Linux Networking Commands

Network Related Commands, Tools & Files

Configuration commands and tools Note: See Man pages for use; you may need to use the locate command to find some of these.

netconfig -set up initial networking
hostname -your fully qualified host name
ipchains -firewall and masqarading
iptables -firewall and masqarading
mount -check what remote file systems are mounted
chkconfig -this controls which scripts run at bootup
netconfig -set up networking
netconf -configure networking
netstat -lots of info re routing, etc.
tcpdump -dumps all tcp traffic to screen
ifconfig -displays or manipulates the network interfaces
ifup -use to activate a singe interface, as opposed to using /etc/ini.d/network start
ifdown -use to stop a singe active interface, as opposed to using /etc/ini.d/network stop
nslookup -get information from name servers (replaced by host or dig)
host -DNS lookup utility
dig -send domain name query packets to name servers
pump -configure net interface using DHCP protocol
whois -retrieves info on domains by name, also see whois.arin.net for lookup via IP

Network Related Files (some of many)

To view or edit network card configuration files look in /etc/sysconfig/network-scripts/
If you have loaded your network cards as modules you can view or edit the driver, IRQ and I/O in /etc/conf.modules

Other network related files:
/etc/hosts
/etc/hosts.allow and hosts.deny
/etc/exports
/etc/named.conf and the directory it references if running DNS server
/etc/inetd.conf
/etc/nsswitch.conf
/etc/resolv.conf
/etc/sysconfig/network
/etc/sysconfig/network-scripts/ and inclosed files

Ping or Traceroute codes
Result Codes seen in traceroute and possibly ping output:

        !   Success

        *   Time out

        N   Network Unreachable

        H   Host Unreachable

        P   Protocol Unreachable

        A   Admin Denied (Access List)

        Q   Source Quench Received (Congestion)

        ?   Unknown (any other ICMP message)

original document created by Pete Nesbitt, September 2000