Hi, I resolved the same problem 😉 on my systems I run the networkmanager and this works long time - I'm not sure but I think the problem was that systemd gets or starts its own revolver service. After disabling it and deleting the linked resolve.conf the networkmanager creates it after a restart again and it works. Greets, Marcel Am 22.01.2017 17:31 schrieb "Robin via arch-general" < arch-general@archlinux.org>:

Hi,

seems like a ipv6 related problem. Your DNS Lookup is v4, first ping is v6 and second ping is v4 again. Try to ping the ipv4 address of google.com. But im pretty sure this is not arch related.

Maybe you should try to disable ipv6 system wide and then check if it works.

Cheers, Robin

...

Hello List, sometime age my msmtp imap connections just stopped working. Investigating the cause, I checked quite a lot of things, and came across the ping "100% package loss" problem:

Thorsten Jolitz via arch-general writes: Hello, following up to my own post:

Marcel Hoppe via arch-general writes:

Hi Marcel, Hi Robin,

thanks for your answers.

...

I resolved the same problem 😉 on my systems I run the networkmanager and this works long time - I'm not sure but I think the problem was that systemd gets or starts its own revolver service. After disabling it and deleting the linked resolve.conf the networkmanager creates it after a restart again and it works.

In Arch it's all about IPv6 it seems, so I did not want to disable it. Instead I deleted the old resolve.conf (it was replaced automatically by systemd). I replaced one (probably wrong) reference to IPv4 with IPv6 in my config, and started and enabled the network service again.

Now pinging works for both protocols, and my internet connection went from incredibly slow to more or less acceptable.

So yesterday it worked, pinging IPv6 adresses as well as having acceptable internet connection speed. Today not anymore, although I did not change anything (ok, wasn't there a kernel update yesterday?) Any help interpreting this messages would be appreciated: ,---- | Jan 28 13:03:58 arch systemd[1]: Timed out waiting for device | sys-subsystem-net-devices-service.device. | -- Subject: Unit sys-subsystem-net-devices-service.device has failed | -- Defined-By: systemd | -- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel | -- | -- Unit sys-subsystem-net-devices-service.device has failed. | -- | -- The result is timeout. | Jan 28 13:03:58 arch systemd[1]: Dependency failed for dhcpcd on | service. | -- Subject: Unit dhcpcd@service.service has failed | -- Defined-By: systemd | -- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel | -- | -- Unit dhcpcd@service.service has failed. | -- | -- The result is dependency. | Jan 28 13:03:58 arch systemd[1]: dhcpcd@service.service: Job | dhcpcd@service.service/start failed with result 'dependency'. `---- Just time out because of lousy internet connecton? ,---- | /run: | -rw-r--r-- 1 root root 5 28. Jan 09:56 dhcpcd.pid `---- ,---- | $ ps 1952 | PID TTY STAT TIME COMMAND | 1952 ? Ss 0:00 dhcpcd `---- At startup, when calling dhcpcd, messages indicate that things worked out, but it seems the service never really started?

PS ,---- | $ ping -c 3 www.google.com | PING www.google.com(waw02s07-in-x04.1e100.net | (2a00:1450:401b:802::2004%2)) 56 data bytes | 64 bytes from waw02s07-in-x04.1e100.net (2a00:1450:401b:802::2004): | icmp_seq=1 ttl=53 time=54.2 ms | 64 bytes from waw02s07-in-x04.1e100.net (2a00:1450:401b:802::2004): | icmp_seq=2 ttl=53 time=49.2 ms | 64 bytes from waw02s07-in-x04.1e100.net (2a00:1450:401b:802::2004): | icmp_seq=3 ttl=53 time=50.2 ms | | --- www.google.com ping statistics --- | 3 packets transmitted, 3 received, 0% packet loss, time 2003ms | rtt min/avg/max/mdev = 49.253/51.266/54.294/2.187 ms `----

,---- | $ ping -c 3 ipv6.google.com | PING ipv6.google.com(waw02s08-in-x0e.1e100.net | (2a00:1450:401b:803::200e%2)) 56 data bytes | 64 bytes from waw02s08-in-x0e.1e100.net (2a00:1450:401b:803::200e): | icmp_seq=1 ttl=53 time=82.3 ms | 64 bytes from waw02s08-in-x0e.1e100.net (2a00:1450:401b:803::200e): | icmp_seq=2 ttl=53 time=48.7 ms | 64 bytes from waw02s08-in-x0e.1e100.net (2a00:1450:401b:803::200e): | icmp_seq=3 ttl=53 time=48.8 ms | | --- ipv6.google.com ping statistics --- | 3 packets transmitted, 3 received, 0% packet loss, time 2003ms | rtt min/avg/max/mdev = 48.754/59.986/82.355/15.819 ms `----

,---- | $ ping -c 3 www.web.de | PING www.g-ha-web.de (82.165.230.17) 56(84) bytes of data. | 64 bytes from bap.web.de (82.165.230.17): icmp_seq=1 ttl=247 time=226 ms | 64 bytes from bap.web.de (82.165.230.17): icmp_seq=2 ttl=247 time=27.8 | ms | 64 bytes from bap.web.de (82.165.230.17): icmp_seq=3 ttl=247 time=27.4 | ms | | --- www.g-ha-web.de ping statistics --- | 3 packets transmitted, 3 received, 0% packet loss, time 2003ms | rtt min/avg/max/mdev = 27.429/93.814/226.124/93.557 ms `----

...

Greets, Marcel

Am 22.01.2017 17:31 schrieb "Robin via arch-general" < arch-general@archlinux.org>:

...

Hi,

seems like a ipv6 related problem. Your DNS Lookup is v4, first ping is v6 and second ping is v4 again. Try to ping the ipv4 address of google.com. But im pretty sure this is not arch related.

Maybe you should try to disable ipv6 system wide and then check if it works.

Cheers, Robin

...

Hello List, sometime age my msmtp imap connections just stopped working. Investigating the cause, I checked quite a lot of things, and came across the ping "100% package loss" problem:

-- cheers, Thorsten

Thorsten Jolitz via arch-general writes: Hello, following up to my own post again.

Thorsten Jolitz via arch-general writes:

Hello, following up to my own post:

...

Marcel Hoppe via arch-general writes:

Hi Marcel, Hi Robin,

thanks for your answers.

...

I resolved the same problem 😉 on my systems I run the networkmanager and this works long time - I'm not sure but I think the problem was that systemd gets or starts its own revolver service. After disabling it and deleting the linked resolve.conf the networkmanager creates it after a restart again and it works.

In Arch it's all about IPv6 it seems, so I did not want to disable it. Instead I deleted the old resolve.conf (it was replaced automatically by systemd). I replaced one (probably wrong) reference to IPv4 with IPv6 in my config, and started and enabled the network service again.

Now pinging works for both protocols, and my internet connection went from incredibly slow to more or less acceptable.

So yesterday it worked, pinging IPv6 adresses as well as having acceptable internet connection speed. Today not anymore, although I did not change anything (ok, wasn't there a kernel update yesterday?)

Any help interpreting this messages would be appreciated: ,---- | Jan 28 13:03:58 arch systemd[1]: Timed out waiting for device | sys-subsystem-net-devices-service.device. | -- Subject: Unit sys-subsystem-net-devices-service.device has failed | -- Defined-By: systemd | -- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel | -- | -- Unit sys-subsystem-net-devices-service.device has failed. | -- | -- The result is timeout. | Jan 28 13:03:58 arch systemd[1]: Dependency failed for dhcpcd on | service. | -- Subject: Unit dhcpcd@service.service has failed | -- Defined-By: systemd | -- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel | -- | -- Unit dhcpcd@service.service has failed. | -- | -- The result is dependency. | Jan 28 13:03:58 arch systemd[1]: dhcpcd@service.service: Job | dhcpcd@service.service/start failed with result 'dependency'. `----

This issue seems to be related to versions of systemd > 230, and I followed the advice in the wiki (adding a custom 'systemd-user-sessions.service' to '/etc/systemd/system/multi-user.target.wants'), and the symptom seems to have gone away. But not so the IPv6 and internet speed problems. I went to all kinds of wiki articles about network configuration, IPv6 and DHCP, and adapted my config in several places to advices from that pages, but to no avail. Now I don't even know how to further diagnose the problem, being unable to ping IPv6 addresses and incredibly slow internet connections seem to be the only visible symptom, everything else looks just fine. And the most surprising thing is, that it worked for one single moment, see the PS, and stopped working after the next reboot - with all what I tried to make it work still untouched and in place. Any further tipps here? TIA

Just time out because of lousy internet connecton?

,---- | /run: | -rw-r--r-- 1 root root 5 28. Jan 09:56 dhcpcd.pid `---- ,---- | $ ps 1952 | PID TTY STAT TIME COMMAND | 1952 ? Ss 0:00 dhcpcd `----

At startup, when calling dhcpcd, messages indicate that things worked out, but it seems the service never really started?

...

PS ,---- | $ ping -c 3 www.google.com | PING www.google.com(waw02s07-in-x04.1e100.net | (2a00:1450:401b:802::2004%2)) 56 data bytes | 64 bytes from waw02s07-in-x04.1e100.net (2a00:1450:401b:802::2004): | icmp_seq=1 ttl=53 time=54.2 ms | 64 bytes from waw02s07-in-x04.1e100.net (2a00:1450:401b:802::2004): | icmp_seq=2 ttl=53 time=49.2 ms | 64 bytes from waw02s07-in-x04.1e100.net (2a00:1450:401b:802::2004): | icmp_seq=3 ttl=53 time=50.2 ms | | --- www.google.com ping statistics --- | 3 packets transmitted, 3 received, 0% packet loss, time 2003ms | rtt min/avg/max/mdev = 49.253/51.266/54.294/2.187 ms `----

,---- | $ ping -c 3 ipv6.google.com | PING ipv6.google.com(waw02s08-in-x0e.1e100.net | (2a00:1450:401b:803::200e%2)) 56 data bytes | 64 bytes from waw02s08-in-x0e.1e100.net (2a00:1450:401b:803::200e): | icmp_seq=1 ttl=53 time=82.3 ms | 64 bytes from waw02s08-in-x0e.1e100.net (2a00:1450:401b:803::200e): | icmp_seq=2 ttl=53 time=48.7 ms | 64 bytes from waw02s08-in-x0e.1e100.net (2a00:1450:401b:803::200e): | icmp_seq=3 ttl=53 time=48.8 ms | | --- ipv6.google.com ping statistics --- | 3 packets transmitted, 3 received, 0% packet loss, time 2003ms | rtt min/avg/max/mdev = 48.754/59.986/82.355/15.819 ms `----

,---- | $ ping -c 3 www.web.de | PING www.g-ha-web.de (82.165.230.17) 56(84) bytes of data. | 64 bytes from bap.web.de (82.165.230.17): icmp_seq=1 ttl=247 | time=226 ms | 64 bytes from bap.web.de (82.165.230.17): icmp_seq=2 ttl=247 time=27.8 | ms | 64 bytes from bap.web.de (82.165.230.17): icmp_seq=3 ttl=247 time=27.4 | ms | | --- www.g-ha-web.de ping statistics --- | 3 packets transmitted, 3 received, 0% packet loss, time 2003ms | rtt min/avg/max/mdev = 27.429/93.814/226.124/93.557 ms `----

...

Greets, Marcel

Am 22.01.2017 17:31 schrieb "Robin via arch-general" < arch-general@archlinux.org>:

...

Hi,

seems like a ipv6 related problem. Your DNS Lookup is v4, first ping is v6 and second ping is v4 again. Try to ping the ipv4 address of google.com. But im pretty sure this is not arch related.

Maybe you should try to disable ipv6 system wide and then check if it works.

Cheers, Robin

...

Hello List, sometime age my msmtp imap connections just stopped working. Investigating the cause, I checked quite a lot of things, and came across the ping "100% package loss" problem:

-- cheers, Thorsten

Damjan Georgievski via arch-general writes:

...

And the most surprising thing is, that it worked for one single moment, see the PS, and stopped working after the next reboot - with all what I tried to make it work still untouched and in place.

Any further tipps here?

do you even have an IPv6 service from your ISP? try pinging [2a00:1450:401b:801::2004] (an address I get for www.google.com)

thats the confusing thing, I more or less randomly end up in one of three situations (without changing anything), trying to ping www.google.com: - IPv6 is tried , but takes forever and has 100% package loss (frecuent). - pinging IPv6 addresses works (very rare) - pinging pure IPv6 addresses (ipv6.google.com) results in 'network not found', but pinging www.google.com results in a successfull IPv4 ping (very rare) So this is just an ISP problem, and the only reasonable solution is to deactivate IPv6 on my system? I'll try that.

also, ping now has the -4 and -6 options to specify which protocol to use. otherwise, AFAIK the resolver in glibc autodetects if it'll use ipv4 or ipv6 by defult

-- cheers, Thorsten

Robin via arch-general writes:

...

- IPv6 is tried , but takes forever and has 100% package loss (frecuent). - pinging IPv6 addresses works (very rare) That's strange. A traceroute with booth working v6 and not working v6 would be helpful. Also a output of your routing table would be nice.

Hi Robin, I remember only one day when IPv6 really worked seamlessly. Today its completely down, so I can only deliver a traceroute with not working v6: ,---- | $ traceroute www.google.com | traceroute to www.google.com (172.217.20.164), 30 hops max, 60 byte | packets | 1 * * * | 2 * * * | 3 * * * | 4 * * * | 5 * 72.14.195.222 (72.14.195.222) 246.613 ms 247.124 ms | 6 108.170.241.195 (108.170.241.195) 249.105 ms * * | 7 216.239.42.70 (216.239.42.70) 40.565 ms 209.85.251.25 | (209.85.251.25) 40.248 ms 108.170.236.140 (108.170.236.140) 39.085 ms | 8 108.170.241.227 (108.170.241.227) 35.108 ms 108.170.241.195 | (108.170.241.195) 40.341 ms 209.85.142.161 (209.85.142.161) 36.544 ms | 9 209.85.143.24 (209.85.143.24) 36.772 ms 209.85.143.27 | (209.85.143.27) 36.526 ms 209.85.143.24 (209.85.143.24) 36.607 ms | 10 209.85.241.98 (209.85.241.98) 58.073 ms 216.239.58.121 | (216.239.58.121) 35.617 ms 216.239.56.17 (216.239.56.17) 35.827 ms | 11 209.85.254.199 (209.85.254.199) 50.322 ms 66.249.95.22 | (66.249.95.22) 83.051 ms 66.249.95.38 (66.249.95.38) 36.208 ms | 12 216.239.41.165 (216.239.41.165) 50.455 ms 216.239.57.241 | (216.239.57.241) 66.627 ms 50.974 ms | 13 209.85.254.157 (209.85.254.157) 49.339 ms | waw02s07-in-f164.1e100.net (172.217.20.164) 52.945 ms 49.656 ms | [tj@arch ~]$ ping www.google.com | PING www.google.com (172.217.20.164) 56(84) bytes of data. | 64 bytes from waw02s07-in-f164.1e100.net (172.217.20.164): icmp_seq=1 | ttl=54 time=93.4 ms | 64 bytes from waw02s07-in-f164.1e100.net (172.217.20.164): icmp_seq=2 | ttl=54 time=50.3 ms | 64 bytes from waw02s07-in-f164.1e100.net (172.217.20.164): icmp_seq=3 | ttl=54 time=49.3 ms | 64 bytes from waw02s07-in-f164.1e100.net (172.217.20.164): icmp_seq=4 | ttl=54 time=51.3 ms | 64 bytes from waw02s07-in-f164.1e100.net (172.217.20.164): icmp_seq=5 | ttl=54 time=49.5 ms | | --- www.google.com ping statistics --- | 5 packets transmitted, 5 received, 0% packet loss, time 4005ms | rtt min/avg/max/mdev = 49.329/58.809/93.484/17.353 ms `---- routing tables: ,---- | $ ip -f inet route show | default via 192.168.2.1 dev ens34 src 192.168.2.122 metric 202 | 192.168.2.0/24 dev ens34 proto kernel scope link src 192.168.2.122 | metric 202 `---- ,---- | $ ip -f inet6 route show | fe80::/64 dev ens34 proto kernel metric 256 pref medium `---- I have a weak WLAN and use a Fritz WLAN Repeater to enhance signal, but this my linux machine has no WLAN card, I plug it by cable into the WLAN repeater ;-)

...

- pinging pure IPv6 addresses (ipv6.google.com) results in 'network not found', but pinging www.google.com results in a successfull IPv4 ping (very rare) What is rare ? The successful v4 ping ?

Yes, because (now I more or less understand what might be happening) normally, v6 is not completely down, so it is tried - and takes forever, pinging with 100 package loss. W3M webbrowsing (using google) still works somehow, but incredibly slow. Today for some reason v6 is completely down, thus v4 is used for www.google.com, and it works (reasonable fast).

This is easy to explain. As far as I know there is only a AAAA record for ipv6.google.com. So when there are any v6 related problem you should not able to send packets to this address. www.google.com got booth an A and and AAAA record. I am not sure how ping decides which protocol to use, but in your case it seems like you v6 network is down (maybe no routing information), so it is using v4. You can force it to use a specific protocol with -4 oder -6 switch.

that explains it very well. ping can be forced to use a certain protocol, but my webbrowser doing google searches (e.g. textbased W3M) seems to always try v6 if its available. -- cheers, Thorsten