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What is IP address? How many types of IP address?

An IP address (Internet Protocol address) is a unique address that some electronic devices use to identify and communicate with each other on a computer network utilizing the Internet Protocol standard (IP). In simpler terms, IP address is a computer address.

There are mainly two type IP addresses: IPv4 and IPv6. IPv4 (Internet Protocol version 4) is widely used on the Internet, and it uses 32 bits to represent an address. IPv6 (Internet Protocol version 6), the successor of IPv4, makes use of 128 bits to represent an address instead of 32 bits. IPv6 has enough room for 3.4×1038 unique addresses.

What is DNS Zone file? What kind zone types are being used by .hk?

These are the files that contain the list of all the hosts in your domain, and their corresponding IP address. There are 13 types of zone file, which are .com.hk, .edu.hk, .org.hk, .idv.hk, .hk, .gov.hk, .net.hk, .公司.hk, .網絡.hk, .組織.hk, .教育.hk, .政府.hk, .個人.hk.

What is IPv6?

Each computer on the Internet is assigned a unique number called the IP (Internet Protocol) address. The current addressing scheme for IP addresses is called IPv4 (IP address version 4). IPv4 is 32-bit long (consisting of four 8-bit numbers separated by dots). It is expected that IPv4 addresses currently use on every device connected to the Internet would eventually run out or with very limited supply. Therefore, a new addressing scheme called IPv6 (IP address version 6) has been developed. An IPv6 address is 128 bits long (consisting of eight 16-bit numbers separated by colons).

What are the differences between IPv4 and IPv6?

Typical IPv4 IP address: – Four groups separated by (.). Each group consists of a number ranging from 1 to 256. In theory, IPv4 can address up to 4,294,967,296 devices.

Typical IPv6 IP address:
2001:0db8:85a3:0000:0000:8a2e:0370:7334 – IPv6 addresses are normally written as eight groups of four hexadecimal (0-9, a-f) digits, where each group is separated by a colon (:).IPv6 can address up to 3.403 × 1038 unique addresses.

What does IPv6 looks like in the DNS?

Take ns5.hkirc.hk as an example. When you normally look up DNS IP in IPv4 using the dig command, the IPv4 result for ns5.hkirc.hk is shown as: ns5.hkirc.hk. 300 IN A We can notice the single “A” in the answer, which indicates it is an IPv4 address.

Doing the same with a domain name which have IPv6 address, the answer for ns2.cuhk.edu.hk: ns2.cuhk.edu.hk. 14400 IN AAAA 2405:3000:3:60::21.
The “AAAA” in the result means that this is an IPv6 address.

What service does HKIRC offer for IPv6?

HKIRC has added the capability to register Domain Name with IPv6 addresses as name servers. HKIRC DNS server can now cater for both IPv4 address and IPv6 address, even though you are using existing IPv4 network. The clients do not need to have an IPv6 network, but still can enjoy this service.

What are the changes to the existing HKIRC panels for IPv6?

There is no difference in the appearance of the HKIRC IPv6 compatible panels. The only changes are the IP entry fields and display in the panel, which now support IPv6 notation as well as new address length for IPv6. Also, additional checks are added to check for valid IPv6 format in all entry fields.