I am a student of networking and have a question. I am currently doing an internship / project at a school where they have 3 buildings. I will name them for now
- A (subnet 172.16.x.x) --> Each with their vlans
- B (same as A)
- (subnet 172.20.x.x) --> With each their vlans
In building A and C there are 2 large Layer 3 switches. So the network is connected in such a way that first goes from building A to building B via a wireless antenna connection. This arrives in building B on an L2 switch.
Then in building B you go to an L3 switch which so goes to building C and so on.
So now I am wondering on the coreswitch at A there is a vlan80 defined for the wireless connection.
vlan:
interface vlan-interface80
ip address 192.168.80.1 255.255.255.252
So there is a port taged with vlan80 for all traffic for subnet 172.20.x.x. Via static route.
Interface:
interface GigabitEthernet2/3/0/47
port link-mode bridge
port access vlan 80
Route:
ip route static 172.20.0.0 255.255.0.0 192.168.80.2
So this traffic arrives on the L2 switch in building B, but how does the L2 switch determine that the incoming taged vlan80 packet should be forwarded to the L3 switch in building B? Does it automatically forward this to all the port where taged vlan 80 is or does it look in its cam table for that? I have already looked up all kinds of things, but no one has yet provided me with a clear and ready answer.
L2 in building B
vlan 80
name "Straal"
untagged 21-22
tagged 1,6,23-24
no ip address
exit
This might be a silly question, but hopefully someone can help me. Thanks in advance.