ICMP sends the error, warning, and status of a particular activity. The ICMP message can be either a success or failure notification while communicating with another Networking device.  The IP Addresses of all the connected devices will have an entry in the router log. ICMP is a Network Layer protocol. There are many layer-management protocols in the Network Layer. It is a part of the suite TCP/IP that takes care of the messaging functions. ‘Self 2 WAN ICMP Type B Detected’, is an Error message in the router log, that indicates a malicious attack in the network, immediately by shielding the network using its default Firewall.

How to Rectify the Self2 WAN ICMP Type B Detected Error Message?

Check the remote access (if you logged in remotely)

Update Router Firmware (the firmware is to be updated to avoid attacks)

Update Antivirus software (should be up to date)

Examine the Firewall Configuration (to be configured to protect from malware attacks)

Reset The Router (If you are at work from home)

Consult Network Admin  (If you are in an office)

Change the IP Address (ask the Internet provider to assign a new one)

ICMP

Internet Control Message Protocol is used to send the message indicating the status of any operation done over the Internet. Any networking device that uses the TCP/IP, has access to ICMP to send messages through the ICMP. 

Router Logs

Each ICMP message consists of three fields, Type, Code, and Checksum. Two types of ICMP messages are:-

Error-reporting

 It indicates that the router is encountering a problem when transferring the data packets.

Query messages

This message helps the host to get information about another host.

How to check the Router Log?

The Router Log is a detailed record of the activities performed, like, websites one has accessed, attempted to access, etc.  It also shows all other router activities finished. There is a maximum limit of 256, which can be stored in the activity log. There is no log entry for the trusted user. 

To Check the Router Log

Each entry in the Router log consists date and time 

Source IP (IP Address of the initiating device)

Target address (IP address of the website visited)

Action (The operation performed, whether accessed or not)

Clear Log

Log in to the router settings through the browser from the computer or mobile using the IP Address of the Router (sometimes username and password are being asked).

Select  ‘ADVANCED’

Select ‘ADMINISTRATION’

Select ‘LOGS’  (sometimes, SYSTEM LOG or  HISTORY)

Then the appropriate option from,  REFRESH, CLEAR LOG, or SEND LOG, can be selected as per convenience.

Automatic Clearing of Router Logs

The router automatically clears the Logs one at a time. from the file here router logs are saved. When the size has become the maximum allowed limit, it starts removing the oldest to make space for the latest entry. Log entries depend on how much the usage of the router.       

WAN

A Wide Area Network is a telecommunication network that extends to a large-scale geographical area. All the smaller networks are combined through WAN so that two nodes placed at two locations can communicate with each other.

Components of WAN

Different physical devices are connected to make a WAN.

Edge Devices

WAN Router, Layer-3 Switch, or Modem

Connections 

Fiber optic cable, Wireless (through VPN), Satellite, or Microwave signals

CPE 

Customer premises equipment can be any terminal or end-user device, connected with the communication carrier

Routers

A Router is a special-purpose device dedicated to the task of interconnecting networks. The router is the device that works in the Network Layer. A router transfers the data packets from one network to another by looking into the router table. The router table consists of IP Addresses. The routing table is created and updated dynamically.

Different Routers

Routers are classified based on the functions they perform::

Core Router

Wireless Router

Wired router

Edge Router

Virtual Router

ICMP Error Messages

The error code is any number range,0 to 255. A few error messages are shown below: 

 The ICMP generates a message when an activity gets completed. A router is a networking device used in WAN, that establishes the transfer of data packets from source to destination. ICMP creates error messages or notifications about the activities of the router. These messages are stored in the limited space in the router. The log can be cleared or it will be done automatically when the limit is reached. The ICMP errors can be solved by updating the router software or taking additional actions.

What is meant by the OSI model?

The OSI, Open System Interconnection Model, is a conceptual model developed by ISO, to understand the functions of a communication system.

What is ‘Self2WAN ICMP Type B’?

The message conveys that the firewall inside the router is protecting the network from a potential malware attack.

What is a firewall? 

A firewall is a network security system that controls the network traffic based on the security rules and protects the network from intruder networks.

What is ipconfig?

The command ‘ipconfig’ at the command prompt shows the IP Address of the Router.