Networking in Linux
fing install: fing.com/products/development-toolkit
used to scan network for ip addresses
view routing table
$ sudo route -n
ug: Network is up & gateway is up
u: Network is up
Network config
create an interface and bring it up
$ ifconfig eth0 192.168.2.1 netmask 255.255.255.0 up
bring an interface up or down
$ ifup eth0
$ ifdown eth0
IP command
- Manipulate network stack of system
show info for all interfaces
$ iplink show
show statistics for an interface
$ ip -s link show eth0
show ip addresses allocated to interfaces
$ ip address show
Bring interfaces up and down
$ ip link set eth0 up/down
Add ip address to an interface
$ ip address add 192.168.1.1/24 dev eth0
Route
(route commands)
add new route
$sudo route add -net 192.168.2.1/23 gw 10.11.12.3
remove a route
sudo route del -net 192.168.2.1/23
(ip commands)
add a route
$ ip route add 192.168.2.1/23 via 10.11.12.3
delete a route
$ ip route delete 192.168.2.1/23
DHCLIENT
- dhclient starts on boot >
- gets a list of network interfaces from dhclient.conf file
- tries to configure each interface using dhcp
- Keeps track of leases across system reboots
- dhclient.conf is read
- dhclient.leases is read to see what leases are assigned
Obtain a fresh ip
$ sudo dhclient
Network manager (Daemon)
- configures networks automatically
- applet software in gui
command line tools to interact with network manager
nmtool
- reports Network managers state and it’s devices
$ nm-tool
$ nmcli
- control and modify network manager
arp
$ arp
- view arp cache
$ ip neighbor show
- view arp cache