IPv6 address not pinging from (Router) to Multi switch interface

[sincerefrank366]

Compliments,

I built a network with both IPv4/IPv6 the Multi switch is configured as the layer 3 router and the (Router) is the external network site. All pings are working except the Router to Multi switch IPv6 ping the two interfaces have the same link-local address but the IPv4 can ping the same interface, please advice. Many thanks.

Note: the Router in bracket is the external Router.

[Harold Ritter · Accepted solution]

Hi @sincerefrank366 ,

> the two interfaces have the same link-local address

What two interfaces are you referring to?

Is this a Cisco Packet Tracer simulation? If so, could you please zip the .pkt file and upload it so we can look at it.

Regards,

[sincerefrank366]

I have sent it now. Thanks.

[sincerefrank366]

password cisco

[Harold Ritter · Accepted solution]

Hi @sincerefrank366 ,

I can see a couple of things.

1. You should not configure the same link local address (LLA) for two routers on the same subnet. In your case, the router and the L3 switch are both configured with FE80::5. The LLA should be unique on the subnet. This will definitely prevent the ospfv3 session to come up.

2. The fact that you can't ping between the router and the L3 switch seems to be related to an issue with Cisco Packet Tracer (CPT) on the L3 switch. On the L3 switch, CPT tries to resolve the IPv6 address of the router (2001:db8:db8:1::1) on VLAN 1, even though this prefix is configured on gi1/0/6. A quick fix for this issue is to shutdown VLAN 1.

Regards,

[sincerefrank366 · Accepted solution]

Many thanks Harold I really appreciate your solution and concern.

[Harold Ritter]

You are very welcome @sincerefrank366 and thanks for the feedback

[sincerefrank366]

I did as you said and it is working perfectly. Thanks once again Harold.

[Harold Ritter]

You are very welcome and thanks for the feedback @sincerefrank366 

[sincerefrank366 · Accepted solution]

I tried uploading the file but Packet tracer file not supported massage pops up.

The issue is for Multi switch ping to Router or Router to Multi switch via IPv6 but IPv4 is pinging.