netstat

Question 1

netstat

Answer 1

Netstat prints information about the Linux networking subsystem. The type of information printed is controlled by the first argument.

Question 2

netstat

• r, –route, Display routing table.
• i, –interfaces, Display interface table.
• g, –groups, Display multicast group memberships.
• s, –statistics, Display networking statistics (like SNMP).
• M, –masquerade, Display masqueraded connections.

Answer 2

netstat [OPTIONS]

• v, –verbose.
• W, –wide, Do not truncate IP addresses.
• n, –numeric, Show numerical addresses.

–numeric-hosts

–numeric-ports

–numeric-users, Numeric user IDs.

Question 3

netstat [OPTIONS]

• A, –protcol=family, Specifies address family: inet, inet6, unix, ipx, ax25, netrom, econet, ddp, and bluetooth.
• c, –continuous
• e, –extend
• o, –timers, Include info related to networking timers.
• p, –program, Show the PID and name of program each socket blelongs to.

Answer 3

• l, –listening, Show only listening
• a, –all, Show both listening and not
• F, Print routing info from the FIB
• C, Print routing info from the route cache.

Question 4

netstat [OUTPUT]

Active Internet connections(TCP, UDP, UDPLite, raw)

Proto, protocol used by socked.

Recv-Q, Count of bytes not copied by the user program connected to socket.

Send-Q, Count of bytes not acknowledged by remote host.

Local Address, Address and port number of local end of the socket.

Foreign Address, Address and port number of the remote end of the socket.

Answer 4

State, the state of socket.

User, the username or user id of socket owner.

PID/Program name

Timer

Active Unix domain Sockets

Proto, Protocol used by socket.

RefCnt, The reference count.