🟨IPv6
Last updated
Last updated
The presence of an inet6 entry doesn’t automatically mean the computer is accessible from external addresses.
An Ipv6 address uses 128 bits as opposed to 32 bits in IPv4.
IPv6 addresses are written using hexadecimal, as opposed to dotted decimal in IPv4
Because an hexadecimal number uses 4 bits this means that an IPv6 address consists of 32 hexadecimal numbers.
group1:group2: ……etc…. :group8Here is an IPv6 address example:
Broadcast addresses are no longer used in IPv6, replaced with multicast addresses. If an IPv6 host wants to send traffic to all the hosts on the LAN, which would have formerly used a broadcast IPv4 address and an FF:FF:FF:FF:FF:FF MAC address, the host uses the FF02::1 IPv6 address with a destination MAC address of 33:33:00:00:00:01
FE80::/10 – Link local (analogous to IPv4 169.254.0.0/16 address space defined in RFC 5735 and RFC 3927)
FC00::/7 – Unique local address (analogous to IPv4 192.168.0.0/16, 10.0.0.0/8, and 172.16.0.0/12 address space defined in RFC 1918)
FF00::/8 – Multicast IPv6 traffic
FF02::1/64 – All nodes multicast address, replacing IPv4 broadcast address 255.255.255.255
2000::/16 – Used for stateless autoconfiguration of IPv6 addresses using the EUI 64 expansion method, leveraging the client MAC address
2001::/16 – Internet-wide global allocation of IPv6 address space to regional registries (analogous to the former IPv4 unique organizational address space allocations, such as 4.0.0.0/8, 64.24.0.0/16, and so on)
2001:db8::/32 – Used for documentation purposes
Because of the length of IPv6 addresses various shortening techniques are employed.
The main technique being to omit repetitive 0’s as shown in the example above.
In IPv4 an address is split into two components a network component and a node component.
This was done initially using Address classes and later using subnet masking.
In IPv6 we do the same. The first step is to split the address into two parts.
The address is split into 2 64 bit segments the top 64 bits is the network part and the lower 64 bits the node part:
IPv6 addresses have three types:
Global Unicast Address –Scope Internet- routed on Internet
Unique Local — Scope Internal Network or VPN internally routable, but Not routed on Internet
Link Local – Scope network link- Not Routed internally or externally.
The IPv6 loopback address is ::1. You can ping it as follows:
