Which of the following is valid IPv6 address?
The following list shows examples of valid IPv6 (Normal) addresses: 2001 : db8: 3333 : 4444 : 5555 : 6666 : 7777 : 8888. 2001 : db8 : 3333 : 4444 : CCCC : DDDD : EEEE : FFFF. : : (implies all 8 segments are zero)
Typically strings, that do *not* trepresent a valid IPv6 address have characters other than the hex-digits in it, or they consists of less than 8 blocks of hexdigits, or they have at least one block of hexdigits in it with more than 4 hex-digits, or they have more than one position in it, where 2 colons directly follow ...
Will IPv6 addresses run out eventually? In practical terms, no. There are 2^128 or 340 trillion, trillion, trillion IPv6 addresses, which is more than 100 times the number of atoms on the surface of the Earth. This will be more than sufficient to support trillions of Internet devices for the forseeable future.
G. Explanation: The addresses 255.1. 4.2 and fe80:2030:31:24 are not valid IPv6 addresses.
* :: is the IPv6 "unspecified address." It is a unicast address not assigned to any interface, and is used by a DHCP -dependent host prior to allocating a real IPv6 address. * 2001:0:42:3:ff::1 is a valid IP address, with the :: representing two segments (4 bytes) of compressed zeros.
Before jumping into details, there are a few key features IPv6 incorporates: IPv6 uses 128-bit (2128) addresses, allowing 3.4 x 1038 unique IP addresses. This is equal to 340 trillion trillion trillion IP addresses.
An IPv6 address is represented as eight groups of four hexadecimal digits, each group representing 16 bits The groups are separated by colons (:). An example of an IPv6 address is: 2001:0db8:85a3:0000:0000:8a2e:0370:7334.
- Unicast addresses identify a single interface.
- Anycast addresses identify a set of interfaces in such a way that a packet sent to an anycast address is delivered to a member of the set.
IP (version 4) addresses are 32-bit integers that can be expressed in hexadecimal notation. The more common format, known as dotted quad or dotted decimal, is x.x.x.x, where each x can be any value between 0 and 255. For example, 192.0. 2.146 is a valid IPv4 address.
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IPv6 Relative Network Sizes.
/128 | 1 IPv6 address | A network interface |
---|---|---|
/24 | 16,777,216 subscriber sites | 256 times larger than the minimum IPv6 allocation |
How many IPv6 addresses are in a 64?
So a /64 indicates that the first 64 bits of the 128-bit IPv6 address are fixed. The remaining bits (64 in this case) are flexible, and you can use all of them. This means that when your ISP gives you a /64 they are giving you 264 addresses (that is 18,446,744,073,709,551,616 addresses).
A 48 bit mask on an IPv6 address splits a 128 bit address into 65,536 (2^16) networks, each with 2^64 possible hosts.

The correct answer is option 2 i.e 128 bits. An IPv6 address has a size of 128 bits.
Which of the following are valid IPv6 addresses? An IPv6 IP address is a 128-bit address listed as eight 16-bit hexadecimal sections. Leading zeros can be omitted in each section. Therefore, 6384:1319:7700:7631:446A:5511:8940:2552 and 141:0:0:0:15:0:0:1 are both valid IPv6 addresses.
Specify IPv6 addresses by omitting leading zeros. For example, IPv6 address 1050:0000:0000:0000:0005:0600:300c:326b can be written as 1050:0:0:0:5:600:300c:326b . Double colon. Specify IPv6 addresses by using double colons ( :: ) in place of a series of zeros.
0.0 as a reserved, special-purpose address for "this host, this network." Its IPv6 equivalent is expressed as ::/0. Although 0.0. 0.0 is valid address syntax, a client device using it as a source IP address cannot communicate on a network. IPv4 address numbers start with 0.0.
255.255. 255.255 represents the local broadcast address, which is only propagated within the network. This broadcast data cannot cross routers by default. That is, it is a restricted broadcast address.
For example, IPv6 address 1050:0000:0000:0000:0005:0600:300c:326b can be written as 1050:0:0:0:5:600:300c:326b . Double colon. Specify IPv6 addresses by using double colons ( :: ) in place of a series of zeros. For example, IPv6 address ff06:0:0:0:0:0:0:c3 can be written as ff06::c3 .
Select IPv6 from the list of options on the left so that it is highlighted. To enable IPv6, the switch icon in the upper right corner needs to be set to ON and the Addresses pop-up underneath set to Automatic. To disable IPv6, slide the IPv6 setting to OFF. Click Apply.
That's a lot. To be exact, it's 340,282,366,920,938,463,463,374,607,431,768,211,456 (340 undecillion, 282 decillion, 366 nonillion, 920 octillion, 938 septillion, 463 sextillion, 463 quintillion, 374 quadrillion, 607 trillion, 431 billion, 768 million, 211 thousand and 456. Say that four times fast!)
Why do I have 3 IPv6 addresses?
You will get a different IPv6 address for each unique interface/MAC address. So your wifi and cellular will have two different ones. Once you VPN to a network, you will get a third IPv6.
site you'll need a larger allocation--e.g., /44 for up to 16 sites, /40 for up to 256 sites, /36 for up to 4,096 sites, and a /32 for up to 65,536 sites. allocations are usually tied to the duration of the contract for IPv6 connectivity.
This standard IPv6 chart shows that there are 512,000 possible /48 subnets that can be allocated out of a /29.
An IPv6 route consume four times more memory than IPv4 routes & it may not be desirable to update routers immediately. Therefore a /64 plan makes for better, more comprehensible route summarisation during the early phase of adoption by virtue of using a single netmask and easier to deploy summarisation.
Just as with IPv4, a single device's interface can have more than one address; with IPv6 there are more types of addresses and the same rule applies. There can be link-local, global unicast, and multicast addresses all assigned to the same interface.