I ran into a weird problem the other day where my IPv6 OSPF adjacency kept flapping every 40 sec(dead timer) and then reestablishing.
Before you go crazy trying to troubleshoot this problem, check this:
1. Check to see if there is a switch in between your IPv6 routers, make sure this switch supports IPv6! if there is [...]

Configuring Access lists in IPv6 in very much the same as in IPv4. You create the ACL and apply it to the interface in the proper direction. Here is an example of how to apply an access list that prevents all traffic from a specific network.
We will use Network: FEC0:AB11:1:33::/64. We are going to prevent [...]