Overlapping VLSM Subnets

Overlapping VLSM subnets can cause issues in a network, as they can lead to routing problems and connectivity issues. It is important to avoid overlapping subnets when configuring VLSM to ensure proper network functionality.

To avoid overlapping subnets, it is recommended to plan the IP addressing scheme carefully before implementation. This involves dividing the network into smaller subnets based on the number of hosts required on each segment, and selecting an appropriate subnet mask for each subnet.

Here’s an example of how overlapping subnets can cause issues:

Suppose we have two networks, Network A and Network B, with the following IP addressing scheme:

Network A: 192.168.1.0/24

Network B: 192.168.1.128/25

In this case, Network B overlaps with the subnet of Network A. This can cause issues with routing, as packets destined for Network B may be sent to the wrong subnet.

To avoid this issue, we can reconfigure the IP addressing scheme to ensure that there is no overlap between subnets. For example:

Network A: 192.168.1.0/25

Network B: 192.168.1.128/25 In this case, each network has its own unique subnet, and there is no overlap between subnets. This helps to ensure proper routing and connectivity in the network.