I am implementing IPv6 in my network and for now I have my own routable IPv6 /48 block, Cisco routers, Cisco switches, OSPF between them and several hosts. Its all working fine, but there is something confusing, like:
Most utilities I can use are showing link-local addresses (LL) and I see no fast way to determine which host own it. For example I want to know what router was chosen by host and I use
netstat -r6and see some LL or two. To understand which host it is I have to login onto any possible router to see what link-level address it own. I see possible options to solve this:
Host can register LL in DNS. However I think its quite improbable because address assigning is usually not a userland function.
There may be a utility which can search through network and say something about LL.
I can assign manual LL address for routers which will be more readable.
I can make routers to do RAs with unique address instead of LL. Some people says its always LL, but I am not sure (details follow).
Its always said that local routes are done with local address, but it seem to be not always true:
switch#show ipv6 route ON2 ::/0 [110/1] via 2001:DB8:FFFF:27::E, Vlan27 ON2 2001:DB8:FFFF:20::/64 [110/20] via FE80::223:5DFF:FE0A:B95B, Vlan27 C 2001:DB8:FFFF:27::/64 [0/0] via Vlan27, directly connected
The one sending default route via OSPF with unique is Cisco ISR G2 router, and the one sending route with LL is Cisco 3750-E switch. The question are:
- is it OK to have route destination as a unique address? I always thought that destination address is always local because it demand zero effort to determine MAC and send packet since every host have neighbor table with LL<->MAC.
- am I missing some configuration which can use unique addresses in RAs and OSPF destination or its just different behavior and does not matter?