[arch-general] NetworkManager warn logs, Is it something to be concerned?
I get these logs in my journal and I am not sure if something is wrong. My wifi works fine though. I have intel card 02:00.0 Network controller [0280]: Intel Corporation Centrino Wireless-N 2200 [8086:0891] (rev c4) my journalctl -r log is [code]Jul 21 22:12:39 archlinux NetworkManager[259]: <warn> (wlp2s0): Lowering IPv6 MTU (1500) to match device MTU (0) Jul 21 22:12:39 archlinux NetworkManager[259]: <warn> (wlp2s0): IPv6 MTU (0) smaller than 1280, adjusting Jul 21 22:12:39 archlinux NetworkManager[259]: <warn> (wlp2s0): Raising device MTU (0) to match IPv6 MTU (1280) Jul 21 22:12:55 archlinux NetworkManager[259]: <warn> (wlp2s0): Lowering IPv6 MTU (1500) to match device MTU (1280) Jul 21 22:13:21 archlinux NetworkManager[259]: <warn> (wlp2s0): Lowering IPv6 MTU (1500) to match device MTU (1280) Jul 21 22:14:13 archlinux NetworkManager[259]: <warn> (wlp2s0): Lowering IPv6 MTU (1500) to match device MTU (1280) Jul 21 22:14:50 archlinux NetworkManager[259]: <warn> (wlp2s0): Lowering IPv6 MTU (1500) to match device MTU (0) Jul 21 22:14:50 archlinux NetworkManager[259]: <warn> (wlp2s0): IPv6 MTU (0) smaller than 1280, adjusting Jul 21 22:14:50 archlinux NetworkManager[259]: <warn> (wlp2s0): Raising device MTU (0) to match IPv6 MTU (1280) Jul 21 22:15:06 archlinux NetworkManager[259]: <warn> (wlp2s0): Lowering IPv6 MTU (1500) to match device MTU (1280) Jul 21 22:15:41 archlinux NetworkManager[259]: <warn> (wlp2s0): Lowering IPv6 MTU (1500) to match device MTU (1280) Jul 21 22:16:02 archlinux NetworkManager[259]: <warn> (wlp2s0): Lowering IPv6 MTU (1500) to match device MTU (1280) Jul 21 22:16:43 archlinux NetworkManager[259]: <warn> (wlp2s0): Lowering IPv6 MTU (1500) to match device MTU (0) Jul 21 22:16:43 archlinux NetworkManager[259]: <warn> (wlp2s0): IPv6 MTU (0) smaller than 1280, adjusting Jul 21 22:16:43 archlinux NetworkManager[259]: <warn> (wlp2s0): Raising device MTU (0) to match IPv6 MTU (1280) Jul 21 22:17:33 archlinux NetworkManager[259]: <warn> (wlp2s0): Lowering IPv6 MTU (1500) to match device MTU (1280) Jul 21 22:17:53 archlinux NetworkManager[259]: <warn> (wlp2s0): Lowering IPv6 MTU (1500) to match device MTU (1280) Jul 21 22:18:26 archlinux NetworkManager[259]: <warn> (wlp2s0): Lowering IPv6 MTU (1500) to match device MTU (1280) Jul 21 22:18:46 archlinux NetworkManager[259]: <warn> (wlp2s0): Lowering IPv6 MTU (1500) to match device MTU (0) Jul 21 22:18:46 archlinux NetworkManager[259]: <warn> (wlp2s0): IPv6 MTU (0) smaller than 1280, adjusting Jul 21 22:18:46 archlinux NetworkManager[259]: <warn> (wlp2s0): Raising device MTU (0) to match IPv6 MTU (1280) Jul 21 22:19:36 archlinux NetworkManager[259]: <warn> (wlp2s0): Lowering IPv6 MTU (1500) to match device MTU (1280) Jul 21 22:20:14 archlinux NetworkManager[259]: <warn> (wlp2s0): Lowering IPv6 MTU (1500) to match device MTU (1280) Jul 21 22:20:52 archlinux NetworkManager[259]: <warn> (wlp2s0): Lowering IPv6 MTU (1500) to match device MTU (0) Jul 21 22:20:52 archlinux NetworkManager[259]: <warn> (wlp2s0): IPv6 MTU (0) smaller than 1280, adjusting Jul 21 22:20:52 archlinux NetworkManager[259]: <warn> (wlp2s0): Raising device MTU (0) to match IPv6 MTU (1280) Jul 21 22:21:30 archlinux NetworkManager[259]: <warn> (wlp2s0): Lowering IPv6 MTU (1500) to match device MTU (1280) Jul 21 22:22:15 archlinux NetworkManager[259]: <warn> (wlp2s0): Lowering IPv6 MTU (1500) to match device MTU (1280) Jul 21 22:22:59 archlinux NetworkManager[259]: <warn> (wlp2s0): Lowering IPv6 MTU (1500) to match device MTU (0) Jul 21 22:22:59 archlinux NetworkManager[259]: <warn> (wlp2s0): IPv6 MTU (0) smaller than 1280, adjusting Jul 21 22:22:59 archlinux NetworkManager[259]: <warn> (wlp2s0): Raising device MTU (0) to match IPv6 MTU (1280) Jul 21 22:23:27 archlinux NetworkManager[259]: <warn> (wlp2s0): Lowering IPv6 MTU (1500) to match device MTU (1280) Jul 21 22:24:23 archlinux NetworkManager[259]: <warn> (wlp2s0): Lowering IPv6 MTU (1500) to match device MTU (1280) Jul 21 22:25:19 archlinux NetworkManager[259]: <warn> (wlp2s0): Lowering IPv6 MTU (1500) to match device MTU (0) Jul 21 22:25:19 archlinux NetworkManager[259]: <warn> (wlp2s0): IPv6 MTU (0) smaller than 1280, adjusting Jul 21 22:25:19 archlinux NetworkManager[259]: <warn> (wlp2s0): Raising device MTU (0) to match IPv6 MTU (1280) Jul 21 22:25:47 archlinux NetworkManager[259]: <warn> (wlp2s0): Lowering IPv6 MTU (1500) to match device MTU (1280) Jul 21 22:26:45 archlinux NetworkManager[259]: <warn> (wlp2s0): Lowering IPv6 MTU (1500) to match device MTU (0) Jul 21 22:26:45 archlinux NetworkManager[259]: <warn> (wlp2s0): IPv6 MTU (0) smaller than 1280, adjusting Jul 21 22:26:45 archlinux NetworkManager[259]: <warn> (wlp2s0): Raising device MTU (0) to match IPv6 MTU (1280) Jul 21 22:27:23 archlinux NetworkManager[259]: <warn> (wlp2s0): Lowering IPv6 MTU (1500) to match device MTU (1280) Jul 21 22:27:44 archlinux NetworkManager[259]: <warn> (wlp2s0): Lowering IPv6 MTU (1500) to match device MTU (1280) Jul 21 22:28:07 archlinux NetworkManager[259]: <warn> (wlp2s0): Lowering IPv6 MTU (1500) to match device MTU (1280) Jul 21 22:28:52 archlinux NetworkManager[259]: <warn> (wlp2s0): Lowering IPv6 MTU (1500) to match device MTU (0) Jul 21 22:28:52 archlinux NetworkManager[259]: <warn> (wlp2s0): IPv6 MTU (0) smaller than 1280, adjusting Jul 21 22:28:52 archlinux NetworkManager[259]: <warn> (wlp2s0): Raising device MTU (0) to match IPv6 MTU (1280) Jul 21 22:29:10 archlinux NetworkManager[259]: <warn> (wlp2s0): Lowering IPv6 MTU (1500) to match device MTU (1280) [/code]
There might be a negligible decrease in speed since 220 bytes less are being transmitted per frame, but I don't think it's a breaking issue. Problems arise when the MTU is set higher than all parts of the network can handle, which is why the standard seems to be 1500 (although I've seen some openvpn configuration files restricting the MTU to 1400 for reducing packet loss -- I've never tested to see if it works or not). I'm not sure why your NIC is broadcasting an MTU of 0. Someone more experienced with the (Arch) Linux network stack should be able to help here.
On Wed, Jul 22, 2015 at 4:00 PM, Christian Demsar <vixsomnis@vczf.io> wrote:
There might be a negligible decrease in speed since 220 bytes less are being transmitted per frame, but I don't think it's a breaking issue. Problems arise when the MTU is set higher than all parts of the network can handle, which is why the standard seems to be 1500 (although I've seen some openvpn configuration files restricting the MTU to 1400 for reducing packet loss -- I've never tested to see if it works or not).
I'm not sure why your NIC is broadcasting an MTU of 0. Someone more experienced with the (Arch) Linux network stack should be able to help here
Thanks christian. I disabled ipv6. It stopped spitting out anymore errors for now. Still can't understand what could have induced this. But I do get errors in thermald in addition. Created an Issue at thermald upstream github. my journalctl -r https://dl.dropboxusercontent.com/u/106654446/journalctl.txt
On 23 July 2015 at 05:33, piruthiviraj natarajan <piruthiviraj@gmail.com> wrote:
On Wed, Jul 22, 2015 at 4:00 PM, Christian Demsar <vixsomnis@vczf.io> wrote:
There might be a negligible decrease in speed since 220 bytes less are being transmitted per frame, but I don't think it's a breaking issue. Problems arise when the MTU is set higher than all parts of the network can handle, which is why the standard seems to be 1500 (although I've seen some openvpn configuration files restricting the MTU to 1400 for reducing packet loss -- I've never tested to see if it works or not).
I'm not sure why your NIC is broadcasting an MTU of 0. Someone more experienced with the (Arch) Linux network stack should be able to help here
Thanks christian. I disabled ipv6. It stopped spitting out anymore errors for now. Still can't understand what could have induced this. But I do get errors in thermald in addition. Created an Issue at thermald upstream github.
my journalctl -r
https://dl.dropboxusercontent.com/u/106654446/journalctl.txt
probably fixed in this commit http://cgit.freedesktop.org/NetworkManager/NetworkManager/commit/src/devices... -- damjan
participants (3)
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Christian Demsar
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Damjan Georgievski
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piruthiviraj natarajan