IPv6 Packet Tracer Bug

After about an hour of struggling I finally figured out that Cisco’s Packet Tracer 6.1 has a bug in it in terms of IPv6 routing. When using the

ipv6 route
command, be sure to use an IP address for the destination, not a port address.

I created a simple little setup, based on the hands-on lab 14.2 in Todd Lamme l’s CCNa book. Three routers, one connected to second which was connected to a t hird. RouterA—RouterB—RouterC. Simple. I turned on ipv6 routing, assigned an address, and created IPv6 routes using the outgoing interface. And then no matt er what I tried, I could not ping between the two subnets. I was able to ping to one interface on the middle router, but not to the other interface. I checked f or mistypes, did the same thing for IPv4 and that worked fine. I couldn’t find t he problem at all. So I started to change things, and eventually used the neighboring IP address rather than the interface, and magically things started to work.

So the point is, if you are playing around with IPv6 in Packet Tracer, do this:

ipv6 route 2001:db8:3c4d:1::/64 2001:db8:3c4d:2::1
rather than this:
ipv6 route 2001:db8:3c4d:1::/64 g0/0