TASK: “Setting Up Network Topology for System A, B & C where A can ping B & C, but both B & C can’t ping each other”
Network topology is the arrangement of the elements of a communication network. Network topology can be used to define or describe the arrangement of various types of telecommunication networks, including command and control radio networks, industrial fieldbusses and computer networks.
Routing:-
According to Wikipedia “Routing is the process of selecting a path for traffic in a network or between or across multiple networks. Broadly, routing is performed in many types of networks, including circuit-switched networks, such as the public switched telephone network, and computer networks, such as the Internet.”
Routing Table:-
A routing table is a kind of database where all the routing rules or information are stored from device to device. According to Wikipedia, “In computer networking a routing table, or routing information base, is a data table stored in a router or a network host that lists the routes to particular network destinations, and in some cases, metrics associated with those routes.”
Requirements:-
- No of Systems (Virtual / Real): 3 (three)
- No of Router (Internet Connectivity optional): 1 (one)
We can also use Virtual Machines with bridge networking connected with mobile hotspot with an active internet connection.
“The mobile hotspot also works as a Router and Switch”
Network Configuration:-
I have assigned the following IP address to these VMs :
System A:
IP: 192.168.43.1 Netmask: 255.255.255.0
System B:
IP: 192.168.43.2 Netmask: 255.255.255.0
System C:
IP: 192.168.43.3 Netmask: 255.255.255.0
Modifying Routing Table in System A ,B & C:
System A:
Assign Network Name →
Check IP and Netmask of System A (Network Card enp0s3):
System B:
Assign Network Name →
Check IP and Netmask of System B (Network Card enp0s3):
System C:
Assign Network Name →
Check IP and Netmask of System C (Network Card enp0s3):
According to the new rule or Routing Table, when B & C try to ping 192.168.43.XXX range IPs, they won’t work except 192.168.43.1 which is the IP of System A, which means both B & C can be ping by System A, but B & C can’t ping each other according to the routing table. Genmask of /31 is describing that, when B or C try to connect with 192.168.43.1, it will work as Point to point connection. That means, on both B & C, when both the system try to ping System A, according to Point to Point and CIDR /31, only 2 hosts can be scanned in this range, including 192.168.43.1 and system B IP 192.168.43.2 itself and in case of C, IP 192.168.43.2 and 192.168.43.1.
Result:
1. Ping A — C : Successful
2. Ping A — C : Successful
3. Ping B — C : Failed
Finally, the conclusion is that we can achieve the solution using the Point to Point Routing rule in the Routing table of B & C.
Note: This particular scenario and the solution is subject to research work, the article or solution might be changed in case of any update or improvement.
That’s all. Thanks for reading!
Published By
Sheikh Aafaq Rashid
Originally published at https://www.linkedin.com.
