lwc:networking:start [wiki]

This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong.
==== ubuntu and variants ====
  * give priority to Wi-Fi over Ethernet for Internet connections:  ''Wired Connection'' -> ''IPv4 Settings'' -> ''Routes'' -> ''Use this connection only for resources on its network.'' ([[https://askubuntu.com/questions/424474/how-can-i-give-internet-priority-to-wifi-instead-of-ethernet|source]])
  * check speed of NIC: ''cat /sys/class/net/<interface>/speed''
  * check bandwidth of what is being sent in realtime with ''nethogs''. Add the ''-C'' option to ''nethogs'' to see both UDP and TCP (shows only TCP by default)

===== Netplan =====
''Netplan'' is a front end for ''systemd-networkd''
  * restarting netplan: ''systemd restart systemd-networkd.service''
  * try and optionally use a new netplan config:  ''netplan try''
  * configuration are YAML files that go inside ''/etc/netplan''
  * in the config file choose ''Network Manager'' as renderer for GUI, or ''networkd'' to configure inside the YAML file
  * [[https://netplan.readthedocs.io/en/stable/examples/|example configurations]]
  * [[https://netplan.readthedocs.io/en/stable/netplan-yaml/|netplan official documentation]]
==== Example Netplan yaml file to create a bridge ====
<code>
network:
    version: 2
    renderer: networkd
    ethernets:
      enp1s0:
        dhcp4: no
      eno1:
        dhcp4: no
      enxf8e43b6c9b8c:
        dhcp4: true    
    bridges:
      br2:
        dhcp4: no
        addresses: 
          - 10.42.0.1/24
        interfaces:
          - enp1s0
          - eno1
</code>
With this configuration you can treat br2 as if it were a real physical interface (run a DHCP server on it, etc.)
===== Sharing Internet with an interface =====
  * configure the userspace to allow ipv4 forwarding:
    * temporary: ''sudo echo 1 | sudo tee /proc/sys/net/ipv4/ip_forward''
    * persistant: change setting in ''/etc/sysctl.conf''
  * assuming ''enxf8e43b6c9b8c'' connects to the internet and ''br2'' is the interface you wish to share internet with
<code>
#iptables -t nat -A POSTROUTING -o enxf8e43b6c9b8c -j MASQUERADE
#iptables -A FORWARD -i enxf8e43b6c9b8c -o br2 -m state --state RELATED,ESTABLISHED -j ACCEPT
#iptables -A FORWARD -i br2 -o enxf8e43b6c9b8c -j ACCEPT
</code>
  * install ''iptables-persistent'' to retain iptables rules on reboot.
=== Configure isc-dhcp-server ===
  * inside ''/etc/default/isc-dhcp-server'' set the interface.
    * Assuming interface for dhcp server will be br2: ''INTERFACESv4="br2"''
  * configuration goes inside ''/etc/dhcp/dhcpd.conf''
    * Assuming interface for DHCP server is at 10.42.0.1, example config:
<code>
ddns-update-style none;
authoritative;
default-lease-time 600;
max-lease-time 7200;
subnet 10.42.0.0 netmask 255.255.255.0 {
  range 10.42.0.50 10.42.0.254;
  option routers 10.42.0.1;
  option domain-name-servers 8.8.8.8, 8.8.4.4;
}
</code>