ISP's Blocking SIT Encapsulation?

[sysgeek]

Is anybody aware of any ISP's blocking sit encapsulation? I have AT&T DSL at my house and I can't get a sit encapsulated tunnel to come up from my house to Tunnel Broker. However, I can connect to Tunnel Broker via pptp and then create the sit encapsulated tunnel that way, which will then pass the IPv6 traffic. For some reason, it appears as if AT&T is blocking the protocol.

[doneill]

plenty do really, telus mobility blocks GRE tunnels in a way, they work for a few minutes before spontaneously stopping passing packets.

according to customer service one must purchase a VPN Package for $5/mo to have this "feature".

considering crippled connectivity wasn't specified in the SLA, it really is a crock for them to charge extra for basic connectivity like that, but they do.  they offered to give me the feature for free, not understanding my explanation that they can't legally do that afaik.