cisco ccna book 2020

cisco ccna book 2020.xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx (where X is a hexadecimal bit). This representation is often referred to as the wordcharacter string representation. As mentioned in Chapter 3, the hexadecimal bits take values in the range 0.F. Here are some key points about IPv6 addresses.. The hexadecimal bit value A.F can be either uppercase or lowercase. . The zeros at the beginning of each section can be omitted; for example, in a section, you can enter 0012,or 12, which is correct both ways. . In an IPv6 address, if there are multiple contiguous parts that are all zeros, you can use two colons (::) to indicate them. For example.0:0:0:0:0:0:0:0:5 can be represented as :5, and 2000:C67:0:0:8888:9999:1111:0 can be represented as 2000:C67::8888:9999:lllll:0o However, this can only be done once in the same address: 2000::C67::891::00 is illegal because the :: appears occurs twice. This restriction exists because if there are multiple ::, it will be impossible to determine how many all-zero parts are represented by each ::.. Unspecified addresses that are all-zero are represented as ::.Keep in mind the format of an IPv6 address: it contains 8 parts of 4 hexadecimal bits each (16 binary bits). In an IPv6 address, if there are multiple contiguous parts that are all zeros, you can represent them as two colons (::), but you can only do this once in the same address: address 2000::C67::891::00 is illegal because :: appears twice in it.23.2.2 IPv6 Address TypesAs described in Chapter 6, there are various types of IPv4 addresses: unicast addresses, broadcast addresses, multicast addresses, addresses used for research, private addresses, and so on. There are also different types of IPv6 addresses, of which the following are the three main types.. Anycast: completely different from IPv4 broadcast addresses, which can represent multiple interfaces, but traffic using it is sent only to the nearest one. These addresses come from the unicast address space but can represent multiple devices. such as multiple default gateways. For example, by using an anycast address as the default gateway address, it allows user devices to know only one address and eliminates the need to configure gateway redundancy protocols such as HSRP or VRRP.. Multicast: similar to an IPv4 multicast address. . Unicast: indicates a single interface.