Somes sites are only work with ipv6

I'm currently on 18.06.02 on an o2 Box 6431 have an interesting problem. My ISP (Deutsche Telekom) provides v4 and v6 addresses, and so far everything is fine and dandy. But I realized the other day that some sites only work in ipv6 mode.

One of them is netflix here is the output for v4:

user@OpenWrt:~# ping -c 3 netflix.com
PING netflix.com (52.19.56.133): 56 data bytes

--- netflix.com ping statistics ---
3 packets transmitted, 0 packets received, 100% packet loss

And v6:

user@OpenWrt:~# ping6 -c 3 netflix.com
PING netflix.com (2a01:578:3::3411:e3ae): 56 data bytes
64 bytes from 2a01:578:3::3411:e3ae: seq=0 ttl=47 time=32.333 ms
64 bytes from 2a01:578:3::3411:e3ae: seq=1 ttl=47 time=32.254 ms
64 bytes from 2a01:578:3::3411:e3ae: seq=2 ttl=47 time=32.411 ms

--- netflix.com ping statistics ---
3 packets transmitted, 3 packets received, 0% packet loss
round-trip min/avg/max = 32.254/32.332/32.411 ms

I tried different v4 DNS servers like: 1.1.1.1, 1.0.0.1, 8.8.8.8, 9.9.9.9 etc.

But regardless of the DNS-server I used v4 does not work.

The iCloud imap servers are also affected. They only have a v4 address and I cannot reach them.

user@OpenWrt:~# ping p40-imap.mail.me.com
PING p40-imap.mail.me.com (17.36.205.69): 56 data bytes

--- p40-imap.mail.me.com ping statistics ---
3 packets transmitted, 0 packets received, 100% packet loss

Has anyone experienced such an issue?

Just tried it and I basically get the same result than you do.

ping to netflix.com via IPv6 works, no response via IPv4.

The iCloud IMAP server only resolves to IPv4 but also does not respond to ping.

I'm using 18.06.02 on a R7800 and my ISP is Primacom/Pyur with proper IPv4/IPv6 dual stack (no DSLite).

Since I'm not using iCloud / Netflix I can't tell you if this is normal behavior or not. They might just be configured to not respond to ping requests (or something on that route is dropping the ICMP packets).

The weird thing is. When I disable ipv6 in firefox

network.dns.disableIPv6 = true

I cannot access the page. So I don't think that they disabled the ping response. My mail client also complains that it cannot reach the imap server.

So for some reasons routing to some ip-addresses seems to be broken. As far as I remember, I didn't have these problems when I used the ISPs Router (Speedport W724V).

Then it might either be a local problem (since both our ISPs are from Germany) or it is actually a problem in OpenWRT.

I remember a case with my ISP that some routes to Akamai were broken a couple of years ago, and sites like samsung.com or the Steam store wouldn't work.

It could be something like this again (certain routes to a CDN being borked) but this time not restricted to just a single ISP.

But so far I haven't noticed any site / service not working on my end (besides the ping tests right now).

I can confirm your results from a german o2/telefonica link, interestingly:

                                                       My traceroute  [v0.92]
computer.lan (192.168.1.222)                                                                            2019-03-31T20:47:10+0200
Keys:  Help   Display mode   Restart statistics   Order of fields   quit
                                                                                           Packets               Pings
 Host                                                                                    Loss%   Snt   Last   Avg  Best  Wrst StDev
 1. router.lan                                                                            0.0%    14    1.2   1.4   1.2   1.9   0.2
 2. loopback1.93.brun.0035-04.fra.de.net.telefonica.de                                    0.0%    14   22.8  23.8  22.8  26.3   1.2
 3. bundle-ether31.0001.dbrx.02.fra.de.net.telefonica.de                                  0.0%    14   23.2  23.1  22.7  23.4   0.2
 4. bundle-ether1.0005.prrx.02.fra.de.net.telefonica.de                                   0.0%    14   23.1  23.2  22.9  23.5   0.2
 5. decix2.amazon.com                                                                     0.0%    14   23.2  24.8  23.0  41.5   4.9
 6. 54.239.106.228                                                                        0.0%    14   23.9  24.1  23.8  24.6   0.2
 7. 54.239.106.155                                                                        0.0%    14   23.5  24.7  23.0  38.5   4.0
 8. 205.251.232.102                                                                       0.0%    14   44.6  45.4  44.5  49.1   1.3
 9. 54.239.44.146                                                                         0.0%    14   44.6  45.1  44.2  49.1   1.2
10. ???
11. 52.93.6.132                                                                           0.0%    14   87.9  66.3  47.8  88.0  13.9
12. 52.93.101.23                                                                          0.0%    13   43.9  44.9  43.9  52.1   2.2
13. 52.93.101.30                                                                          0.0%    13   47.6  60.6  45.6  87.4  16.9
14. 52.93.7.103                                                                           0.0%    13   44.8  45.2  44.6  46.0   0.4
15. ???

According to whois 52.93.7.103 belongs to amazon and Netflix runs on AWS, so I believe your ISP might be innocent here...

                                                       My traceroute  [v0.92]
computer.lan (192.168.1.222)                                                                            2019-03-31T20:49:12+0200
Keys:  Help   Display mode   Restart statistics   Order of fields   quit
                                                                                           Packets               Pings
 Host                                                                                    Loss%   Snt   Last   Avg  Best  Wrst StDev
 1. router.lan                                                                            0.0%    13    1.4   1.3   1.2   1.4   0.1
 2. loopback1.93.brun.0035-04.fra.de.net.telefonica.de                                    0.0%    13   23.0  25.0  22.8  34.9   4.1
 3. bundle-ether31.0002.dbrx.02.fra.de.net.telefonica.de                                  0.0%    13   23.1  23.2  22.7  23.8   0.3
 4. bundle-ether2.0005.prrx.02.fra.de.net.telefonica.de                                   0.0%    13   22.9  23.2  22.8  23.6   0.3
 5. apple-defra1-isp-gw1-decix1.apple.com                                                 0.0%    13   23.6  25.9  23.2  43.6   5.6
 6. 17.1.3.1                                                                              0.0%    13  158.1 160.1 158.1 163.2   1.8
 7. 17.0.8.142                                                                            0.0%    13  159.3 159.7 158.6 161.4   1.0
 8. 17.1.0.19                                                                             0.0%    13  205.1 162.2 158.2 205.1  12.9
 9. 17.1.0.119                                                                            0.0%    13  158.7 158.7 158.2 159.1   0.2
10. 17.0.8.55                                                                             0.0%    13  158.6 159.0 158.2 161.7   1.0
11. ???
12. 17.1.1.41                                                                             0.0%    13  157.9 159.7 157.9 169.0   3.1
13. ???

And whois claims 17.1.1.41 is operated by apple. Again my ISP seems to be doing what I pay them for...

Yeah same for me. Transit looks fine.

But then it fails on hops close to the end of the route with the IPs belonging to AWS and Apple.

Not an OpenWrt problem it seems. I connected my computer via a mobile hotspot with my phone (o2 Telefonica in Germany) and still the same problems.

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