Friday, August 21, 2009

Useful Wireless Networking Connection Commands - Ubuntu/Debian Linux

Here I am trying to explain some useful Linux commands for wireless networking

iwlist scan
- shows wireless networks that are available in the area with basic encryption information
lshw -C network - Shows Details of Interface card and drivers of each networking device

lspci -nn - Shows PCI vendor and device codes as both numbers and names of hardware connected to the pci bus
lsusb - Shows USB connected hardware
lshw -C usb - Additional info on USB related hardware (good for USB dongles)

route -n - Lists kernel IP routing table — Good for troubleshooting problems with the gateway

sudo route add default gw - Example of how to set the default gateway to

sudo route del default gw - Example of how to delete the default gateway setting

sudo modprobe ***** - Loads the kernel module **** . (Example usage - sudo modprobe ndiswrapper, sudo modprobe r818x, sudo modprobe ath_pci)

sudo modprobe -r **** - Unloades the kernel module ****. (Example usage - sudo modprobe -r ndiswrapper)

ifconfig - lists IP address

sudo ifup/ifdown - Brings up/down the interface and clears the routing table for the specified interface

sudo ifconfig up/down - Brings up/down the interface for the specified interface

sudo dhclient - Request IP address from DNS server for specified interface

sudo dhclient -r - Release IP address associated with specified interface

sudo iptables -L - Lists firewall rules

sudo iptables -F - Flush all firewall rules

dmesg | more - Lists boot log — good for troubleshooting problems with modules/drivers not being loaded

uname -r - Displays kernel version

/etc/udev/rules.d/70-persistent-net.rules - File which assigns logical names (eth0, wlan0, etc) to MAC addresses

cat /etc/resolv.conf - Lists DNS servers associated with network connections (Network Manager)

/etc/dhcp3/dhclient.conf - File which sets or modifies dns (domain name servers) settings