• Welcome to Hurricane Electric's IPv6 Tunnel Broker Forums.

News:

Welcome to Hurricane Electric's Tunnelbroker.net forums!

Main Menu

Recent posts

#1
Questions & Answers / Re: Strange TCP behavior from ...
Last post by Kyle Butt - June 09, 2023, 10:48:18 AM
I was able to fix it with a tweak to the MTU of the tunnel.

I set the tunnel to 1480, but more importantly, I set the ipv6 router advertisements to include the MTU. I suspect that the initial mss was derived from the MTU of my local link, and was causing problems with fastly. With the fastly routes having a smaller MTU, things go smoothly again.
#2
Questions & Answers / Re: Google forcing ReCAPTCHA o...
Last post by cshilton - June 09, 2023, 07:46:15 AM
I had to avoid searching google over IPv6 for about a week but now things seem to be working. Are other people seeing this too or have I misdiagnosed things?


- Chris
#3
Questions & Answers / Re: MTU? Problem with various ...
Last post by bmhughes - June 08, 2023, 02:41:43 AM
Fully agree with the above, just trying to get it solved. I'm not pointing any fingers, my tunnel has worked perfectly for many years and I'm grateful to HE for providing it.

#4
Questions & Answers / Re: MTU? Problem with various ...
Last post by bbigg - June 07, 2023, 05:47:04 AM
Hi,

I do get what you're saying - I think the problem - based on what I've seen - is upstream with the CDNs.

My hope/ expectation was that you might have a little bit more weight than me as an individual in raising this as an issue to be addressed. From what I've read it looks like it's pretty intractable and tunnels/ mismatched MTUs are going to be even more of a pain in IPv6 than v4.

Of course, if someone has some magic sauce/ workaround to prove me wrong I'm most definitely not proud - I just want to solve the problem..
#5
Understood, then why the UI offers enabling DDNS on the AFSDB records?

Is it a bug?

#6
Questions & Answers / Re: MTU? Problem with various ...
Last post by kcochran - June 03, 2023, 09:40:14 AM
We don't drop PTBs or anything on the tunnels.

The tunnel servers are 1500 to their upstream device, and our backbone is 9000 across the board, going down to 1500 at most borders, since jumbo frames rarely exist on IXPs, and many peers choose to stay at 1500.
#7
General Questions & Suggestions / Re: DDNS AFSDB update request...
Last post by kcochran - June 03, 2023, 09:37:56 AM
A, AAAA, and TXT are the only records supported.

As an AFSDB record points to a hostname, couldn't you just update the A record associated to the hostname?
#8
Questions & Answers / Re: Issues with tserv1.lon2
Last post by bmhughes - June 03, 2023, 09:13:09 AM
Same issue in the UK, looks like an MTU issue somewhere on HE's side. I've enabled TCP-MSS clamping down to 1370 and that is working around it for the time being, can't seem to go much higher than that.
#9
Questions & Answers / Re: MTU? Problem with various ...
Last post by bmhughes - June 03, 2023, 09:13:02 AM
Same issue in the UK, looks like an MTU issue somewhere on HE's side. I've enabled TCP-MSS clamping down to 1370 and that is working around it for the time being, can't seem to go much higher than that.
#10
Questions & Answers / Re: Strange TCP behavior from ...
Last post by bmhughes - June 03, 2023, 09:11:53 AM
Circa 1370 bytes is about as high as I can get reliably.