Networking
Basic Commands
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ip a |
Display network inerfaces and details |
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ip addr |
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ifconfig |
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hostnamectl set-hostname <hostname> |
set hostname |
NetworkManager
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systemctl status NetworkManager |
NetworkManager status |
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ps -ef | grep NetworkManager |
verify the process is running |
Network Configuration Methods
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nmcli |
network manager cli (non gui) can be used in scripts |
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nmtui |
text user interface |
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nm-connection-editor |
full gui (via desktop/console) |
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GNOME Settings |
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Creating a New Connection Profile
nmcli con add type ethernet ifname enp0s3 con-name myprofile1
Use nmcli to set a static ip address
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nmcli connection |
connected interface UUIDs |
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nmcli device |
connected interface status |
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nmcli connection modify eth0 ipv4.addresses 192.168.50.X/24 |
set static ip address & subnet mask |
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nmcli connection modify eth0 ipp4.gateway 192.168.50.1 |
set gateway |
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nmcli connection modify eth0 ipv4.method manual |
configure eth0 to use static IP |
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nmcli connection modify eth0 ipv4.dns 8.8.8.8 |
set dns to google.com |
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nmcli connection down eth0 && nmcli connection up eth0 |
restart nmcli connection |
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ip address show eth0 |
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Use nmcli to configure a secondary static ip address
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nmcli device status |
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nmcli connection show --active |
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ifconfig |
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nmcli connection modify eth0 +ipv4.addresses 192.168.50.X/24 |
set secondary static ip address & subnet mask |
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nmcli connection reload |
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systemctl reboot |
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ip address show |
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nmtui (as root), nm-connection-editor or GNOME settings can also be used to activate a connection or change hostname
Network Files and Basic Commands
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/etc/sysconfig/network-scripts |
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/etc/hosts |
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/etc/hostname |
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/etc/resolv.conf |
DNS |
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/etc/nsswitch.conf |
Set to use Files or DNS first (per command/request) |
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ping |
verify network connectivity to a host |
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ifconfig |
Display network interfaces and IP addresses |
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ip addr |
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ip a |
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ifup |
brings up a specific network interface |
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ifdown |
takes down a specific network interface |
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traceroute |
track and display path (router/hops) that packets take to reach a destination host |
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tcpdump -i eth0 |
capture and monitor live network traffic flowing through eth0 |
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nslookup |
queries DNS servers to find ip adddress of a domain or vice versa |
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dig |
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ethtool eth0 |
display and modify physical hardware settings of eth0 such as link speed & duplex |