Enabling Ping / Echo requests on IPv6 - which protocol and ports?

[#1]

My router will not respond to IPv6 echo requests and I wish to run a Thinkbroadband.com Broadband Quality Monitor (BQM).

So the plan is to let the ping request through the firewall and direct it towards a Windows 11 machine that has had its firewall adjusted to respond to the IPv6 ping / echo request from Thinkbroadband.

So far, I've succeeded in allowing the thinkbroadband request from a single IPv6 IP address through the router firewall and directing it to a single IPv6 address on the Win 11 machine. The BQM now works - so success!

However to achieve this I've had to allow what my TP-Link ER605 calls "Service Type" ALL.

I believe that I can define new "service types" and wish to do so to limit the type of traffic that passes through the firewall to my Win 11 machine. Here is a screen shot of the page for adding a new service type:

Am I correct in thinking that the protocol should be ICMP?

What Source Port Range and Destination Port Range do I need?

[#2]

Ok, Sorry to be the first back here. I've just realised that I may have asked about the wrong options - If it is ICMP that I need then the questions should have been

What Type?  

What Code?

Thanks

Ian

[#3]

If it helps, what I did on my Openwrt system

Create an IP group containing the Think broadband IPs

Allow ICMP  through the firewall where the source IP is the above group

How/if you can do that with the native firmware I'm not sure

[#4]

The native firmware allows the creation of an IPv6 group - which I've done.

It also allows adding an access control rule - which I've done.

However I wanted to restrict the rule to only allow echo requests which, as standard it would not let me, the only option that would work was "service type" ALL.

I've now managed to create a new "Service type" which only only allows the ping requests through (at least I think that's what's happening!)

To answer my own question,

Echo Requests are ICMP , Type 8, Code 0.

Perhaps I should have done the internet search before asking here.