networkmanager creates interface "lo" (probably local?)
what is the meaning of the "lo" interface that appeared on my networkmanager. I also looked what is about wicked but for some reasons wicked seems gone? Not really understanding, I did not see any update that required to uninstall wicked. Anybody knows what is the use of "lo" and what is going on?
lo == loopback interface. Ken Schneider
On Feb 16, 2023, at 5:56 PM, Stakanov <stakanov@disroot.org> wrote:
what is the meaning of the "lo" interface that appeared on my networkmanager. I also looked what is about wicked but for some reasons wicked seems gone?
Not really understanding, I did not see any update that required to uninstall wicked.
Anybody knows what is the use of "lo" and what is going on?
In data venerdì 17 febbraio 2023 00:13:01 CET, kschneider bout-tyme. net ha scritto:
lo == loopback interface.
Ken Schneider
On Feb 16, 2023, at 5:56 PM, Stakanov <stakanov@disroot.org> wrote:
what is the meaning of the "lo" interface that appeared on my networkmanager. I also looked what is about wicked but for some reasons wicked seems gone? Not really understanding, I did not see any update that required to uninstall wicked.
Anybody knows what is the use of "lo" and what is going on?
well, I am still troubled, because I simply do not understand why the lo was not present before and now it appeared. I am also having problems with my network setup. The usecase of lo in my PC is not something I would expect to request the presence of an lo. But since another instance I have of TW also shows now a lo interface, I think this was an update that made it appear. I am just not understanding to what purpose.
On 2023-02-17 02:06, Stakanov wrote:
In data venerdì 17 febbraio 2023 00:13:01 CET, kschneider bout-tyme. net ha scritto:
lo == loopback interface.
...
Anybody knows what is the use of "lo" and what is going on?
well, I am still troubled, because I simply do not understand why the lo was not present before and now it appeared. I am also having problems with my network setup. The usecase of lo in my PC is not something I would expect to request the presence of an lo. But since another instance I have of TW also shows now a lo interface, I think this was an update that made it appear. I am just not understanding to what purpose.
I see "lo" since ever. Decades ago. cer@Telcontar:~> ifconfig eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 192.168.1.14 netmask 255.255.0.0 broadcast 192.168.255.255 inet6 fe80::2d8:... prefixlen 64 scopeid 0x20<link> ether 00:d8:61:a1:5a:bd txqueuelen 1000 (Ethernet) RX packets 1918666 bytes 1387107591 (1.2 GiB) RX errors 0 dropped 3470 overruns 0 frame 0 TX packets 1469968 bytes 250810218 (239.1 MiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536 inet 127.0.0.1 netmask 255.0.0.0 inet6 ::1 prefixlen 128 scopeid 0x10<host> loop txqueuelen 1000 (Local Loopback) RX packets 1071607 bytes 177021090 (168.8 MiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 1071607 bytes 177021090 (168.8 MiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 cer@Telcontar:~> -- Cheers / Saludos, Carlos E. R. (from 15.4 x86_64 at Telcontar)
On 2/16/2023 8:06 PM, Stakanov wrote:
In data venerdì 17 febbraio 2023 00:13:01 CET, kschneider bout-tyme. net ha scritto:
lo == loopback interface.
Ken Schneider
On Feb 16, 2023, at 5:56 PM, Stakanov <stakanov@disroot.org> wrote:
what is the meaning of the "lo" interface that appeared on my networkmanager. I also looked what is about wicked but for some reasons wicked seems gone? Not really understanding, I did not see any update that required to uninstall wicked.
Anybody knows what is the use of "lo" and what is going on?
well, I am still troubled, because I simply do not understand why the lo was not present before and now it appeared. I am also having problems with my network setup. The usecase of lo in my PC is not something I would expect to request the presence of an lo. But since another instance I have of TW also shows now a lo interface, I think this was an update that made it appear. I am just not understanding to what purpose.
Far as I know lo is always there. It is used for many things by default and to try and get rid of it is likely to break things. If you have a system that does not show it, try "ping 127.0.0.1" and you should get a response. "ping localhost" should also return response Sorry that does not help much.
Stakanov wrote:
well, I am still troubled, because I simply do not understand why the lo was not present before and now it appeared. I am also having problems with my network setup. The usecase of lo in my PC is not something I would expect to request the presence of an lo. But since another instance I have of TW also shows now a lo interface, I think this was an update that made it appear. I am just not understanding to what purpose.
AFAICT, networkmanager was enhanced to also manage the loopback interface (for instance adding addresses to it), that's really all. Your systems have _always_ had a loopback interface, but networkmanager didn't "support" it. Now it does. -- Per Jessen, Zürich (11.5°C) Member, openSUSE Heroes (2016 - present) We're hiring - https://en.opensuse.org/openSUSE:Heroes
In data venerdì 17 febbraio 2023 09:18:35 CET, Per Jessen ha scritto:
Stakanov wrote:
well, I am still troubled, because I simply do not understand why the lo was not present before and now it appeared. I am also having problems with my network setup. The usecase of lo in my PC is not something I would expect to request the presence of an lo. But since another instance I have of TW also shows now a lo interface, I think this was an update that made it appear. I am just not understanding to what purpose.
AFAICT, networkmanager was enhanced to also manage the loopback interface (for instance adding addresses to it), that's really all. Your systems have _always_ had a loopback interface, but networkmanager didn't "support" it. Now it does. Yeap, this is the answer to my question, since Networkmanager did suddenly show it (I know of course about loopback but I did not recall any change that could have induced a change in network manager applets behavior.
Thank you, this is hence the reason for the "miracle"
Am Freitag, 17. Februar 2023, 10:04:24 CET schrieb Stakanov: (...)
Yeap, this is the answer to my question, since Networkmanager did suddenly show it (I know of course about loopback but I did not recall any change that could have induced a change in network manager applets behavior.
Same here.
Thank you, this is hence the reason for the "miracle"
Came to a surprise for me,too :-) -- Best Regards - Mit freundlichen Grüßen, Markus Feilner, Feilner IT - 20 years of open services - Sustainable Open Source Strategy, Networking, Politics, Journalism Knowledge Management, Rubber Ducks, Trainings, Workshops, Documentation https://www.feilner-it.net, 93059 Regensburg Wöhrdstr. 10, +49 170 302 7092 (+Signal) https://mastodon.cloud/@mfeilner https://mastodon.social/@FeilnerIT PGP: 40A3C306F96133067C11CFD9A958A906268C9F0A http://www.feilner-it.net/files/MFpub.asc Xing: http://www.xing.com/profile/Markus_Feilner LinkedIn: https://www.linkedin.com/in/markusfeilner @mfeilner: Mastodon, Matrix, Jabber, ...
On 17.02.2023 01:55, Stakanov wrote:
what is the meaning of the "lo" interface that appeared on my networkmanager.
https://networkmanager.dev/blog/networkmanager-1-42/ And scroll to the Managing the loopback interface.
I also looked what is about wicked but for some reasons wicked seems gone?
Not really understanding, I did not see any update that required to uninstall wicked.
Anybody knows what is the use of "lo" and what is going on?
In data venerdì 17 febbraio 2023 05:10:19 CET, Andrei Borzenkov ha scritto:
On 17.02.2023 01:55, Stakanov wrote:
what is the meaning of the "lo" interface that appeared on my networkmanager. https://networkmanager.dev/blog/networkmanager-1-42/
And scroll to the Managing the loopback interface.
I also looked what is about wicked but for some reasons wicked seems gone?
Not really understanding, I did not see any update that required to uninstall wicked.
Anybody knows what is the use of "lo" and what is going on? Thank you, and this was a supplemental interesting reading.
I have to admit that I struggle to see if it is a usecase for me or not.
With the loopback interface always guaranteed to exist in one instance, a connection on a loopback interface can be used to specify configuration that’s always supposed to be applied. This includes things like adding an extra IP address or perhaps a DNS server.
Humm, not that I am very good in networking but as far as I understand what is written the use of lo is a kind of constituting a "template"? I find the new behavior a bit confusing. Before I had the ethernet cabled connection set up without IP to be used via the bridge (and that bridge would then serve and is necessary to me, as interface for my KVM virtual machines. Now however I have the loopback interface that is always there and always connected....to 127.0.0.1 but...my cabled ethernet connection is not shown anymore in the list, only lo and br0. And to make it more curious when I hover over the symbol of the Network manager in the tray, I DO(!) see three cabled ethernet lo, cabled ethernet enp7s0 and br0 interfaces. But not in the list of interfaces when I open it, there just lo and br0 Is this intentional? (If you happen to know of course).
On 18.02.2023 03:05, Stakanov wrote:
In data venerdì 17 febbraio 2023 05:10:19 CET, Andrei Borzenkov ha scritto:
On 17.02.2023 01:55, Stakanov wrote:
what is the meaning of the "lo" interface that appeared on my networkmanager. https://networkmanager.dev/blog/networkmanager-1-42/
And scroll to the Managing the loopback interface.
I also looked what is about wicked but for some reasons wicked seems gone?
Not really understanding, I did not see any update that required to uninstall wicked.
Anybody knows what is the use of "lo" and what is going on? Thank you, and this was a supplemental interesting reading.
I have to admit that I struggle to see if it is a usecase for me or not.
With the loopback interface always guaranteed to exist in one instance, a connection on a loopback interface can be used to specify configuration that’s always supposed to be applied. This includes things like adding an extra IP address or perhaps a DNS server.
Humm, not that I am very good in networking but as far as I understand what is written the use of lo is a kind of constituting a "template"?
I find the new behavior a bit confusing. Before I had the ethernet cabled connection set up without IP to be used via the bridge (and that bridge would then serve and is necessary to me, as interface for my KVM virtual machines.
Now however I have the loopback interface that is always there and always connected....to 127.0.0.1 but...my cabled ethernet connection is not shown anymore in the list, only lo and br0. And to make it more curious when I hover over the symbol of the Network manager in the tray, I DO(!) see three cabled ethernet lo, cabled ethernet enp7s0 and br0 interfaces. But not in the list of interfaces when I open it, there just lo and br0
Is this intentional? (If you happen to know of course).
No idea. You do not even tell what desktop environment you are using or what program is behind "symbol of the Network manager". Show output of LANGUAGE=C PAGER= nmcli device LANGUAGE=C PAGER= nmcli connection
In data sabato 18 febbraio 2023 07:15:25 CET, Andrei Borzenkov ha scritto:
On 18.02.2023 03:05, Stakanov wrote:
In data venerdì 17 febbraio 2023 05:10:19 CET, Andrei Borzenkov ha scritto:
On 17.02.2023 01:55, Stakanov wrote:
what is the meaning of the "lo" interface that appeared on my networkmanager.
https://networkmanager.dev/blog/networkmanager-1-42/
And scroll to the Managing the loopback interface.
I also looked what is about wicked but for some reasons wicked seems gone?
Not really understanding, I did not see any update that required to uninstall wicked.
Anybody knows what is the use of "lo" and what is going on?
Thank you, and this was a supplemental interesting reading.
I have to admit that I struggle to see if it is a usecase for me or not.
With the loopback interface always guaranteed to exist in one instance, a connection on a loopback interface can be used to specify configuration that’s always supposed to be applied. This includes things like adding an extra IP address or perhaps a DNS server.
Humm, not that I am very good in networking but as far as I understand what is written the use of lo is a kind of constituting a "template"?
I find the new behavior a bit confusing. Before I had the ethernet cabled connection set up without IP to be used via the bridge (and that bridge would then serve and is necessary to me, as interface for my KVM virtual machines.
Now however I have the loopback interface that is always there and always connected....to 127.0.0.1 but...my cabled ethernet connection is not shown anymore in the list, only lo and br0. And to make it more curious when I hover over the symbol of the Network manager in the tray, I DO(!) see three cabled ethernet lo, cabled ethernet enp7s0 and br0 interfaces. But not in the list of interfaces when I open it, there just lo and br0
Is this intentional? (If you happen to know of course).
No idea. You do not even tell what desktop environment you are using or what program is behind "symbol of the Network manager".
Show output of
LANGUAGE=C PAGER= nmcli device LANGUAGE=C PAGER= nmcli connection
entropy@localhost:~> LANGUAGE=C PAGER= nmcli device DEVICE TYPE STATE CONNECTION br1 bridge connected br1 lo loopback connected (externally) lo enp7s0 ethernet connected enp7s0 br1 061ef80f-f74b-3e4c-bd33-b4af9a4ab0ca bridge br1 lo ad2a8122-d824-4459-8b33-927bff6595da loopback lo enp7s0 8ed855e5-8e0a-3c75-ba6c-c2bca7c86f32 ethernet enp7s0 br0 dd45b56c-398d-4539-8369-aa6199c0df7f bridge -- enp8s0 c9325210-a630-39f4-a1d8-2ea015bf274a ethernet -- Operating System: openSUSE Tumbleweed 20230217 KDE Plasma Version: 5.27.0 KDE Frameworks Version: 5.103.0 Qt Version: 5.15.8 Kernel Version: 6.1.12-1-default (64-bit) Graphics Platform: X11 Processors: 4 × AMD FX(tm)-4300 Quad-Core Processor Memory: 31.3 GiB of RAM Graphics Processor: AMD Radeon Pro W5500 Manufacturer: Gigabyte Technology Co., Ltd. The symbol in the tray is the "nmapplet" showing in Plasma as "networkmanagerapplet" in the tray. enp7s0 ethernet connected enp7s0 did show in the connection window of the applet before, but since the upgrade it does not. What means "externally connected" in relation with lo? I thought this is just locally connected?
Stakanov wrote:
What means "externally connected" in relation with lo? I thought this is just locally connected?
It isn't "connected" at all, but for the interface to be up, it has to be faked. The loopback interface is a very special case. -- Per Jessen, Zürich (13.4°C) Member, openSUSE Heroes (2016 - present) We're hiring - https://en.opensuse.org/openSUSE:Heroes
On 18.02.2023 18:41, Stakanov wrote: ...
And to make it more curious when I hover over the symbol of the Network manager in the tray, I DO(!) see three cabled ethernet lo, cabled ethernet enp7s0 and br0 interfaces. But not in the list of interfaces when I open it, there just lo and br0
Is this intentional? (If you happen to know of course).
No idea. You do not even tell what desktop environment you are using or what program is behind "symbol of the Network manager".
Show output of
LANGUAGE=C PAGER= nmcli device LANGUAGE=C PAGER= nmcli connection
entropy@localhost:~> LANGUAGE=C PAGER= nmcli device DEVICE TYPE STATE CONNECTION br1 bridge connected br1 lo loopback connected (externally) lo enp7s0 ethernet connected enp7s0
br1 061ef80f-f74b-3e4c-bd33-b4af9a4ab0ca bridge br1 lo ad2a8122-d824-4459-8b33-927bff6595da loopback lo enp7s0 8ed855e5-8e0a-3c75-ba6c-c2bca7c86f32 ethernet enp7s0 br0 dd45b56c-398d-4539-8369-aa6199c0df7f bridge -- enp8s0 c9325210-a630-39f4-a1d8-2ea015bf274a ethernet --
Operating System: openSUSE Tumbleweed 20230217 KDE Plasma Version: 5.27.0 KDE Frameworks Version: 5.103.0 Qt Version: 5.15.8 Kernel Version: 6.1.12-1-default (64-bit) Graphics Platform: X11 Processors: 4 × AMD FX(tm)-4300 Quad-Core Processor Memory: 31.3 GiB of RAM Graphics Processor: AMD Radeon Pro W5500 Manufacturer: Gigabyte Technology Co., Ltd.
The symbol in the tray is the "nmapplet" showing in Plasma as "networkmanagerapplet" in the tray. enp7s0 ethernet connected enp7s0
As far as I can tell, tool tip shows active connection profiles and when you open applet it shows "filtered" connection profiles - you are not supposed to manage bridge slave directly (from the Plasma applet developers PoV) so applet hides it. When connection profiles are named like interfaces it becomes rather confusing. Of course showing "Wired Ethernet: connected to lo" is wrong - "lo" has type "loopback", not "Ethernet". But Plasma applet is not part of NetworkManager; it is completely separate project. So no wonder it lags behind NetworkManager changes. You may consider opening bug report on KDE bugtracker. Also strictly speaking "connected to bridge" is inaccurate as well - for virtual interfaces they are created as part of profile activation, there is nothing to "connect to" before profile is active. It were also more useful to show actual interface names ... and so on, there is certainlyroom for improvement.
did show in the connection window of the applet before, but since the upgrade it does not.
What means "externally connected" in relation with lo?
It means that NetworkManager adopted interface configuration that existed when NetworkManager was started; it was not actively configured by NetworkManager itself.
I thought this is just locally connected?
In data sabato 18 febbraio 2023 19:56:18 CET, Andrei Borzenkov ha scritto:
On 18.02.2023 18:41, Stakanov wrote: ...
And to make it more curious when I hover over the symbol of the Network manager in the tray, I DO(!) see three cabled ethernet lo, cabled ethernet enp7s0 and br0 interfaces. But not in the list of interfaces when I open it, there just lo and br0
Is this intentional? (If you happen to know of course).
No idea. You do not even tell what desktop environment you are using or what program is behind "symbol of the Network manager".
Show output of
LANGUAGE=C PAGER= nmcli device LANGUAGE=C PAGER= nmcli connection
entropy@localhost:~> LANGUAGE=C PAGER= nmcli device DEVICE TYPE STATE CONNECTION br1 bridge connected br1 lo loopback connected (externally) lo enp7s0 ethernet connected enp7s0
br1 061ef80f-f74b-3e4c-bd33-b4af9a4ab0ca bridge br1 lo ad2a8122-d824-4459-8b33-927bff6595da loopback lo enp7s0 8ed855e5-8e0a-3c75-ba6c-c2bca7c86f32 ethernet enp7s0 br0 dd45b56c-398d-4539-8369-aa6199c0df7f bridge -- enp8s0 c9325210-a630-39f4-a1d8-2ea015bf274a ethernet --
Operating System: openSUSE Tumbleweed 20230217 KDE Plasma Version: 5.27.0 KDE Frameworks Version: 5.103.0 Qt Version: 5.15.8 Kernel Version: 6.1.12-1-default (64-bit) Graphics Platform: X11 Processors: 4 × AMD FX(tm)-4300 Quad-Core Processor Memory: 31.3 GiB of RAM Graphics Processor: AMD Radeon Pro W5500 Manufacturer: Gigabyte Technology Co., Ltd.
The symbol in the tray is the "nmapplet" showing in Plasma as "networkmanagerapplet" in the tray. enp7s0 ethernet connected enp7s0
As far as I can tell, tool tip shows active connection profiles and when you open applet it shows "filtered" connection profiles - you are not supposed to manage bridge slave directly (from the Plasma applet developers PoV) so applet hides it. When connection profiles are named like interfaces it becomes rather confusing.
Of course showing "Wired Ethernet: connected to lo" is wrong - "lo" has type "loopback", not "Ethernet". But Plasma applet is not part of NetworkManager; it is completely separate project. So no wonder it lags behind NetworkManager changes. You may consider opening bug report on KDE bugtracker.
Also strictly speaking "connected to bridge" is inaccurate as well - for virtual interfaces they are created as part of profile activation, there is nothing to "connect to" before profile is active. It were also more useful to show actual interface names ... and so on, there is certainlyroom for improvement.
did show in the connection window of the applet before, but since the upgrade it does not.
What means "externally connected" in relation with lo?
It means that NetworkManager adopted interface configuration that existed when NetworkManager was started; it was not actively configured by NetworkManager itself.
I thought this is just locally connected?
Kind of you. Thank you very helpful. I will need to deepen my understanding of network structures. Feeling like a hamster, for every bit you learn the wheel turns.....
Am Samstag, 18. Februar 2023, 19:56:18 CET schrieb Andrei Borzenkov:
It means that NetworkManager adopted interface configuration that existed when NetworkManager was started; it was not actively configured by NetworkManager itself.
I thought this is just locally connected?
Correct, and it makes on sense that it is being displayed. -- Best Regards - Mit freundlichen Grüßen, Markus Feilner, Feilner IT - 20 years of open services - Sustainable Open Source Strategy, Networking, Politics, Journalism Knowledge Management, Rubber Ducks, Trainings, Workshops, Documentation https://www.feilner-it.net, 93059 Regensburg Wöhrdstr. 10, +49 170 302 7092 (+Signal) https://mastodon.cloud/@mfeilner https://mastodon.social/@FeilnerIT PGP: 40A3C306F96133067C11CFD9A958A906268C9F0A http://www.feilner-it.net/files/MFpub.asc Xing: http://www.xing.com/profile/Markus_Feilner LinkedIn: https://www.linkedin.com/in/markusfeilner @mfeilner: Mastodon, Matrix, Jabber, ...
Stakanov wrote:
I find the new behavior a bit confusing. Before I had the ethernet cabled connection set up without IP to be used via the bridge (and that bridge would then serve and is necessary to me, as interface for my KVM virtual machines.
Now however I have the loopback interface that is always there and always connected....to 127.0.0.1 but...my cabled ethernet connection is not shown anymore in the list, only lo and br0.
Showing only the bridge and not the bridged device does make some sense.
And to make it more curious when I hover over the symbol of the Network manager in the tray, I DO(!) see three cabled ethernet lo, cabled ethernet enp7s0 and br0 interfaces. But not in the list of interfaces when I open it, there just lo and br0
Wild guess - you have actual management options for 'lo' and 'br0', but none for 'enp7s0' - that might be why it isn't shown? -- Per Jessen, Zürich (15.3°C) Member, openSUSE Heroes (2016 - present) We're hiring - https://en.opensuse.org/openSUSE:Heroes
participants (7)
-
Andrei Borzenkov -
Carlos E. R. -
joe a -
kschneider bout-tyme.net -
Markus Feilner -
Per Jessen -
Stakanov