condividere connessione Tethering USB

[nik57]

al momento sto usando, per navigare, lo smartfone connesso via usb al pc1; vorrei condividere la connessione con altro pc casalingo (pc2) ma non ci riesco;
su entrambi i pc è installato Mate 18.04-64 bit

- i due pc sono collegati via cavo ad un Tp-link Arcer D50 che usavo per navigare fino al mese scorso, e che ho lasciato per scambiare file (via ssh) e per altri motivi tra i due pc;
- i due pc pingano
- il pc2 ha due schede di rete, il pc1 una

ho provato ad impostare nel pc1 (a cui è collegato lo smartfone) in Impostazioni IPV4 "Condiviso con altri computer" ma il pc2 continua ad essere offline...
non ho idea di come impostare le voci (credo in "Impostazioni IPv4) del pc2..

alcuni dati
pc1

ubuntu@ubuntu:~$ ifconfig -a
enp0s18u1u1u2: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.42.37  netmask 255.255.255.0  broadcast 192.168.42.255
        inet6 fe80::5b78:5ef5:5360:7b84  prefixlen 64  scopeid 0x20<link>
        ether 36:d1:12:6f:a1:fc  txqueuelen 1000  (Ethernet)
        RX packets 44690  bytes 45880385 (45.8 MB)
        RX errors 99  dropped 0  overruns 0  frame 99
        TX packets 30746  bytes 5785365 (5.7 MB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

enp1s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.1.100  netmask 255.255.255.0  broadcast 192.168.1.255
        inet6 fe80::a657:9188:782a:52b6  prefixlen 64  scopeid 0x20<link>
        ether 48:0f:cf:bc:f6:91  txqueuelen 1000  (Ethernet)
        RX packets 146609  bytes 11746511 (11.7 MB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 168168  bytes 13686307 (13.6 MB)
        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
        loop  txqueuelen 1000  (Loopback locale)
        RX packets 7394  bytes 541003 (541.0 KB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 7394  bytes 541003 (541.0 KB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

pc2

nik@nik:~$ ifconfig -a
enp1s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.1.103  netmask 255.255.255.0  broadcast 192.168.1.255
        inet6 fe80::9c6c:92a5:ca58:fe56  prefixlen 64  scopeid 0x20<link>
        ether 00:08:9b:bc:a1:b6  txqueuelen 1000  (Ethernet)
        RX packets 27407  bytes 3294740 (3.2 MB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 24394  bytes 2020452 (2.0 MB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
        device interrupt 16  

enp2s0: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
        ether 00:08:9b:bc:a1:b7  txqueuelen 1000  (Ethernet)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
        device interrupt 17  

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        loop  txqueuelen 1000  (Loopback locale)
        RX packets 1463  bytes 103156 (103.1 KB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 146