IPv6 BGP session stuck in open sent. Anyone here using tunnelbroker.ch?

Is anyone using tunnelbroker.ch here? I literally try for three days to get a working IPv4 BGP session. With IPv6 everything works but for IPv4, no matter which options I use I receive an immediate TCP FIN,ACK after the OPEN message from the endpoint.

I have tried any conceivable option and setting (my endpoint is Mikrotik if that matters).

I have even intercepted and decoded the OPEN message and it is exactly correct:

• Marker=16x FF
• Length=45
• Type=1(OPEN)
• Version=4
• MyAS=AS_TRANS
• HoldTime=180
• BGP Identifier=MyIP
• OptParamsLen=16
• Optional Parameter: 2(Capability); Length=14
  • Route Refresh Capability
  • Support for 4-octet ASN Capability
    • my 32 bit ASN
  • Multi Protocol extensions capability
    • AFI: (1) IPv4
    • SAFI: (1)Unicast

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My only explanation is that tunnelbroker.ch is broken. And only the IPv4 BGP part.

Hence my hope that someone here is using this and can confirm/disconfirm.

Or give me any advice what else I could try.

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