Networkmanager disconnects every few minutes

English Network/Internet
1

After recent zypper dup networkmanager start disconnect ethernet (internet) connection every few minutes. What is the problem could be and how to solve?

2

Please monitor the NetworkManager logging in a terminal with

sudo journalctl -fu NetworkManager

and capture the relevant output when disconnection occurs. Post here for others to advise further.

If preferred you can redirect the output to a text file, and review later…

sudo journalctl -fu NetworkManager > output.txt
3

Will do. It actually does not disconnect: it stops to receive incoming packages. Disconnect/Connect interface in NM-applet helps to restart and resume connection and incoming packages.

4

Ok, that’s a slightly different description to that mentioned in your opening post. Is this all traffic? You could try a constant ping to a well known internet address? Are you using a VPN? More info required here.

You could also check that the interface is negotiating correctly perhaps…

/usr/sbin/ethtool eth0

Unplug and re-plug a few times to ensure that it is consistent.

5

Yes, all traffic. Not using VPN. Not reproducible today after PC start. Yesterday set MTU to 8192, added

[ifupdown]
managed=true

lines to /etc/NetworkManager/NetworkManager.conf

> /usr/sbin/ethtool enp6s7
Settings for enp6s7:
        Supported ports:  TP MII ]
        Supported link modes:   10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full
        Supported pause frame use: No
        Supports auto-negotiation: Yes
        Supported FEC modes: Not reported
        Advertised link modes:  10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full
        Advertised pause frame use: No
        Advertised auto-negotiation: Yes
        Advertised FEC modes: Not reported
        Link partner advertised link modes:  10baseT/Half 10baseT/Full
                                             100baseT/Half 100baseT/Full
        Link partner advertised pause frame use: Symmetric
        Link partner advertised auto-negotiation: Yes
        Link partner advertised FEC modes: Not reported
        Speed: 100Mb/s
        Duplex: Full
        Port: MII
        PHYAD: 32
        Transceiver: internal
        Auto-negotiation: on
Cannot get wake-on-lan settings: Operation not permitted
        Current message level: 0x00000007 (7)
                               drv probe link
        Link detected: yes