Ping on loopback address doesn't work (Packet Tracer)

[david_st]

Hello,

when I try to ping ::1 (Loopback address) on a router, it just timeouts.

Does someone know why?

Is this a bug in the packet tracer?

PT Ver. 8.1.0

Best wishes

David

[balaji.bandi]

not sure what is the full ipv6 address you trying : check below article helps

https://docs.microsoft.com/en-us/windows/win32/winsock/configuration-1-single-subnet-with-link-local-addresses-2

[david_st]

But 127.0.0.1 also doesn't work on the router. On the client both work

[balaji.bandi]

But 127.0.0.1 also doesn't work on the router

explain more and show us the configuration to understand better ?

[david_st]

---

@balaji.bandi wrote:

But 127.0.0.1 also doesn't work on the router

explain more and show us the configuration to understand better ?

---

I haven't configured anything, I only created a new PT file and created an PT-Router. Then I went to the CLI and typed in

enable

and

ping 127.0.0.1

or

ping ::1

That's it! Timeout.

On the client, it works perfectly fine.

You can try it out yourself.

[balaji.bandi]

by default any csico device do not have any IP address or Loopback configured, unlike PC.

show run or show ip interface give you information, what is configured on Router or Switch.

Note : Do not compare PC vs cisco Devices.

You can try it out yourself.

This not going to work, as basic theory since any router and switch not come with preloaded config - i am not a PT great user.

Suggestion here is, if you taking any training with instructor in the training, i would advise to ask question to get clarity.

[david_st]

Do you know, how I configure the loopback address?

[balaji.bandi]

https://bfy.tw/SMGN

[david_st]

Not very helpful.

I've been searching for this for very long, but I can't find a solution.

I only find how to configure a loopback interface, but this has nothing to do with loopback address configuration.

[Martin L · Accepted solution]

Yes, I think it is a bug or more precisely missing functionality in PT as PT is only a simulator that should behave like IOS but it is not real IOS. 

On real routerping ::1 asking for outgoing interface with error : % No valid source address for destination`

Ping ipv6 loopback is to test the internal IPv6 stack to ensure its configuration and functionality.  It does not test reachability to any external device, nor does it confirm that IPv6 addresses are properly configured on the host.

Regards, ML
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[david_st]

Thank you!