Technical problems about the tunnels

[evantkh]

Firstly, why ICMP echo reply is necessary for creating tunnels?

Secondly, it is possible to have a tunnel with multiple endpoints?
Using the same PTP /64 but different routed subnet. For example, the router IP ended with ::2, ::3, ::4 or even other endpoint IPs with their own routed prefix, or clients in public network can join the PTP /64 network directly.

[broquea]

The test verifies that the remote IPv4 endpoint is reachable through the network.

The tunnel is point to point, not point to multipoint. You can create multiple tunnels for your different locations, or allocate a /48 to one, and create your own tunnels to your other locations, and do as you wish.

[evantkh]

The test verifies that the remote IPv4 endpoint is reachable through the network.

The tunnel is point to point, not point to multipoint. You can create multiple tunnels for your different locations, or allocate a /48 to one, and create your own tunnels to your other locations, and do as you wish.

However, some ISPs block ping request.

[broquea]

Maybe there are other tunnel providers that don't check this. No one is forcing anyone to use this service :)

[evantkh]

Maybe there are other tunnel providers that don't check this. No one is forcing anyone to use this service :)

It works on my fixed line but does not work on my mobile device.

[kcochran]

Does your mobile IP address have its own, dedicated, public IPv4 address and isn't behind a NAT of some sort?

Does your mobile service provider pass along other 'unusual' traffic, such as IP protocol 41 marked packets?

[evantkh]

Does your mobile IP address have its own, dedicated, public IPv4 address and isn't behind a NAT of some sort?

Does your mobile service provider pass along other 'unusual' traffic, such as IP protocol 41 marked packets?

The mobile phone has a public IP but filtering incoming ping requests. 6to4 works before but not tested now.

[evantkh]

Does your mobile IP address have its own, dedicated, public IPv4 address and isn't behind a NAT of some sort?

Does your mobile service provider pass along other 'unusual' traffic, such as IP protocol 41 marked packets?

The mobile phone has a public IP but filtering incoming ping requests. 6to4 works before but not tested now.

ping is filtered by the ISP.The phone can be pinged within the network of the same ISP.

[evantkh]

Maybe I can make my own tunnel server and connect my phone to it.

[evantkh]

Tested and it works well with my home-made tunnel.

[evantkh]

In fact, protocol 41 does not depend on ping. Why he is not providing multiple/alternate methods for testing the endpoint IPs. For example, listening to specific port or host a web page on a specific port.