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89c51

Member

Registered: 2012-06-05

Posts: 741

[Solved]Laptop can't access ipv6 websites on wifi.

... eve thoughtit gets an ip. Also when i test it with a wired connection it works.

The wifi card is:

01:00.0 Network controller: Broadcom Corporation BCM4312 802.11b/g LP-PHY (rev 01)

nmcli dev show
GENERAL.DEVICE:                         wlan0
GENERAL.TYPE:                           wifi
GENERAL.HWADDR:                         00:--:--:--:--:--
GENERAL.MTU:                            0
GENERAL.STATE:                          100 (connected)
GENERAL.CONNECTION:                     name
GENERAL.CON-PATH:                       /org/freedesktop/NetworkManager/ActiveConnection/0
IP4.ADDRESS[1]:                         192.168.1.--/--
IP4.GATEWAY:                            192.168.1.1
IP4.DNS[1]:                             2--.---.---.---
IP4.DNS[2]:                             1--.---.-.-
IP6.ADDRESS[1]:                         2a--:---:----:----:---:---:---:---/64
IP6.ADDRESS[2]:                         2a--:---:----:----:--:----:----:----/128
IP6.ADDRESS[3]:                         fe--::---:----:----:---/64
IP6.GATEWAY:                            fe--::---:----:----:----
IP6.ROUTE[1]:                           dst = 2a--:---:----:----::/64, nh = ::, mt = 600
IP6.ROUTE[2]:                           dst = fe--::---:----:----:----/128, nh = ::, mt = 600
IP6.DNS[1]:                             2a--:---:---:--:---:---:---:---
IP6.DNS[2]:                             2a--:---:---:--:---:---:--:--

GENERAL.DEVICE:                         enp2s0
GENERAL.TYPE:                           ethernet
GENERAL.HWADDR:                         00:--:--:--:--:--
GENERAL.MTU:                            1500
GENERAL.STATE:                          20 (unavailable)
GENERAL.CONNECTION:                     --
GENERAL.CON-PATH:                       --
WIRED-PROPERTIES.CARRIER:               off

GENERAL.DEVICE:                         lo
GENERAL.TYPE:                           loopback
GENERAL.HWADDR:                         00:00:00:00:00:00
GENERAL.MTU:                            65536
GENERAL.STATE:                          10 (unmanaged)
GENERAL.CONNECTION:                     --
GENERAL.CON-PATH:                       --
IP4.ADDRESS[1]:                         127.0.0.1/8
IP4.GATEWAY:                            
IP6.ADDRESS[1]:                         ::1/128
IP6.GATEWAY:        

MTU 0 ???????

Other devices i tested (one android and one Sailfish phone) work ok with ipv6 so it isn't a problem with the router.

On the journal i see:

Aug 12 21:36:11 testland NetworkManager[318]: <warn>  (wlan0): Lowering IPv6 MTU (1492) to match device MTU (0)
Aug 12 21:36:11 testland NetworkManager[318]: <warn>  (wlan0): IPv6 MTU (0) smaller than 1280, adjusting
Aug 12 21:36:11 testland NetworkManager[318]: <warn>  (wlan0): Raising device MTU (0) to match IPv6 MTU (1280)
Aug 12 21:36:11 testland NetworkManager[318]: <error> [1439404571.317703] [platform/nm-linux-platform.c:2440] sysctl_set(): platform-linux: sysctl: failed to set '/proc/sys/net/ipv6/conf/wlan0/mtu' to '1492': (22) Invalid argument

and many messages like:

Aug 12 21:40:09 testland NetworkManager[318]: <warn>  (wlan0): Lowering IPv6 MTU (1492) to match device MTU (0)
Aug 12 21:40:09 testland NetworkManager[318]: <warn>  (wlan0): IPv6 MTU (0) smaller than 1280, adjusting
Aug 12 21:40:09 testland NetworkManager[318]: <warn>  (wlan0): Raising device MTU (0) to match IPv6 MTU (1280)
Aug 12 21:44:27 testland NetworkManager[318]: <warn>  (wlan0): Lowering IPv6 MTU (1492) to match device MTU (0)
Aug 12 21:44:27 testland NetworkManager[318]: <warn>  (wlan0): IPv6 MTU (0) smaller than 1280, adjusting
Aug 12 21:44:27 testland NetworkManager[318]: <warn>  (wlan0): Raising device MTU (0) to match IPv6 MTU (1280)
Aug 12 21:44:53 testland NetworkManager[318]: <warn>  (wlan0): Lowering IPv6 MTU (1492) to match device MTU (1280)
Aug 12 21:45:41 testland NetworkManager[318]: <warn>  (wlan0): Lowering IPv6 MTU (1492) to match device MTU (1280)

driver bug, kernel bug or what??

Last edited by 89c51 (2015-08-13 17:08:52)

Techmeology

Member

Registered: 2012-08-21

Posts: 19

Re: [Solved]Laptop can't access ipv6 websites on wifi.

IPv6 has a minimum MTU of 1280 octets (bytes). IPv4, on the other hand, has a minimum MTU of just 68 octets. So it's possible your wifi card simply doesn't have a big enough MTU.

ip link

should tell you what the MTU is. If the MTU is large enough, try to find where the packets are lost.

What happens if you run something like:

$ traceroute -6 google.com

What happens if you run

ping6 $GATEWAY

Last edited by Techmeology (2015-08-13 12:32:47)

89c51

Member

Registered: 2012-06-05

Posts: 741

Re: [Solved]Laptop can't access ipv6 websites on wifi.

Just tested this whole thing again right now and the damn thing works fine.

Yesterdays i spend hours trying to find if there was something wrong.

I still get stuff like:

Aug 13 20:06:17 testland NetworkManager[319]: <warn>  (wlan0): Lowering IPv6 MTU (1492) to match device MTU (0)
Aug 13 20:06:17 testland NetworkManager[319]: <warn>  (wlan0): IPv6 MTU (0) smaller than 1280, adjusting
Aug 13 20:06:17 testland NetworkManager[319]: <warn>  (wlan0): Raising device MTU (0) to match IPv6 MTU (1280)
Aug 13 20:06:17 testland NetworkManager[319]: <error> [1439485577.039520] [platform/nm-linux-platform.c:2440] sysctl_set(): platform-linux: sysctl: failed to set '/proc/sys/net/ipv6/conf/wlan0/mtu' to '1492': (22)

but i can do ipv6 stuff (mosh ping6 traceroute).

Sorry for the fuss and thanks @Techmeology .