3 ms·

Here's the other side of the story: Not a sysadmin, but I'm an independent programmer with an online app. I've set up a Debian vps at OVH with IPv6 and it was u

by tajen 11y ago

Here's the other side of the story: Not a sysadmin, but I'm an independent programmer with an online app. I've set up a Debian vps at OVH with IPv6 and it was unbearably slow. I used to believe it was OVH, but the reason seems to be that most things e.g. package managers wait for the request in IPv6 (or the one to the DNS) timeout before trying IPv4. An apt-get upgrade takes hours. I guess there's some kind of configuration to improve that, but when step 0 of setting up IPv6 starts with problems, I just stick to stacks that I can manage.

the_mitsuhiko 11y ago
The problem there is probably the DNS resolution. I like the way apple does it: they resolve AAAA and A in parallel. Whatever comes back first is being used for the connection attempt. Much better than waiting for a ~5 second timeout on AAAA before calling back to A.
- scurvy 11y ago
  This is no longer the case. Their implementation of Happy Eyeballs now prefers IPv6 over IPv4. This is as of iOS 9 and El Capitan.
  - the_mitsuhiko 11y ago
    > This is no longer the case. Their implementation of Happy Eyeballs now prefers IPv6 over IPv4. This is as of iOS 9 and El Capitan. It prefers, but only if it gets a response within 25milliseconds. It still queries AAAA and A in parallel.
    - scurvy 11y ago
      > It prefers, but only if it gets a response within 25milliseconds. It still queries AAAA and A in parallel Correct. The large technology companies that shape the world are indicating their preference and shift towards an IPv6 world, yet you still claim that you see no benefit? You don't want to be on board with them?
      - the_mitsuhiko 11y ago
        > yet you still claim that you see no benefit? Did you reply to the wrong thread? I did not indicate my preference here, I replied to OPs question about why his server might be slow and what other systems are doing.
voltagex_ 11y ago
I've also noticed this. My home ISP (Internode, RIP) provides an IPv6 range. I dutifully set up AAAA records for a couple of my servers and then ended up disabling them either on the client or server side as things as simple as SSH were timing out. I don't think it was DNS, I'm fairly sure there was an MTU issue but I didn't dig into it that much.

by tajen 11y ago

the_mitsuhiko 11y ago

The problem there is probably the DNS resolution. I like the way apple does it: they resolve AAAA and A in parallel. Whatever comes back first is being used for the connection attempt. Much better than waiting for a ~5 second timeout on AAAA before calling back to A.

scurvy 11y ago
This is no longer the case. Their implementation of Happy Eyeballs now prefers IPv6 over IPv4. This is as of iOS 9 and El Capitan.
- the_mitsuhiko 11y ago
  > This is no longer the case. Their implementation of Happy Eyeballs now prefers IPv6 over IPv4. This is as of iOS 9 and El Capitan. It prefers, but only if it gets a response within 25milliseconds. It still queries AAAA and A in parallel.
  - scurvy 11y ago
    > It prefers, but only if it gets a response within 25milliseconds. It still queries AAAA and A in parallel Correct. The large technology companies that shape the world are indicating their preference and shift towards an IPv6 world, yet you still claim that you see no benefit? You don't want to be on board with them?
    - the_mitsuhiko 11y ago
      > yet you still claim that you see no benefit? Did you reply to the wrong thread? I did not indicate my preference here, I replied to OPs question about why his server might be slow and what other systems are doing.

voltagex_ 11y ago

I've also noticed this. My home ISP (Internode, RIP) provides an IPv6 range. I dutifully set up AAAA records for a couple of my servers and then ended up disabling them either on the client or server side as things as simple as SSH were timing out. I don't think it was DNS, I'm fairly sure there was an MTU issue but I didn't dig into it that much.