@ Line 54: / Line 56: @@
 oscardegroot.nl.        13296   IN      A       83.86.60.198
 </code>
-=== Query Record types ===
+==== Query Record types ====
 With the -t option you can select a specific record type. This is one of: **a, any, mx, ns, soa, hinfo, axfr, txt**. The default is: a. Be aware that not all DNS servers have copies of all the records locally. So if this query return incomplete info, use a different DNS server.
 <code>
@@ Line 80: / Line 82: @@
 oscardegroot.nl.        300     IN      RRSIG   NSEC3PARAM 7 2 300 20210401000000 20210311000000 18644 oscardegroot.nl. acpYiIwzeUyrL  AsXeTYejnwOmFaDzW6ArA+OZUMbUZrQB9N/Mb5TB03I 8tUSa3wowD/noOepnAbE3A0Q+/gfsDNxZ4wuYmaPRPQ96OD9GJSJbhcS 5Bbd+QX0UOMKvRyEAQWPmbyXcOyLxx6a  3xgIjboeecAfb3oFZiPUdHT+ RyM=
 </code>
-=== DNS Reverse Look-up ===
+==== DNS Reverse Look-up ====
 To perform a DNS reverse look up using the ip-address using dig -x as shown below. For example, if you just have an external ip-address and would like to know the website that belongs to it, do the following.
 <code>
@@ Line 92: / Line 94: @@
 </code>
 ===== Monitor DNS requests =====
+<code>
+tcpdump -i wlan0 -n -s 0 port 53 | grep fdxx:xxx:xxxx:xxxx:xxxx:xxxx:xxx:xx
+</code>
 <code>
 script -q -c "sudo tcpdump -l port 53 2>/dev/null | grep --line-buffered ' A? ' | cut -d' ' -f8" | tee dns.log
 </code>