Your CCNA scientific tests are going to consist of a large amount of information regarding switches, and forever rationale. when you don’t realize fundamental switching concept, it is possible to’t configure and troubleshoot Cisco switches, possibly within the CCNA exam or in the real environment. That goes double for trunking!
Trunking is solely enabling two or more switches to communicate and ship frames to each other for transmission to remote hosts. There are two significant trunking protocols that we must know the small print of for Examination good results and actual-planet results, but before we get towards the protocols, Enable’s examine the cables we need.
Connecting two Cisco switches requires a crossover cable. As you are aware of, there are actually eight wires inside an ethernet cable. Within a crossover cable, four from the cables “cross over” from one particular pin to a different. For many more recent Cisco switches, all you'll want to do to create a trunk is join the switches with a crossover cable. By way of example, 2950 switches dynamically trunk after you connect them with the right cable. If you employ the incorrect cable, you’ll be there some time!
There are 2 distinct trunking protocols in use on now’s Cisco switches, ISL and IEEE 802.1Q, commonly often called “dot1q”. You'll find 3 principal distinctions concerning The 2. First, ISL is actually a Cisco-proprietary trunking protocol, where dot1q will be the field conventional. (Those of you new 토토사이트 to Cisco testing must get accustomed to the phrases “Cisco-proprietary” and “sector typical”.) When you’re Functioning in a very multivendor ecosystem, ISL will not be a sensible choice. And Despite the fact that ISL is https://en.search.wordpress.com/?src=organic&q=먹튀검증 Cisco’s own trunking protocol, some Cisco switches operate only dot1q.
ISL also encapsulates the complete frame, raising the community overhead. Dot1q only spots a header around the frame, and in a few instances, doesn’t even do this. There exists a lot less overhead with dot1q as compared to ISL. That causes the third major big difference, how the protocols function While using the native vlan.
The native vlan is simply the default vlan that swap ports are put into if they are not expressly positioned into A further vlan. On Cisco switches, the native vlan is vlan 1. (This may be changed.) If dot1q is functioning, frames that will be despatched across the trunk line don’t actually have a header placed on them; the remote swap will suppose that any frame which has no header is destined for the indigenous vlan.
The problem with ISL is that is definitely doesn’t realize what a native vlan is. Each and every frame are going to be encapsulated, regardless of the vlan it’s destined for.
Switching theory is a huge component of one's CCNA experiments, and it can look too much to handle to start with. Just break your experiments down into more compact, a lot more workable components, and soon you’ll see the magic letters “CCNA” guiding your name!