@castrojuanj
Hello Juan,
I hope you are doing well,
I have labed your question and took a packet capture to see if I can help you understand NDP better.
First off a link-local address is configured in two ways.
- The administrator specifies the link-local address to be used
- The local router uses eui-64 to generate the proper IP address for link-local use
Now if you have a unique local and global unicast IP address assigned to the same interface and it receives an RS, it will the respond with an address for both unique local and global unicast addresses. So no the router only needs to go through the RS/RA process once to get IP addresses, and the auto config command only needs to run on the remote router once.
Also I have included a pcap file that will let you see what I did in wireshark.
NDP example.pcapng (5.2 KB)
I hope this helps!
Scott