Gaurav Kansal Blog

Best Current Practices in for IPv6 Address Allocation This Best Practices document aims to provide IPv6 Address allocation guidelines that a network operator can follow while planning the IPv6  sub-netting  for its network (based on the issues faced and learning’s from IPv6 implementation in NKN and NIC network). Best Current Practice: 1. Sub-netting         IPv6 addresses generally written in Hex format. Each Hex number represents 4 bit, commonly known as nibble. A nibble boundary is a network mask that aligns on a 4-bit boundary. Sub-netting the v6 address at nibble boundary improves efficiency and make it easier to understand for humans* (Machine will anyway read it binary format  J ). Example of Nibble and non-Nibble Boundaries Sub-netting From the above example, we can clearly see that Sub-netting at the Nibble boundaries is easier to manage and do the sub-netting. * Condition may arise where you may have to

DIG is a command-line tool for querying DNS Name Server (similar to nslookup utility available in Windows and host utility). dig utility can be used for querying DNS about the host address (both A and AAAA), name server(NS), mail exchange(MX), Pointer Record(PTR), SOA (Start Of Authority) and others. DIG is a part of BIND software package ( BIND package is developed and managed by Internet Systems Consortium ISC). Usage Example :- 1. Ask for a host address :- dig nkn.in 2. Ask from a specific server :- dig nkn.in @8.8.8.8 ; <<>> DiG 9.8.5-P2 <<>> nkn.in @ 8.8.8.8 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 13527 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0 ;; QUESTION SECTION: ;nkn.in. IN A ;; ANSWER SECTION: nkn.in. 14103 IN A 164.100.56.206 ;; Query time: 171 msec ;; SERVER: 8.8.8.8#53 (8.8.8

DIG is a domain query tool and a part of BIND package of ISC. Using dig is very simple in Linux but is little bit tricky to use the same in Windows. I have tried to do the same and sharing you the steps which i follow for configuring the dig in my windows machine. How to install dig in Windows :- 1. Create a folder for dig (eg: C:\dig) 2. Download the latest version (currently which is 9.8.5-P2) of BIND software from  here  (ZIP format) 3. Extract the .zip file and copy the dig.* and *.dll files in the folder created in step 1 4. Add the folder in the Environment Variables path settings (Right click on My Computer --> click on Properties --> Advance System Settings --> Environmental Variables --> Path ) Use dig more efficiently (using .digrc) :- dig gives lot of information in its output which may not be useful in most of cases (and may be annoying for some of us). To cut short the dig output to show you only the answer section, you need to give lot of pa