In this LAB, I am going to increase the Layer3 and Layer2 MTU and check the output. Below is our scenario:

As you can see, I have 2 routers connected to each other on their Ether1 interfaces. I am going to increase the MTU on L3 and L2, then see the result.

Let’s increase the Layer 3 MTU to 2000 and Layer 2 MTU to 2028 on interface Eth1 or R1.

Let’s change the MTU’s on R2 same as we did on R1:

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To be able to check the MTU’s, we require to put IP addresses on the interfaces Eth1 or R1 and R2 so we can ping each other.

Let’s put the IP on the R2 interface Eth1:

Now we ping from R1 to R2 with a big size packet:

Now we go to R2 and let’s capture the traffic using Packer sniffer so we see what the MTU says:

While the ping from R1 to R2 is still running, I am capturing the packets coming to Interface Ether1 on R2. If we click on the packets, we can see the MTU size:

As you see, the MTU size is 2010 as we have set it.

This is the end of this Unit; I hope you enjoyed it and see you in the upcoming Unit.

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