Linux Networking

Monitoring

with netstat : netstat -a | grep LISTEN

Network Configuration

In Debian the network settings are specified in /etc/network/interfaces In Redhat and Mandrake, this is found in /etc/sysconfig/network A network configuration file looks like this: NETWORKING=yes HOSTNAME=p15145407.pureserver.info GATEWAY=192.158.254.1 # Optional - only used if pc isn’t connected directly to the internet

In Fedora/Redhat, on machines with a static IP address, this is set in /etc/sysconfig/network-scripts/ifcfg-eth0 e.g. … IPADDR=192.168.254.14 NETMASK=255.255.255.0 NETWORK=192.168.254.0 … The name server is specified in a separate file, usually /etc/resolv.conf

Starting a network device

ifconfig netmask up e.g. ifconfig eth0 192.168.0.1 255.255.255.0 up

Stopping a network device

ifconfig eth0 down

Setting the dafault gateway You also may need to check the gateway is setup: route add default gw

And the network interface is configured: ifconfig eth0 192.168.254.9 netmask 255.255.255.0 up

Name Servers

Name Servers are specified in /etc/resolv.conf you must restart the name daemon to take effect (e.g. kill the process then /usr/local/sbin/named -u named)

http://yolinux.com/TUTORIALS/LinuxTutorialNetworking.html

http://www.nobell.org/~gjm/linux/gateway/

Andrew McDonough is a consultant CTO and software developer, currently based between Berlin and London.

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