Layer 2 Attack on Network

Hello Everyone ! I'm new to the null-byte forum. I read a lot on null-byte but didn't find some Layer 2 attack. I work for with a company who tell me to find some vulnerability on their Network. The only Attack that I've read are "Vlan Hopping", "Arp spoofing/Poissoning", "The Famous MITM" and "Mac flooding"

I Set up a "Hacking Lab" to test all those kind of attack but "Mac Flooding" & "Vlan Hopping" Did not work. So I was wondering if there is a way to access VLAN ( mostly on Cisco material ).

I you can lead me to some Layer 2 attack that will help me a lot.

If you don't want to Lead me to some Layer 2 attack, I'll understand and try have a better understanding of the material and find some vulnerability by myself.

But I won't refuse help :)

Thank for reading me and sorry for my poor english.

-Kwery