Hi there, I am having issues in seeing any hosts which are connected to a IPv6 native link in Slovakia from any of my tunnels connected to this gblon02 pop. I can see the the Slovakian network from another native IPv6 host in Germany and from most if not all trace route checkers that I have tested dotted around the world, so I don't believe its there network which is at fault. The below trace is from one of the SIXXS tunnels connected to gblon02 pop to the Slovakian network. traceroute to 2a00:10d8:10:1:5cf0:f8c0:0:1 (2a00:10d8:10:1:5cf0:f8c0:0:1), 30 hops max, 80 byte packets 1 gw-1083.lon-02.gb.sixxs.net (2a01:348:6:43a::1) 1.416 ms 1.354 ms 41.003 ms 2 gblon02.sixxs.net (2a01:348:0:4:0:3:1:1) 40.944 ms 40.864 ms 40.785 ms 3 ge-0-0-5-20.cs0.thw.uk.goscomb.net (2a01:348:0:4:0:3:0:1) 40.724 ms 40.647 ms 40.586 ms 4 xe-0-1-1.cs0.the.uk.goscomb.net (2a01:348::36:1:1) 40.417 ms 40.375 ms 40.316 ms 5 xe-0-1-0.cs0.gs2.uk.goscomb.net (2a01:348::24:1:1) 40.255 ms 40.178 ms 40.084 ms 6 xe-0-1-0-0.cs1.gs2.uk.goscomb.net (2a01:348::40:1:1) 39.966 ms 33.141 ms 33.130 ms 7 xe-0-1-0.cs0.sov.uk.goscomb.net (2a01:348::41:1:1) 3.201 ms 3.342 ms 3.335 ms 8 ge-1-1-5.rt0.sov.uk.goscomb.net (2a01:348::17:0:1) 2.220 ms 2.219 ms 2.211 ms 9 ge-1-1.r01.londen05.uk.bb.gin.ntt.net (2001:728:0:5000::c1) 18.822 ms 18.820 ms 18.816 ms 10 xe-0-3-0-3.r02.amstnl02.nl.bb.gin.ntt.net (2001:728:0:2000::13a) 19.502 ms 19.506 ms 19.499 ms 11 ae-3.r23.amstnl02.nl.bb.gin.ntt.net (2001:728:0:2000::125) 17.356 ms 17.528 ms 17.287 ms 12 ae-1.r20.frnkge04.de.bb.gin.ntt.net (2001:728:0:2000::6d) 106.138 ms 104.116 ms 104.105 ms 13 ae-2.r21.frnkge03.de.bb.gin.ntt.net (2001:728:0:2000::1) 26.686 ms 26.592 ms 36.184 ms 14 decix.xcr1.fix.cw.net (2001:7f8::4f9:0:1) 30.865 ms 30.941 ms 30.277 ms 15 ae1-xcr1.fri.cw.net (2001:5000:0:bc::1) 90.831 ms 26.214 ms 31.696 ms 16 2001:5001:200:a::2 (2001:5001:200:a::2) 45.398 ms 34.288 ms 33.723 ms 17 2001:af0:c1:2007::2 (2001:af0:c1:2007::2) 40.335 ms 45.975 ms 40.769 ms 18 * * * 19 * * * 20 * * * 21 * * * 22 * * * 23 * * * 24 * * * 25 * * * 26 * * * 27 * * * 28 * *^C And this trace is from native link on another ISP which this ones in Germany (hetzner). traceroute to 2a00:10d8:10:1:5cf0:f8c0:0:1 (2a00:10d8:10:1:5cf0:f8c0:0:1), 30 hops max, 80 byte packets 1 * * * 2 2a01:4f8:100:6060::1 (2a01:4f8:100:6060::1) 4.897 ms 4.944 ms 4.996 ms 3 hos-tr1.juniper1.rz10.hetzner.de (2a01:4f8:0:10:1:0:10:1) 4.453 ms 2a01:4f8:0:10:4:0:10:2 (2a01:4f8:0:10:4:0:10:2) 4.429 ms hos-tr2.juniper1.rz10.hetzner.de (2a01:4f8:0:10:2:0:10:1) 4.436 ms 4 2a01:4f8:0:2::1:4 (2a01:4f8:0:2::1:4) 6.381 ms 6.367 ms 6.346 ms 5 fra-decix1.gtsce.net (2001:7f8::15d4:0:1) 6.853 ms 6.856 ms 6.843 ms 6 2001:af0:c1:2007::2 (2001:af0:c1:2007::2) 18.931 ms 19.072 ms 19.024 ms 7 2a00:1298:5588:11::2 (2a00:1298:5588:11::2) 19.415 ms 19.056 ms 18.981 ms 8 2a00:10d8:10:1:5cf0:f8c0:0:1 (2a00:10d8:10:1:5cf0:f8c0:0:1) 18.959 ms 19.093 ms 18.601 ms As you can see the last one is successful going to the Slovakian network if done native to native links (diff isps). I also can see the native networks from all checkers ive tested with however not all will work checking against the sixxs tunnel so I expect the issue is something to do with sixxs ranges and some ISP's. The problem seems to be this router: 2001:af0:c1:2007::2 it seems that it drops all packets coming from the sixxs network. I am not sure if you can do anything about this but I can't seem to track down the offending ISP to see if they can fix this, so I was hopping you maybe able to advise or manage to fix it yourself's as this I expect is stopping a fair bit of potential locations which you can reach on your awesome tunnel service. Kind Regards, Simon