IP is not ICMP pingable: laptop behind mobile tethering

[frgomes]

Hello,

I'm trying to configure my laptop to publish its IPv6 address to dyn.dns.he.net.

When I'm at home it simply works because my router has a IPv6 tunnel already configured and ddclient simply publishes the IPv6 address.
When I'm in Brazil it works because I connect via mobile tethering and the mobile network operator in Brazil supports IPv6.
However, the vast majority of mobile network operators in the UK do not support IPv6 as yet :-( and, in this case, I suppose I should establish a tunnel for my laptop via mobile tethering.

A bit off topic, but I suppose I should have an exclusive IPv4 endpoint allocated to me by the mobile network operator.
More info here: http://www.proroute.co.uk/support/apn-settings/
Quote: "If you are going to use DYNDNS then by using the following APN setting Three mobile should allocate you with a Public IP Address."

Well, supposing that the mobile network operator allocated a public IPv4 endpoint for me, I've headed to tunnelbroker.net and tried to create a new tunnel.
Then I've got the message: "IP is not ICMP pingable. Please make sure ICMP is not blocked. If you are blocking ICMP, please allow 66.220.2.74 through your firewall."

Any idea if and how this difficulty could be circumvented?

Note: I'm not really sure if the mobile network operator really allocated an IPv4 to me.
I've tried http://checkip.dyndns.org/ many times after rebooting the phone many times but I don't have any evidence that IPv4 endpoint(s) I get were allocated exclusively to me.

Thanks a lot,

[cholzhauer]

The tunnel wasn't created because HE was unable to ping your IPv4 address.  Can you confirm that the 66.x address was actually assigned to you and not to a large CGN?

[frgomes]

Hello cholzhauer,

When I've tried to create the tunnel, I've informed the IP address obtained via http://checkip.dyndns.org. In this case, the IP address was 188.28.150.82.
A far as I understand 66.220.2.74 (which belongs to HE) is trying to ping 188.28.150.82 (which belongs to the mobile network operator), without success.

I've configured the APN settings in my mobile phone so that it theoretically requests a public (and exclusive) IPv4 address.
Even supposing that the mobile network operator really allocated a public and exclusive IPv4 for me, I do not have any control of such process and I cannot guarantee that the IP address responds to ICMP.

Thanks

[broquea]

The ICMP check is baked into the broker code and cannot be bypassed, even manually on our side.

[evantkh]

Some ISPs block inbound ICMP echo requests.