Solicited-Node Multicast Address:
ff02::0001:ff + Last 6 hex digits of unicast address
Example:
Unicast address: 2001:0db8:0000:0001:0f2a:4fff:fea3:00b1
-->
ff02::0001:ffa3:00b1
Shortened:
ff02::1:ffa3:b1
Neighbor Discover Protocol (NDP)
Replaces IPv4 ARP
Uses ICMPv6 and solicited-node multicast addresses to learn MAC address of other hosts.
NS = Neighbor Solicitation = ICMPv6 Type 135 = NDP equivalent of ARP Request
NA = Neighbor Advertisement = ICMPv6 Type 136 = NDP equivalent of ARP Reply
R1#show ipv6 neighbor
^ Shows the IPv6 Neighbor Table
This is the equivalent of IPv4 MAC Table
Displays:
IPv6 Address Age Link-Layer Addr State Interface
FE80::C802:9FF:FE7C:8 0 ca02.097c.0008 REACH Gi0/0
2001:DB8::78:9ABC 0 ca02.097c.0008 REACH Gi0/0
NDP also has a process to automatically discover routers on the local network:
RS = Router Solicitation = ICMPv6 Type 133
Asks all routers on local link to identify themselves
Sent when interface connects to network
Sent to multicast address FF02::2 (all routers)
RA = Router Advertisement = ICMPv6 Type 134
Router announces its presence and info about the link
Sent in response to RS messages and periodically resent
Sent to multicast address FF02::1 (all nodes)
Summary:
RS = Type 133 = Sent to FF02::2 (all routers)
RA = Type 134 = Replies to FF02::1 (all nodes)
NS = Type 135 = Sent to solicited-node multicast ff02::0001:ff + Last 6 hex
NA = Type 136 = Reply to NS
SLAAC
Stateless Address Auto-configuration
Automatically configures IPv6 addresses
Host uses RS/RA messages to learn IPv6 prefix of local link and then use EUI-64 to generate IPv6 address
R2(config-if)#ipv6 address prefix/prefix-length eui-64
^ This requires the prefix and prefix-length
vs
R2(config-if)#ipv6 address autoconfig
^ This uses SLAAC. No need to know prefix/length.
Duplicate Address Detection (DAD)
(Asks Dad if I can use this IPv6 address before I start using it.)
Uses NDP to see if anything else is using my configured IP address.
Host sends an NS using its own IP address.
If no reply, device knows the address is OK. (Thanks, Dad.)
If device gets a NA reply, not OK.
IPv6 Static Routing
ipv6 route destination/prefix-length {next-hop | exit-interface [next-hop]} [ad]
Recall "ad" = Administrative Distance
Network route:
R1(config)#ipv6 route 2001:db8:0:3::/64 2001:db8:0:12::2
^ This is also a recursive route because the router will have to look up how to get to 2001:db8:0:12::2
Host route:
R2(config)#ipv6 route 2001:db8:0:1::100/128 2001:db8:0:12::1
R2(config)#ipv6 route 2001:db8:0:3::100/128 2001:db8:0:23::2
^ Notice with these two commands we specified the prefix length of /128.
Each line is defining a very specific route to a specific host.
Default route:
R3(config)#ipv6 route ::/0 2001:db8:0:23::1
^ Like 0.0.0.0/0 in IPv4
[These are my notes from Jeremy's excellent CCNA course which can be viewed here.]
