Types of IPv6 addresses
There are few types of addresses w need to know about. These are:
- Global Addresses – Unique, global addresses used on the Internet. They use the following prefix 2000::/3 ( Routable )
- Link Local Addresses – Used to communicate with hosts on the same physical or logical network. These addresses start with FE80::/10 ( Not Routable )
- Site Local Address – The equivalent of RFC1918 (private addresses) but they are being deprecated. They start with FEC0::/10 prefix.
- Multicast Address – Multicast replaces broadcast (along with unicast). The addresses use the following prefix: FF00::/8.
- Loopback Interface : ::1/128
- Unspecified : ::/128
- Unique Local :FECD::/7
- Embedded IPv4 : ::/80
The length of the prefix assigned to different organizations looks like this:
- Registries will be assigned /23
- ISP will be assigned /32
- Sites will be assigned /48
Since Broadcast isnt there anymore with ipv6 , neighbor discovery use ICMPv6 ( Multicast )
FF02::1 – All local hosts on the link.
FF02::2 – All local routers on the link
FF02::5 – Ospf Routers
FF02::6 – Ospf DRs
FF02::9 – RIP Routers
FF02::A – EIGRP Routers
FF02::1:2 – DHCP Server Relay Agents
and use these messages :
DAD – Duplicate Address Detection , checking the link-local .
NA – Neighbor Advertisements, Advertise itself to neighbors.
RS – Router Solicitation, getting info about local routers.
RA – Router Advertisements, advertising yourself as an active router.
NS – Neighbor Solicitation, for neighbor information.
Configuration on Cisco :
(config)#ipv6 unicast-routing ( enable ipv6 )
IPv6 Manual Address Assignment
ipv6 address fe08x:x:x:x::/X ( link local )
ipv6 address 2001:X:X:X::X/X ( Global )
or
(config)#ipv6 unicast-routing ( this command enable RS and RA messages )
(config)#interface #
(config-if)#ipv6 enable
(config-if)#ipv6 address autoconfig
Creating a General Prefix :
(config)# ipv6 general-prefix “short-cut name” “ipv6 address”
The general-prefix option can be used as an alias for any command requiring an IPv6 address, addressing, acl and more.
It can be used to renumbering too in case of ISP change etc …
Example :
(config)# ipv6 general-prefix GL 2001:db8:feed::/48 <– this create the alias GL
so if i want to configure an interface :
(config)# interface ethernet0/0
(config-if)# ipv6 address GL 0:0:0:88::1/64 ( the 0:0:0 represent the /48 )
show interface 0/0
…
2001:db8:cafe:88:1
Verification :
Show ipv6 interface ( interface )
Show ipv6 int brief
Show ipv6 neighbors
for easiest way to ping to test in the future you can map name for each ipv6 .
(config)#ipv6 host (hostname) (global address here )
