System information

Manual:Troubleshooting tools

netstat – print network connections, including port connections, routing tables, interface statistics, masquerade

connections, and more. (netstat – r, netstat - a)

ip – show/manipulate routing, devices, policy routing and tunnels on linux-machine.

For example, check IP address on interface using ip command:

$ip addr show

You can add static route using ip following command:

ip route add {NETWORK address} via {next hop address} dev {DEVICE}, for example:

$ip route add 192.168.55.0/24 via 192.168.1.254 dev eth1

mentioned tools are only small part of networking tools that is available on Linux. Remember if you want full details

on the tools and commands options use man command. For example, if you want to know all options on ifconfig

write command man ifconfig in terminal.

Check network connectivity

Using the ping command

Ping is one of the most commonly used and known commands. Administration utility used to test whether a

particular host is reachable across an Internet Protocol (IP) network and to measure the round-trip time for packets

sent from the local host to a destination host, including the local host's own interfaces.

Ping uses Internet Control Message Protocol (ICMP) protocol for echo response and echo request. Ping sends ICMP

echo request packets to the target host and waits for an ICMP response. Ping output displays the minimum, average

and maximum times used for a ping packet to find a specified system and return.

From PC:

Windows:

C:\>ping 10.255.255.4

Pinging 10.255.255.4 with 32 bytes of data:

Reply from 10.255.255.4: bytes=32 time=1ms TTL=61

Reply from 10.255.255.4: bytes=32 time<1ms TTL=61

Ping statistics for 10.255.255.4:

Packets: Sent = 4, Received = 4, Lost = 0 (0%

Approximate round trip times in milli-seconds:

Minimum = 0ms, Maximum = 1ms, Average = 0ms

Unix-like:

andris@andris-desktop:/$ ping 10.255.255.6

PING 10.255.255.6 (10.255.255.6) 56(84) bytes of data.

64 bytes from 10.255.255.6: icmp_seq=1 ttl=61 time=1.23 ms

64 bytes from 10.255.255.6: icmp_seq=2 ttl=61 time=0.904 ms

64 bytes from 10.255.255.6: icmp_seq=3 ttl=61 time=0.780 ms

64 bytes from 10.255.255.6: icmp_seq=4 ttl=61 time=0.879 ms

--- 10.255.255.6 ping statistics ---