Inter Vlan communication without Firewall

[Asfandyar70754]

Hey guys,

Hope you are doing well.

So I have been mostly doing network security in my career and never really got a chance to do a campus Lan/switching project and recently I thought to create a campus lan on lab, so most of my concepts got refreshed. 

But I got a bit confused in inter vlan communication, I had a concept if you want to inter vlan communication you will have to explicitly configure ACL on firewall/L3 device, but right now I build a lab(3 Tier Architecture) without a Firewall, and I configured 2 SVIs10.0.0.1 ,20.0.0.1 on my core Switch. So I had couple of PCs on Access Sw in their seperate vlans respectively and to my surprise they were able to ping each other.

Can you guys explain it a bit.

Thanks

[balaji.bandi · Accepted solution]

Yes, your understanding is correct, Layer 3 Switch  (not a Firewall) as soon as you enable ip routing, the networks in the Layer3 switch able to communicate with each other since they are aware of the networks in the same routing table of Layer 3 switch.

If you like to restrict between Inter-VLAN then you need to add ACL to prevent access to each other.

Firewall different - since default FW nature os deny any (until it was mention as a policy to allow each other)

make sense?

[Asfandyar70754]

Absolutely Balaji, thanks a lot.

Got it