ICMP protocol is mainly used for error handling and primarily used for network devices (routers). Many different types of errors exist in the network layer that time ICMP can use to debug those errors. ICMP’s full form is Internet Control Message Protocol, one network layer protocol type.

This type of IP protocol has no error-correcting or error-reporting mechanism to use the message to convey the information. If anybody sends the message, that gets stolen from the sender to the destination. If any chance there is no error, then the sender has to understand that message has reached to the destination.

If anyone is between, the sender will get the error message and must resend the message as soon as possible.

Categories of ICMP protocol Message:

These ICMP protocol messages are divided into two types.

1. Error-reporting messages: In this router will have encounter a problem when it gets processed the IP packet; the user will get a message.
2. Query messages: This is one type of message which helps the host to get information of another host. If you have a client and a server, clients want to know whether the server is going for live or not. That time it sends the ICMP message so that it can get the confirmation.

Type of Error Reporting messages:

The error-reporting messages are classified into four categories. Those are below:

1. Destination unreachable: When the packet data does not reach the destination at that time, it’s called destination unreachable. If the sender sends a message, it will not reach the destination that time the intermediate router will report.
2. Source Quench: In this, there is no flow of control mechanism that works; while sending the packet to send, do not think whether the receiver is ready to receive those packets or not. In this case, ICMP provides the feedback. Sometimes sender sends the packet in a higher rate which the router will not handle and make this situation proper source quench convey the sender to send the packet in a lower price.
3. Time exceeded: Sometimes the situation becomes like this in that many routers are between sender and receiver. The sender usually sends the packet then it gets to move to the routing loop. Time will get exceeded depending on the time-to-live value. The value will decrease as soon as the packet traverses through the router that time. When the router gets discarded, that time will get exceeded compared to the original one.
4. Parameter problem: Usually, the destination host needs to send the parameter problem message when the parameters are not set properly.
5. Redirection: As soon as packet gets sent the routing table gets updated and the user gets the redirection message.

What for ICMP to get used?

If you want to catch the reporting error, then ICMP is the best one. Whenever two devices are connected through the internet, ICMP can create the error from the receiving device to sending device so that data should not arrive as expected.

Another use of ICMP protocol is to help dragonise the tool into assets for the network’s performance. Traceroute and ping get used for the ICMP, and messages are sent for the data and successfully transmitted. It has traceroute use where the device receives its packet data and went through with the destination to display the report. This also includes the physical route which can handle the data.

This traceroute can also tell you how much time it took data to go from one device to another and how much time it required to reach to another router. This trip is usually referred to as a hop. This information is actually revealed by the traceroute that will figure out the correct device, which can cause delays.

This ping is similar to the traceroute, and it is significant. This report shows that how the data go between two points. This is always facilitates the ping where ICMP does the echo request and reply, which does the ping process.

ICMP has great use for network performance. This is also to get used for the ICMP flood and Smurf attack. The death attack ping will overwhelm the device, which can prevent the standard functionality.

What all are the ICMP message code?

ICMP’s main motto is to offer the information and the feedback related to the error. It also helps to control messages and manage queries. The first code gets a field into the ICMP block, which can get mange easily. It also conveys a great deal regarding information. You can find the few relevant values, which are described below:

1. Eco Reply: It’s mainly got used for ping.
2. Destination: In this destination is unreachable.
3. Source quench: This indicates indicate that the router is overloaded.
4. Redirect: It means it’s donate to another router.
5. Echo Request: It is similar to 0, and it gets used for ping.
6. Router solicitation: Here router will get solicited.
7. Traceroute: Here, after time will get exceed, it get used for traceroute.

How does the ICMP protocol work?

ICMP is another form of Internet Protocol (IP); the version is six and IPv6 is not associated with the TCP (Transmission Control Protocol). There is no device available to which will get connected to another ICMP message.

TCP has two devices that get communicating first engage, and it takes several steps. After this handshake gets complete, data will get transferred to the receiver from the sender. This information will get observed by using this tcpdump tool.

ICMP is a bit different, and in that connection did not get formed. The message is normally sent where TCP and UDP are included. The information got sent, and it is dedicated to the port. ICMP message gets directed to the port, and the device will receive it.

ICMP protocol in DDoS attacks:

When users distribute the DDos, attackers often overwhelm the target with the unwanted target. This target does not provide the service, and it has multiple ways where attackers uses the ICMP protocol and execute the attack. Here few ways are described below:

1. Ping of death: The attacker will send the IP packet that has to be larger than the number of bytes allowed by IP. It has an intended destination, which makes the oversize fragmented packet. When the recipient device reassembles, the size exceeds the limit, which can cause a buffer overflow. The newer device does the old attack, but legacy networking is vulnerable.
2. ICMP flood attack: This is also well-known as a ping flood attack. This attack goal is to overwhelm the target device so that it can do echo-request packets. Every echo-request packet must get processed by the target. They also will respond through an echo reply message. This gets typically sucks up with the targeted computer’s resource which is a reason for the denial service, and it has other users of the target computer.
3. Smurf attack: This attacker has to send an ICMP packet with IP address and network layer equipment. Users can also send the packets to the spoofed address. As a ping of death, the Smurf attack works as the undefended legacy equipment.

Final Thoughts

ICMP works for the protection, and it will also keep your network secure so that ICMP should not get misuse. Here you will get all kinds of information about ICMP protocol. We hope this article will help you by providing you the correct information.