Published by Keyboard Banger on

– Remember to activate IPv6 routing and IPv6 CEF

show ipv6 interface brief … prefix

first ping in IPv6:

Link local, link global:

debug ipv6 packet:
show ipv6 route
Connected subnets are displayed as “Connected”. In our case, 2026::1/122 and 2026::34/122. The ip addresses of R3 interfaces are displayed as Local routes.

Problem pinging from R4 to R3: debug ipv6 icmp and debug ipv6 packet
after checking IPv6 unicast routing and IPv6 CEF, R4 still can not ping R3. “Debug ipv6 packet” and “debug ipv6 icmp” give something interesting:

The ping between R2 and R3 did not show any problems, although there’s frame relay between them. There’s frame relay between R4 and R3 too, but it showed a problem. Maybe it’s due to the face that, between R2 and R3 there are point-to-point subinterfaces, whereas R4 connects with its physical serial interface to a subinterface of R3.
To solve the problem, I did the following:

I was having trouble to ping between R1 and R2.

It happened to be a frame-relay mapping issue too:

At this point, all ipv6 subnets are configured. Each router can ping his directly connected neighbor. But there’s no routing. We’ll configure OSPFv3 later.

Let’s configure IPv6 on switch interfaces.
An interesting note to mention with GNS3 is that it does not handle link local addresses and EUI-64 well. Here’s the proof:
– configure ipv6 on DSW1

– configure ipv6 on DSW2

We have a duplicate address message. Checked link local addresses on both switches and found why:
Forget about EUI-64 in GNS3.
We can configure many IPv6 addresses under one interface. So remember to delete any previous address.

Keyboard Banger

Keyboard Banger is a network engineer from Africa. He has been working in network support and administration since 2008. He started writing study notes about certification exams and technology topics a couple of years ago. When he's not writing articles, he can be found wandering on technical forums.


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