IP Addressing¶
IPv4¶
0.0.0.0/8 Current network (only valid as source address) RFC 6890
10.0.0.0/8 Private network RFC 1918
127.0.0.0/8 Loopback RFC 6890
169.254.0.0/16 Link-local RFC 3927
172.16.0.0/12 Private network RFC 1918
192.88.99.0/24 IPv6 to IPv4 relay RFC 3068
192.168.0.0/16 Private network RFC 1918
224.0.0.0/4 IP multicast (former Class D network) RFC 5771
240.0.0.0/4 Reserved (former Class E network) RFC 1700
255.255.255.255 Broadcast RFC 919
Private addressing:
10.0.0.0–10.255.255.255
172.16.0.0–172.31.255.255
192.168.0.0–192.168.255.255
IPv6¶
Addressing¶
Aggregatable Global Unicast 2000::/3
Link-Local Unicast FE80::/10
Unique Local Unicast FC00::/8 AND FD00::/8
Multicast FF00::/8
Global routing prefix: Network ID/prefix used for routing.
Link local address: Packets sent to this, never leave the local link. Assigned to every Ipv6 interface. RTR will not forward.
128 bit long addresses
Uses CIDR principles: prefix/prefix length
x:x:x:x:x:x:x:x:8, where x is a 16-bit hex field
The last 64 bits are used for the interface ID
Address:
Global routing prefix: 2001:1111:2222 (48 bits)
Subnet ID: 16 bit value right after GRP
Interface ID: 64 bit value that ends the address
Routing needs to be enabled twice. Once globally, once interface level.
Global= R1(config)#ipv6 unicast-routing
Solicited-node multicast address: Starts with FE02::1:FF then the last 6 HEX Char.
Example address: 2001:DB8:1001:F:2C0:10FF:FE18:FC0F = FF02::1:FF18:FC0F
2001:0DB8:C003:0001:0000:0000:0000:F00D = 2001:DB8:C003:1::F00D
-Unicast: one to one (global, link local, unique local, compatible)
-Multicast: one to many (also replaces broadcast addresses)
Local link unicast: FE80::/10
Unique local unicast: FC00::/8 and FC00::/8
Multicast: FC00::/8
Every IPv6 enabled interface must contain at least one loopback and one link local address.
Optionally, every interface can have multiple unique local and global addresses.
When IPv6 is used over Ethernet networks, the Ethernet mac address can be used to generate the 64 bit interface id for the host. this is called the EUI64 address. Since mac addresses use 48 bits, additional bits must be inserted to the fill the 64 bits required.