Greetings to the esteemed community here,
I am having very strange problems with implementing dual-stack topology in my Packet Tracer excercise which I have attached here.
The first problem consists of unstable routing using OSPF on IPV6, which manifests in randomly missing routes across every node in my topology. I have already spent a great deal of time trying to unsuccessfully troubleshoot this strange occurence. Nothing appears out of the ordinary to me: all neighbor states are FULL, there are consistent timers everywhere, every device has unique router-id etc. In the end I had to install appropriate floating routes everywhere as a workaround.
The second problem is non-functional IPV6 HSRP on my SVI interfaces configured on D1 and D2 switches. For some reason active and standby group cannot see each other, which is the most likely why I cannot get successful pings between admin and user PC.
Everything described here only happens on IPV6. There is almost the same configuration on IPV4 and I didn't encounter any of these issues. It would be greatly appreciated if someone more experienced could take a look at this and help me track down possible configuration errors.
Thanks in advance!
EDIT: Apparently the .pkt file extension cannot be uploaded here, so here's the download link:
https://tinyurl.com/2p8pjan8
