Various Network Commands with all it's Suffix and Eample

Commands

1. PING:  

Ping is a computer network administration software utility used to test the reach-ability of a host on an Internet Protocol (IP) network. It measures the round-trip time for messages sent from the originating host to a destination computer that are echoed back to the source. The name comes from active sonar terminology that sends a pulse of sound and listens for the echo to detect objects under water, although it is sometimes interpreted as a acronym to packet Internet groper.

Ping operates by sending Internet Control Message Protocol (ICMP) Echo Request packets to the target host and waiting for an ICMP Echo Reply. The program reports errors, packet loss, and a statistical summary of the results, typically including the minimum, maximum, the mean round-trip times, and standard deviation of the mean.

The command-line options of the ping utility and its output vary between the numerous implementations. Options may include the size of the payload, count of tests, limits for the number of network hops (TTL) that probes traverse, and interval between the requests. Many systems provide a companion utility ping6, for testing on Internet Protocol version 6 (IPv6) networks.

SYNTAX: ping www.google.com

2. TRACERT:

 Traceroute is a computer network diagnostic tool for displaying the route (path) and measuring transit delays of packets across an Internet Protocol (IP) network. The history of the route is recorded as the round-trip times of the packets received from each successive host (remote node) in the route (path); the sum of the mean times in each hop is a measure of the total time spent to establish the connection. Traceroute proceeds unless all (three) sent packets are lost more than twice, then the connection is lost and the route cannot be evaluated. Ping, on the other hand, only computes the final round-trip times from the destination point.

The command trace route is available on many modern operating systems. On Apple macOS, it is available by opening the menu Network Utilities and selecting Trace route, as well as from the command line interface in a terminal. On other Unix systems, such as FreeBSD or Linux, it is also available as a command line tool. On Microsoft Windows, it is named tracert. Windows NT-based operating systems also provide PathPing, with similar functionality. For Internet Protocol Version 6 (IPv6) the tool sometimes has the name traceroute6 or tracert6.

SYNTAX: tracert www.google.com

Most implementations include at least options to specify the number of queries to send per hop, time to wait for a response, the hop limit and port to use. Invoking traceroute with no specified options displays the list of available options, while man traceroute presents more details, including the displayed error flags. Simple example on Linux:

$ Traceroute -w 3 -q 1 -m 16 example.com


In the example above, selected options are to wait for three seconds (instead of five), send out only one query to each hop (instead of three), limit the maximum number of hops to 16 before giving up (instead of 30), with example.com as the final host.

This can help identify incorrect routing table definitions or firewalls that may be blocking ICMP traffic, or high port UDP in UNIX ping, to a site. Note that a firewall may permit ICMP packets but not permit packets of other protocols.

3. HOSTNAME:

In computer networking, a hostname (archaically node name) is a label that is assigned to a device connected to a computer network and that is used to identify the device in various forms of electronic communication, such as the World Wide Web. Hostnames may be simple names consisting of a single word or phrase, or they may be structured.

On the Internet, hostnames may have appended the name of a Domain Name System (DNS) domain, separated from the host-specific label by a period ("dot"). In the latter form, a hostname is also called a domain name. If the domain name is completely specified, including a top-level domain of the Internet, then the hostname is said to be a fully qualified domain name (FQDN). Hostnames that include DNS domains are often stored in the Domain Name System together with the IP addresses of the host they represent for the purpose of mapping the hostname to an address, or the reverse process.


SYNTAX: hostname

On the Internet, a hostname is a domain name assigned to a host computer. This is usually a combination of the host's local name with its parent domain's name. For example, en.wikipedia.org consists of a local hostname (en) and the domain name wikipedia.org. This kind of hostname is translated into an IP address via the local hosts file, or the Domain Name System (DNS) resolver. It is possible for a single host computer to have several hostnames; but generally the operating system of the host prefers to have one hostname that the host uses for itself.
Any domain name can also be a hostname, as long as the restrictions mentioned below are followed. So, for example, both en.wikipedia.org and wikipedia.org are hostnames because they both have IP addresses assigned to them. The domain name pmtpa.wikimedia.org is not a hostname since it does not have an IP address (as of now), but rr.pmtpa.wikimedia.org is a hostname. A hostname may be a domain name, if it is properly organized into the domain name system. A domain name may be a hostname if it has been assigned to an Internet host and associated with the host's IP address.

4. NETSTAT:

In computing, netstat (network statistics) is a command-line network utility tool that displays network connections for the Transmission Control Protocol (both incoming and outgoing), routing tables, and a number of network interface (network interface controller or software-defined network interface) and network protocol statistics. It is available on Unix-like operating systems including macOS, Linux, Solaris, and BSD, and is available on Windows NT-based operating systems including Windows XP, Windows Vista, Windows 7, Windows 8 and Windows 10.
It is used for finding problems in the network and to determine the amount of traffic on the network as a performance measurement.

On Linux, netstat (part of "net-tools") is superseded by ss (part of iproute2), which is recommended instead.

SYNTAX:netstat–an

Netstat provides statistics for the following:

·         Proto - The name of the protocol (TCP or UDP).

·         Local Address - The IP address of the local computer and the port number being used. The name of the local computer that corresponds to the IP address and the name of the port is shown unless the -n parameter is specified. An asterisk (*) is shown for the host if the server is listening on all interfaces. If the port is not yet established, the port number is shown as an asterisk.

·         Foreign Address - The IP address and port number of the remote computer to which the socket is connected. The names that corresponds to the IP address and the port are shown unless the -n parameter is specified. If the port is not yet established, the port number is shown as an asterisk (*).

·         State - Indicates the state of a TCP connection. The possible states are as follows: CLOSE_WAIT, CLOSED, ESTABLISHED, FIN_WAIT_1, FIN_WAIT_2, LAST_ACK, LISTEN, SYN_RECEIVED, SYN_SEND, and TIME_WAIT. For more information about the states of a TCP connection, see RFC 793

5. ARP: Address Resolution Protocol

The Address Resolution Protocol (ARP) s a telecommunication protocol used for resolution of Internet layer addresses into link layer addresses, a critical function in computer networks. ARP was defined by RFC 826 in 1982, is Internet Standard STD 37, and is also the name of the program for manipulating these addresses in most operating systems.

ARP is used for mapping a network address (e.g. an IPv4 address) to a physical address like an Ethernet address (also named a MAC address). ARP has been implemented with many combinations of network and data link layer technologies, like IPv4, Chaosnet, DECnet and Xerox PARC Universal Packet (PUP) using IEEE 802 standards, FDDI, X.25, Frame Relay and Asynchronous Transfer Mode (ATM). IPv4 over IEEE 802.3 and IEEE 802.11 is the most common usage.

In Internet Protocol Version 6 (IPv6) networks, the functionality of ARP is provided by the Neighbor Discovery Protocol (NDP)

SYNTAX: arp –a