How ping6 works when i ping global-unicast address ?



I would like to ping from host A to host B which are in same link.. I know how the address resolution works when I use link local address. ie; host A derives the solicit node multicast address from the link-local address of host B and sends the Neighbor Solicit message to B, and A gets the B's mac address through NA from host B, finally it builds the pkt and ping host A.

Now my question is how the address resolution will work when i ping global unicast address of host B from host A.

Thanks in advance,



  • Substitute ARP with ND and the rest remains pretty much the same. Below is a nice link if you want more details.

  • The process is very similar to the one for link-local addresses. You could easily observe this for yourself if you set up a simple topology with GNS3. Connect 2 routers over ethernet/serial, boot them, assign IPV6 addrresses, and ping. Before you ping, start the wireshark capture. You will be able to see exactly what goes on in this very same scenario. Its really helpful once you actually look at the exchange of messages and the sequence of events that you are trying to figure out.

    Each IPv6 router will generate a solicited node multicast address for each ipv6 address that it has configured for a given interface, including both link-local and global unicast. 

    Since both routers know how to derive this address based on the full IPV6 address, router A can send a neighbor solicitation msg to router B to the solicited node address that B configured for itself. B will reply with its mac address, then the actual forwarding can take place. Its the same exchange the occurs with the link local address. A sends a NS, B replies with a NA. The solicited node address is derived through the very same method.

    Try it out for yourself, it should not take you more than 5 minutes to set this up. 

  • Thanks a lot HS628 and plucena24, that makes sense..

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