My (final) ipvsEx questions!

altdrugz

Hello, I ve been studying and watching videos the last 2 weeks in order to understand this ipv6 thing and still im confused. My resources are Odom's and Lammle's book INE and CBT vids.

First I will start with what I already know:

FE80::/10 Link Local addresses: I ve test them out, and in my lab I was able to test that my linux pc was having an FE80 address when it booted. I also saw that when I do ipv6 enable in a routers interface it assigns one FE80 address as well.
Characteristics:
-> In RS messages from the host in order to figure out the DHCP.
-> Arent routable, although routers advertise their next-hop Link Local address for a destination route(?).
-> Purpose: packets sent in the local subnet.

I wont spam you with the multicast addresses and the global unicast addresses because I think that I have already understood their meanings.

BUT... I cannot understand the meaning of the "Unique Local" addresses (start with FD00::/. In Odom's book says that these addresses are like ipv4 private ones but if its so, whats the meaning of the Link Local addresses??? So my question in summary:
Whats the difference between link local and unique local addresses and whats their purposes?
and since routers advertise their link local addresses how they are able to know the destination Global (public) addresses? Surely it is missing a vital point of information in both books...

ps: Im about to take the exam, and its amazing how many time im wasting trying to understand this ipvsEx thing. I made a gns3 lab in order to understand how everything works and debug it but still im confused... I finished with all the other materials in around 1 month and im for more than 15 days in ipv6...

ps2: They should arrange the FF::S For Sake address in this ipvsEx implementation... **rrrage**

theodoxa

IPv6
IPv4


Automatic IP Addressing
"Link-Local"
"APIPA"



FE80::/10
169.254.0.0/16


Private IP Addressing

"Unique Local"

RFC 1918

FC00::/7

10.0.0.0/8

172.16.0.0/20

192.168.0.0/16

Zartanasaurus

That's a good chart. The FE80 addresses are like the APIPA addresses in the IPv4 world. They exist only on the link can't be routed anywhere.
The private addresses are "private" but they can be routed on a private network.

altdrugz

But I am able to ping the link-local addresses. That means that the only difference between link local and unique local is the fact that unique ones are locally routed between segments?

Zartanasaurus

You can ping link local addresses if you have an interface on that link.