# Cheatsheet & Examples: ping

The `ping` command is a network utility used to test the reachability of a host on an Internet Protocol (IP) network. It works by sending Internet Control Message Protocol (ICMP) echo request packets to the target host and listening for echo response packets.

## Basic Ping to a Host

Example Usage:
`ping google.com`

What it does:
Sends ICMP echo request packets to the host `google.com` and displays the round-trip time for each packet received. It will continue to ping the host indefinitely unless interrupted.

Command-line Arguments Explained:

-  `google.com`: This is the hostname or IP address of the target host you want to test.

## Ping with a Specific Count

Example Usage:
`ping -c 4 google.com`

What it does:
Sends a specified number of ICMP echo request packets to the host. After receiving the specified number of responses or a timeout, it displays statistics.

Command-line Arguments Explained:

- `-c 4`: This option specifies the number of echo requests to send. In this example, it sends 4 packets.
- `google.com`: The target host.

## Ping with a Timeout

Example Usage:
`ping -W 2 -c 3 google.com`

What it does:
Sends a specified number of packets, but with a timeout setting, meaning the ping will terminate if no response is received within the specified number of seconds.

Command-line Arguments Explained:

- `-W 2`: Specifies the timeout in seconds to wait for a response.
- `-c 3`: Specifies the number of packets to send, in this example, 3.
- `google.com`: The target host.

## Ping with a Packet Size Adjustment

Example Usage:
`ping -s 1000 google.com`

What it does:
Sends ICMP echo requests with a specified packet size. This can be useful for testing network MTU (Maximum Transmission Unit) and for general network performance testing.

Command-line Arguments Explained:

- `-s 1000`:  Specifies the size of the ICMP payload in bytes. The default is typically 56 bytes. This value, plus the ICMP header, results in a larger packet size being sent.
- `google.com`: The target host.

## Ping with a Time to Live (TTL) Adjustment

Example Usage:
`ping -t 64 google.com`

What it does:
Sends ICMP echo requests with a specific time to live (TTL) value. TTL defines how many hops a packet can make before being discarded.

Command-line Arguments Explained:

- `-t 64`: Specifies the TTL value for the packets.
- `google.com`: The target host. Note that this option is not available on all ping implementations. Some systems might have an equivalent with different syntax.

## Ping Using Numeric IP Address

Example Usage:
`ping 8.8.8.8`

What it does:
Sends ICMP echo request packets to the IP address 8.8.8.8, which is Google's public DNS server.

Command-line Arguments Explained:

- `8.8.8.8`: The numeric IP address of the target host.