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8 votes
3 answers
7k views

Does a switch understand packets? If yes, what is the frame terminology for?

I was a little confused between packet and frame. The confusion was based on, if a switch is a layer 2 device, how does it reads a packet from a layer 3 device, and where is the 'frame' thing which is ...
Taha's user avatar
  • 83
5 votes
5 answers
560 views

What blocks a computer from another network in the same switch from answering an ARP request?

Let's suppose I have 3 computers A, B and C connected to the same switch with only the native VLAN active. A and B belong to the same network, let's say that their IP addresses are 192.168.1.1/24 for ...
caiokameda's user avatar
5 votes
2 answers
7k views

How does a layer-2 switch work with UDP?

If UDP and/or TCP send packets via IP to an Internet Protocol Address, how can a layer-2 switch forward these? Is this possible or do you need a layer-3 switch?
user_ABCD's user avatar
  • 634
4 votes
3 answers
1k views

Collision domain question

I'm studying for my CCENT exam, and not quite sure why the book (official Cisco) says that there are 5 collision domains in this example. Isn't it supposed to be 4? The hub on the left, the hub in the ...
PowerTowerDad's user avatar
4 votes
1 answer
8k views

What is the purpose of native VLAN on a trunk link?

Most VLAN articles I've read recommend avoid using VLAN1 for ports with untagged traffic (aka access ports). I've heard enough of this nonsense. Except for the reserved values of 0x000 and 0xFFF, a ...
Livy's user avatar
  • 433
2 votes
6 answers
3k views

Is a "LAN" a layer 2 or a layer 3 concept, in TCP/IP?

I think my question is purely theoretical and a matter of definitions; it derives from the fact that a L2-switch with VLAN capabilities is able to "create" different virtual LANs, and thus I am led to ...
Maurizio Carcassona's user avatar
8 votes
2 answers
13k views

Why each and every single port on Layer 2 switches need to have it's own MAC address?

A switch doesn't alter the frame, and source/destination mac addresses remain how sending host specified them,so let me say it again Layer 2 Switching never changes the frames means no changes in MAC ...
user7741's user avatar
  • 435
8 votes
6 answers
5k views

How Does A Layer 2 Switch Differentiate Between Different Networks?

I know that different IP-based networks can be connected to the same layer-2 switch. and I know each network's nodes can communicate just fine, however, no normal traffic can occur between two nodes ...
Shadi's user avatar
  • 285
1 vote
4 answers
3k views

Communication between different VLANs

In my previous understanding, there is no way to communicate between two VLANs using only layer 2. After all, this is the purpose of having VLAN. I found a forum that claims the following. 1.VLANs can ...
jacky chong's user avatar
0 votes
3 answers
346 views

Propagating Static MAC Addresses

I have a situation where I need to place a static MAC on a switch as the server in question does not generate any outbound traffic. This static MAC seems as if it will work for hosts on the same ...
o8uijoipjasdfjiloasdfjl's user avatar