Linux Networking Commands

Linux Networking Commands Copyright, 2002 © NTM Consulting Inc. TCP/IP Lecture Series Professor Tom Mavroidis

Commands Reviewed Ifconfig dmesg netstat ping route traceroute nslookup arp dig

ifconfig eth0 ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

When would you use ifconfig? ,[object Object],[object Object],[object Object]

What should you do if the interface isn’t found? ,[object Object],[object Object],[object Object]

See if the device has been found - use dmesg ,[object Object],[object Object],TIP pipe the dmesg to the less command or the reply will scroll off the screen dmesg | less

Before you have a useable interface ,[object Object],[object Object],[object Object]

Does the localhost respond? ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Confirm you have set up the interface correctly. ,[object Object],eth0 Link encap:Ethernet HWaddr 00:04:AC:16:54:4C inet addr: 192.168.2.1 Bcast:192.168.2.255 Mask:255.255.255.0 inet6 addr: fe80::204:acff:fe16:544c/10 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:116242 errors:0 dropped:0 overruns:0 frame:0 TX packets:123380 errors:0 dropped:0 overruns:0 carrier:0 collisions:9052 RX bytes:39103579 (37.2 Mb) TX bytes:106270739 (101.3 Mb)

route ,[object Object],[object Object],[object Object],[object Object]

route -n ,[object Object],[object Object],[root@localhost root]# route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 192.168.2.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1 127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo 0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 eth1

route -Cn (display cache table) ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

traceroute ,[object Object],Note Traceroute has lost some of its effectiveness since most ISP’s disallow it from running on their networks

arp ,[object Object],[object Object]

arp table ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

/etc/hosts ,[object Object],[root@localhost root]# less /etc/hosts # Do not remove the following line, or various programs # that require network functionality will fail. 127.0.0.1 localhost.localdomain localhost 192.168.1.1 gatewayout.tcp-ip.ca 192.168.2.75 basement.tcp-ip.ca 192.168.1.101 just_a_node.tcp-ip.ca

arp -a will then resolve ,[object Object],[object Object],[object Object],[object Object],[object Object]

netstat -nr ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

dig - supercharged nslookup ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

dig - better than nslookup ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

References ,[object Object],[object Object]

Linux Networking Commands

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Viewers also liked

Viewers also liked (19)

Similar to Linux Networking Commands

Similar to Linux Networking Commands (20)

More from tmavroidis

More from tmavroidis (18)

Recently uploaded

Recently uploaded (20)

Linux Networking Commands