SSH in Packet Tracer - IPv4 works but not IPv6

[KennyRoberts]

Hi.

I have encountered a problem with SSH on Packet Tracer.

The topology is one PC connected to a router.

I have configured the router with both IPv4 and IPv6 addresses on the G0/0 interface, and have also configured SSH version 2 on the router. 

PC ---------- Router

Router G0/0 interface = 192.168.1.1/24 and 2001:DB8:ACAD:1::1/64

PC = 192.168.1.10/24 and 2001:DB8:ACAD:1::10/64

The problem is as follows (this is done in a step by step manner):

1- PC is able to ping the router on both IPv4 and IPv6

2- PC ssh to router on IPv4 = successful

3- PC ssh to router on IPv6 = unsuccessful

4- Reload router

5- PC is able to ping the router on both IPv4 and IPv6

6- PC ssh to router on IPv6 = successful

7- PC ssh to router on IPv4 = unsuccessful

I have tried with the 4331, 2901, 2911 routers, and the problem exists in all three routers.

I have attached the Packet Tracer file that I am working with.

Is this a problem with Packet Tracer, or am I missing something with my router configurations?

Thanks!

[Georg Pauwen]

Hello,

the actual addressing seems to be the problem, not really sure why that is...

If you use the address format below:

Router

interface GigabitEthernet0/0/0
ip address 192.168.1.1 255.255.255.0
duplex auto
speed auto
ipv6 address 2000::1/64

PC

2000::2/64

the IPv6 SSH works.

[KennyRoberts]

Thanks for your reply.

The issue is if we perform the SSH over IPv4 first (which succeeds), and then perform SSH over IPv6 after that, the second SSH attempt will fail.

Conversely, if we perform the SSH over IPv6 first (which succeeds), and then perform SSH over IPv4 after that, the second SSH attempt will fail.

I tried changing the router's IPv6 address to 2000::1/64 and the PC's IPv6 address to 2000::2/64 as per your suggestion, but the issue still remains.

[Georg Pauwen]

Hello,

sorry for that, I misread your question (although I cannot get ssh working with the 'long' version of the IPv6 at all).

Either way, what if you shut/no shut the router interface, or reload the router after the first IPv4 ssh ? Definitely looks like a (one of the many) bug(s) in PT...