Server unreachable on local network

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For a few days my server (old lenovo tank) has suddenly become almost unreachable from a single pc in the house (asus laptop used as living room media center)… By almost unreachable i mean that several minutes are needed to log in, and every app also takes several minutes to not load, chrome consoles is filled with “unreachable resource” and “timeout” errors. The problem only occurs on the local network, on this particular pc (any other plugged on the same cable works fine) and through ethernet but wifi works like a charm.

I tried changing its ip on the router’s dhcp lease, i looked in the fail2ban jails, tried regenerating various ynh configurations, nothing changed… Any idea of what could’ve gone wrong or some logs that i could paste here ?


Depuis quelques jours mon serveur (vieux bourrin lenovo) est quasi injoignable depuis un des pc de la maison (laptop asus dans la salon) : il faut plusieurs minutes pour se logger et n’importe quelle app met autant de temps à ne pas charger et à remplir la console de chrome d’erreur timeout et resource unreachable. Ça n’arrive que depuis le réseau local, que en ethernet, que sur ce pc (un autre branché au même cable fonctionne) mais le wifi fonctionne.

J’ai essayé de changer l’ip fixe dudit pc, j’ai checké fail2ban, regénéré des confs ynh dans le doute, rien n’y fait… Z’avez une idée de ce qui coincerait ou de logs pertinents à donner ?

Hi Aristid. I’m not sure to understand your network topology. Is your Lenovo connected through ethernet and wifi or is it the Asus, or both?

Since it might be a networking problem, the output of ip a, ip route and ip -6 route from both PCs would help.


Salut Aristid. Je ne suis pas sûr de bien comprendre la topologie de ton réseau. est-ce le Lenovo qui est connecté par ethernet et wifi ou l’Asus, ou les deux ?

Vu qu’il se pourrat que ça soit un problème de réseau, la sortie des commandes ip a, ip route et ip -6 route sur les deux PC serait utile.

Let me be a bit clearer… Installation is as such :

  • Lenovo server in a closet with router (providing wired and wifi connection) and a switch, all wired in ethernet
  • In the living room an ethernet cable comes out the wall and is plugged to a laptop (our culprit here)

Behaviour is like :

  • When the living room laptop is wired, connection to yunohost is sketchy at best, impossible most of the time.
  • When this particular laptop is on wifi everything works fine.
  • When another pc is plugged to the same ethernet cable, everything works fine…

So i’m guessing it is either an issue about the living room pc ethernet card or configuration, or it might be a router issue, but there is no visible change on either side…


Pour être plus clair, voici l’install :

  • vieux lenovo dans le placard avec routeur (ethernet + wifi) et un switch pour avoir plus de ports
  • dans le salon un rj45 qui sort du mur et qui vient dans le laptop incriminé ici

Voilà ce qui se passe :

  • le laptop du salon en ethernet : l’accès au serveur est tout foireux, la plupart du temps impossible
  • le laptop du salon en wifi : tout fonctionne easy
  • un autre pc connecté sur l’ethernet du salon : tout fonctionne easy

Ça me donne l’impression d’être un problème au niveau du pc du salon (config ou carte réseau), ou du routeur, mais rien n’a changé nulle part…

server side :

ip a

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: enp1s0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN group default qlen 1000
    link/ether 50:3e:aa:0b:4c:f7 brd ff:ff:ff:ff:ff:ff
3: enp0s25: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 1c:6f:65:03:ac:f8 brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.5/24 brd 192.168.1.255 scope global dynamic noprefixroute enp0s25
       valid_lft 70697sec preferred_lft 70697sec
    inet6 fe80::c349:4fdd:a9b8:4dda/64 scope link
       valid_lft forever preferred_lft forever

ip route

default via 192.168.1.1 dev enp0s25 src 192.168.1.5 metric 203
192.168.1.0/24 dev enp0s25 proto dhcp scope link src 192.168.1.5 metric 203

ip -6 route

::1 dev lo proto kernel metric 256 pref medium
fe80::/64 dev enp0s25 proto kernel metric 256 pref medium

It’s a problem with the ethernet card of your laptop.
If you try to copy files from other pcs in your network, is it OK?
Try to update (or downgrade) the driver of your laptop ethernet card

It’s likely a hardware or network configuration issue on the Asus laptop. A router problem is very unlikely, unless you have specific settings based on hardware addresses.

Nework configuration issues should be visible in the routing table of the laptop.

I just noticed that the webdav connection to nextcloud server works (nextcloud is on the same server that is really hard to connect to).

Anyway here are the CLI outputs on the living room laptop, while wired :

ip a


1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: enp3s0f1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 70:8b:cd:0a:e8:6b brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.111/24 brd 192.168.1.255 scope global dynamic noprefixroute enp3s0f1
       valid_lft 86396sec preferred_lft 86396sec
    inet6 fe80::3dac:e5a1:bd81:ce56/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
3: wlp2s0: <BROADCAST,MULTICAST> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
    link/ether 48:45:20:c4:db:6e brd ff:ff:ff:ff:ff:ff

ip route

default via 192.168.1.1 dev enp3s0f1 proto dhcp metric 100 
169.254.0.0/16 dev enp3s0f1 scope link metric 1000 
192.168.1.0/24 dev enp3s0f1 proto kernel scope link src 192.168.1.111 metric 100

ip -6 route

 ::1 dev lo proto kernel metric 256 pref medium
fe80::/64 dev enp3s0f1 proto kernel metric 100 pref medium

Ok i just reinstalled a fresh, updated ubuntu 22.04 on the living room pc (which should have take care of any ethernet card driver issue) and server is still unreachable… How could it be a hardware problem if everything else works netword wise ?

I just put this particular PC on a fixed IP…

Everything you posted looks fine. Your tests point to a problem on this PC, but reinstalling the OS didn’t solve it, so I’m a bit confused…

Yep, same here…

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