Hi @mfalfirasi,
PC1-IT is in the IT VLAN (VLAN 11), and PC1-Marketing is in the Marketing VLAN (VLAN 12). They’re in different VLANs and subnets and this means their traffic needs to be routed. Your lab is already setup to handle this through the SVIs configured on the Layer 3 switch (SWML). If you need to find the IP address of the SVI for VLAN 11 and VLAN 12 you can do so by accessing the CLI terminal of the SWML switch and using command 'show ip interface brief' from privileged exec / enable mode.
You're missing the default gateway configuration on the PCs. The PCs don’t know where to send traffic destined for other subnets. It's due to how the binary AND operation works and general operations of IP.
This is what you need to do:
Set the default gateway on PC1-IT to the IP address of the corresponding VLAN's SVI. The SVI is configured on the switch 'SWML'
Set the default gateway on PC1-Marketing to the IP address of the corresponding VLAN's SVI. The SVI is configured on the switch 'SWML'
This needs to be done under the GUI on the Desktop PCs. Specifically, go to Desktop > IP Configuration tab on each Desktop PC
The result should be that the MLS (Layer 3 switch) called SWML can handle inter-VLAN routing which is needed for communication to work.
Let me know if that works or you need further help. I have been a little vague in the steps but hopefully is enough for you to figure out the rest. If not, let me know and can give you more specific instructions.
Hope that helps!
