IPv6 interface identifier

The second part of an IPv6 unicast or anycast address is typically a 64-bit interface identifier used to identify a host’s network interface. A 64-bit interface ID is created by inserting the hex value of FFFE in the middle of the MAC address of the network card. Also, the 7th Bit in the first byte is flipped to a binary 1 (if the 7th bit is set to 0 it means that the MAC address is a burned-in MAC address). When this is done, the interface ID is commonly called the modified extended unique Read more [...]

IPv6 address prefixes

Here is a summary of the most common address prefixes in IPv6: Prerequisites for 200-301 200-301 is a single exam, consisting of about 120 questions. It covers a wide range of topics, such as routing and switching, security, wireless networking, and even some programming concepts. As with other Cisco certifications, you can take it at any of the Pearson VUE certification centers. The recommended training program that can be taken at a Cisco academy is called Implementing and Administering Cisco Solutions Read more [...]

IPv6 multicast addresses

Multicast addresses in IPv6 are similar to multicast addresses in IPv4. They are used to communicate with dynamic groupings of hosts, for example all routers on the link (one-to-many distribution).Here is a graphical representation of the IPv6 multicast packet:IPv6 multicast addresses start with FF00::/8. After the first 8 bits there are 4 bits which represent the flag fields that indicate the nature of specific multicast addresses. Next 4 bits indicate the scope of the IPv6 network for which the Read more [...]

Differences between IPv4 and IPv6

The following table summarizes the major differences between IPv4 and IPv6: FeatureIPv4IPv6Address length32 bits128 bitsAddress representation4 decimal numbers from 0-255 separated by periods8 groups of  4 hexadecimal digits separated by colonsAddress typesunicast, multicast, broadcastunicast, multicast, anycastPacket header20 bytes long40 bytes long, but simpler than IPv4 headerConfigurationmanual, DHCPmanual, DHCP, auto-configurationIPSec supportoptionalbuilt-in  Prerequisites for 200-301 200-301 Read more [...]


RIPng is an extension of RIP developed for support of IPv6. Here are some of its features:just like RIP for IPv4, it uses hop count as the metricsends updates every 30 secondsRIPng messages use the UDP port 521 and the multicast address of FF02::9 The configuration of RIPng is requires at least two steps:1. enable RIPng using the global configuration command ipv6 router rip tag. The tag is used to differentiate between multiple RIP processes. It does not have to be the same on all routers in Read more [...]

IPv6 link-local addresses

Link-local IPv6 addresses have a smaller scope as to how far they can travel: only within a network segment that a host is connected to. Routers will not forward packets destined to a link-local address to other links. A link-local IPv6 address must be assigned to every network interface on which the IPv6 protocol is enabled. A host can automatically derive its own link local IP address or the address can be manually configured.Link-local addresses have a prefix of FE80::/10. They are mostly used Read more [...]