«your servers “lan” interface has no IPv4 address» ok, so how can that be fixed?

«Is this another machine in your network already, or is that a typo?» Probably a typo, I just copied it mindlessly :/. Now I have this:

dhcp-range=192.168.0.25,192.168.0.50,24h
dhcp-option=option:router,192.168.0.1
dhcp-option=option:ntp-server,192.168.0.1
dhcp-option=option:dns-server,192.168.0.1
dhcp-option=option:netmask,255.255.255.0

thanks for your response!

1: the cable was indeed bad (it was brand new, so I wasn’t suspecting it), but something else is still wrong

2: sorry for just pasting, I’m not really sure how to interpret it client:

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 global lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: enp0s25: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether f0:de:f1:5d:57:0c brd ff:ff:ff:ff:ff:ff
    inet6 fe80::29d:f28a:75a7:b5ab/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
3: wlp3s0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
    link/ether e2:a8:25:b3:ef:1a brd ff:ff:ff:ff:ff:ff permaddr 00:24:d7:a6:ce:e4
4: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default 
    link/ether 02:42:0f:11:f5:37 brd ff:ff:ff:ff:ff:ff
    inet 172.17.0.1/16 brd 172.17.255.255 scope global docker0
       valid_lft forever preferred_lft forever

server:

1: lo: <LOOPBACK,MULTICAST,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 global lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
3: enp0s25: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 6e:10:39:1a:0b:03 brd ff:ff:ff:ff:ff:ff
    inet6 fe80::2721:8559:a60d:2e65/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
4: enp0s29u1u5: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN group default qlen 1000
    link/ether 02:48:11:4d:31:03 brd ff:ff:ff:ff:ff:ff
    inet 192.168.167.220/24 brd 192.168.167.255 scope global dynamic noprefixroute enp0s29u1u5
       valid_lft 3540sec preferred_lft 3540sec
    inet6 fe80::6c7f:73bd:fb6c:bacd/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever

2a: I’m using network manager, it has worked so far. When I try to connect to the wired network manually (normally it does it automatically), nmtui says Could not activate connection: Activation failed: IP configuration could not be reserved (no available address, timeout, etc.). Dnsmasq is running, but I don’t know hot to check where is’t listening (I tried looking it up, but didn’t find anything).

2b: http://ix.io/4z3X/text

3: it only shows the dummy docker thing; when I connect to the wi-fi hotspot in my phone, it does appear and I can ping it

4: I’m not sure, the nftables config is pasted in the original post

I connect a different device with a cable and I expect it would get an internet connection or at least a local connection. But, well, nothing happens. There are no messages in dmesg or /var/log/messages on both machines either.