Discussion:
Ping: 100% package loss
(too old to reply)
Thorsten Jolitz via arch-general
2017-01-22 15:58:10 UTC
Permalink
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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:

With

/etc/resolv.conf
,----
| # Generated by resolvconf
| domain Speedport_W_xxxxxx
|
| nameserver 192.168.2.1
| nameserver fe80::1%ens34
`----

this works

,----
| $ drill @192.168.2.1. www.google.com
| ;; ->>HEADER<<- opcode: QUERY, rcode: NOERROR, id: 36946
| ;; flags: qr rd ra ; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0
| ;; QUESTION SECTION:
| ;; www.google.com. IN A
|
| ;; ANSWER SECTION:
| www.google.com. 39 IN A 216.58.210.196
|
| ;; AUTHORITY SECTION:
|
| ;; ADDITIONAL SECTION:
|
| ;; Query time: 4 msec
| ;; SERVER: 192.168.2.1
| ;; WHEN: Sun Jan 22 15:53:08 2017
| ;; MSG SIZE rcvd: 48
`----

but this not
,----
| $ ping -c 3 www.google.com
| PING www.google.com(mrs04s09-in-x04.1e100.net
| (2a00:1450:4006:803::2004)) 56 data bytes
|
| --- www.google.com ping statistics ---
| 3 packets transmitted, 0 received, 100% packet loss, time 2014ms
`----

Network connectivity is obviously given
,----
| [***@arch ~]$ ping -c 3 216.58.210.196
| PING 216.58.210.196 (216.58.210.196) 56(84) bytes of data.
| 64 bytes from 216.58.210.196: icmp_seq=1 ttl=54 time=51.4 ms
| 64 bytes from 216.58.210.196: icmp_seq=2 ttl=54 time=49.8 ms
| 64 bytes from 216.58.210.196: icmp_seq=3 ttl=54 time=50.7 ms
|
| --- 216.58.210.196 ping statistics ---
| 3 packets transmitted, 3 received, 0% packet loss, time 2003ms
| rtt min/avg/max/mdev = 49.855/50.685/51.408/0.689 ms
`----

and I can ping the nameserver ip too.

Even when I put Googles DNS Servers in my /etc/resolv.conf, it would not
work.
So what could be the problem here?

TIA
--
cheers,
Thorsten
Robin via arch-general
2017-01-22 16:31:41 UTC
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Raw Message
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
Post by Thorsten Jolitz via arch-general
Hello List,
sometime age my msmtp imap connections just stopped working.
Investigating the cause, I checked quite a lot of things, and came
Marcel Hoppe via arch-general
2017-01-22 17:20:29 UTC
Permalink
Raw Message
Hi,

I resolved the same problem πŸ˜‰ 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" <
Post by Robin via arch-general
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
Post by Thorsten Jolitz via arch-general
Hello List,
sometime age my msmtp imap connections just stopped working.
Investigating the cause, I checked quite a lot of things, and came
Thorsten Jolitz via arch-general
2017-01-26 22:14:57 UTC
Permalink
Raw Message
Marcel Hoppe via arch-general <arch-***@archlinux.org> writes:

Hi Marcel, Hi Robin,

thanks for your answers.
Post by Marcel Hoppe via arch-general
I resolved the same problem πŸ˜‰ 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.

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
`----
Post by Marcel Hoppe via arch-general
Greets,
Marcel
Am 22.01.2017 17:31 schrieb "Robin via arch-general" <
Post by Robin via arch-general
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
Post by Thorsten Jolitz via arch-general
Hello List,
sometime age my msmtp imap connections just stopped working.
Investigating the cause, I checked quite a lot of things, and came
--
cheers,
Thorsten
Thorsten Jolitz via arch-general
2017-01-28 12:17:14 UTC
Permalink
Raw Message
Thorsten Jolitz via arch-general <arch-***@archlinux.org> writes:

Hello,
Post by Thorsten Jolitz via arch-general
Hi Marcel, Hi Robin,
thanks for your answers.
Post by Marcel Hoppe via arch-general
I resolved the same problem πŸ˜‰ 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 ***@service.service has failed
| -- Defined-By: systemd
| -- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
| --
| -- Unit ***@service.service has failed.
| --
| -- The result is dependency.
| Jan 28 13:03:58 arch systemd[1]: ***@service.service: Job
| ***@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?
Post by Thorsten Jolitz via arch-general
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
| icmp_seq=1 ttl=53 time=54.2 ms
| icmp_seq=2 ttl=53 time=49.2 ms
| 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
| icmp_seq=1 ttl=53 time=82.3 ms
| icmp_seq=2 ttl=53 time=48.7 ms
| 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
`----
Post by Marcel Hoppe via arch-general
Greets,
Marcel
Am 22.01.2017 17:31 schrieb "Robin via arch-general" <
Post by Robin via arch-general
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
Post by Thorsten Jolitz via arch-general
Hello List,
sometime age my msmtp imap connections just stopped working.
Investigating the cause, I checked quite a lot of things, and came
--
cheers,
Thorsten
Thorsten Jolitz via arch-general
2017-01-28 12:17:01 UTC
Permalink
Raw Message
Thorsten Jolitz via arch-general <arch-***@archlinux.org> writes:

Hello,
Post by Thorsten Jolitz via arch-general
Hi Marcel, Hi Robin,
thanks for your answers.
Post by Marcel Hoppe via arch-general
I resolved the same problem πŸ˜‰ 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 ***@service.service has failed
| -- Defined-By: systemd
| -- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
| --
| -- Unit ***@service.service has failed.
| --
| -- The result is dependency.
| Jan 28 13:03:58 arch systemd[1]: ***@service.service: Job
| ***@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?
Post by Thorsten Jolitz via arch-general
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
| icmp_seq=1 ttl=53 time=54.2 ms
| icmp_seq=2 ttl=53 time=49.2 ms
| 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
| icmp_seq=1 ttl=53 time=82.3 ms
| icmp_seq=2 ttl=53 time=48.7 ms
| 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
`----
Post by Marcel Hoppe via arch-general
Greets,
Marcel
Am 22.01.2017 17:31 schrieb "Robin via arch-general" <
Post by Robin via arch-general
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
Post by Thorsten Jolitz via arch-general
Hello List,
sometime age my msmtp imap connections just stopped working.
Investigating the cause, I checked quite a lot of things, and came
--
cheers,
Thorsten
Thorsten Jolitz via arch-general
2017-01-29 13:25:02 UTC
Permalink
Raw Message
Thorsten Jolitz via arch-general <arch-***@archlinux.org> writes:

Hello,
following up to my own post again.
Post by Thorsten Jolitz via arch-general
Hello,
Post by Thorsten Jolitz via arch-general
Hi Marcel, Hi Robin,
thanks for your answers.
Post by Marcel Hoppe via arch-general
I resolved the same problem πŸ˜‰ 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?)
,----
| 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.
| -- Defined-By: systemd
| -- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
| --
| --
| -- The result is 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
Post by Thorsten Jolitz via arch-general
Just time out because of lousy internet connecton?
,----
| -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?
Post by Thorsten Jolitz via arch-general
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
| icmp_seq=1 ttl=53 time=54.2 ms
| icmp_seq=2 ttl=53 time=49.2 ms
| 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
| icmp_seq=1 ttl=53 time=82.3 ms
| icmp_seq=2 ttl=53 time=48.7 ms
| 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
`----
Post by Marcel Hoppe via arch-general
Greets,
Marcel
Am 22.01.2017 17:31 schrieb "Robin via arch-general" <
Post by Robin via arch-general
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
Post by Thorsten Jolitz via arch-general
Hello List,
sometime age my msmtp imap connections just stopped working.
Investigating the cause, I checked quite a lot of things, and came
--
cheers,
Thorsten
Damjan Georgievski via arch-general
2017-01-29 22:19:26 UTC
Permalink
Raw Message
Post by Thorsten Jolitz via arch-general
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)

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
--
damjan
Thorsten Jolitz via arch-general
2017-02-02 18:12:28 UTC
Permalink
Raw Message
Post by Damjan Georgievski via arch-general
Post by Thorsten Jolitz via arch-general
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.
Post by Damjan Georgievski via arch-general
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
2017-02-02 18:47:14 UTC
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Post by Thorsten Jolitz via arch-general
- 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.
Post by Thorsten Jolitz via arch-general
- 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 ?
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.
Thorsten Jolitz via arch-general
2017-02-02 19:56:44 UTC
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Post by Robin via arch-general
Post by Thorsten Jolitz via arch-general
- 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
| [***@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 ;-)
Post by Robin via arch-general
Post by Thorsten Jolitz via arch-general
- 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).
Post by Robin via arch-general
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
Guus Snijders via arch-general
2017-02-02 21:26:58 UTC
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Op 2 feb. 2017 20:58 schreef "Thorsten Jolitz via arch-general" <
Post by Thorsten Jolitz via arch-general
- IPv6 is tried , but takes forever and has 100% package loss
(frecuent).
- pinging IPv6 addresses works (very rare)
[...]
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.


Which just leaves the question: do you want to use IPv6 or do you prefer
IPv4?

In the first case, perhaps a tunnel provider can help as your current setup
appears flaky at best. In the second case, it's probably better to find out
how to disable IPv6 on your machine.


Mvg, Guus Snijders
Thorsten Jolitz via arch-general
2017-02-02 21:52:28 UTC
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Post by Guus Snijders via arch-general
Op 2 feb. 2017 20:58 schreef "Thorsten Jolitz via arch-general" <
In the first case, perhaps a tunnel provider can help as your current setup
appears flaky at best. In the second case, it's probably better to find out
how to disable IPv6 on your machine.
The second case seems the way to go, there are even related wiki
articles about disabling IPv6.
Took a while to understand whats going on ...
--
cheers,
Thorsten
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