Basically a layer 2 switch operates utilizing Mac addresses in it's caching table to quickly pass information from port to port. A layer 3 switch utilizes IP addresses to do the same.
While the previous explanation is the "What", for folks in networking the following "How" is far more interesting.
Essentially, A layer 2 switch is essentially a multiport transparent bridge. A layer 2 switch will learn about MAC addresses connected to each port and passes frames marked for those ports. It also knows that if a frame is sent out a port but is looking for the MAC address of the port it is connected to and drop that frame. Whereas a single CPU Bridge runs in serial, todays hardware based switches run in parallel, translating to extremly fast switching.
Layer 3 switching is a hybrid, as one can imagine, of a router and a switch. There are different types of layer 3 switching, route caching andtopology-based. In route caching the switch required both a Route Processor (RP) and a Switch Engine (SE). The RP must listen to the first packet to determine the destination. At that point the Switch Engine makes a shortcut entry in the caching table for the rest of the packets to follow. Due to advancement in processing power and drastic reductions in the cost of memory, today's higher end layer 3 switches implement a topology-based switching which builds a lookup table and and poputlates it with the entire network's topology. The database is held in hardware and is referenced there to maintain high throughput. It utilizes the longest address match as the layer 3 destination.
Now when and why would one use a l2 vs l3 vs a router? Simply put, a router will generally sit at the gateway between a private and a public network. A router can perform NAT whereas an l3 switch cannot (imagine a switch that had the topology entries for the ENTIRE internet!!). In a small very flat network (meaning only one private network range for the whole site) a L2 switch to connect all the servers and clients to the internet is probably going to suffice. Larger networks, or those with the need to contain broadcast traffic or those utilizing VOIP, a multi network approach utilizing VLANs is appropriate, and when one is utilizing VLANs, L3 switches are a natural fit. While a router on a stick scenario can work, it can quickly overtax a router if there is any significant intervlan traffic since the router must make complicated routing decisions for every packet that it recieves.
Layer 2 (L2) switches work on Data-Link layer of OSI Model. Layer 2 devices uses MAC Addresses to communicate.
Layer 3 (L3) switches work on Network Layer of OSI Model. Layer 3 devices uses IP Addresses to communicate.
How do L1, L2, and L3 work
If L1 is parallel to L2 and L2 is parallel to L3 then L1 is parallel to L3.
Unscrewing any light bulb in series will result in the others turning off. If they are in parallel, unscrewing one will have no effect. For example, say we have lights bulbs L1, L2, and L3, where L1 and L2 are in parallel and L3 is in series with L1 and L2. If L1 is unscrewed: L2 and L3 will stay lit. If L2 is unscrewed: L1 and L3 will stay lit. If L3 is unscrewed: L1 and L2 will turn off.
NO.
A voltage of 277 is the line to neutral (ground) voltage of a 480 volt wye three phase system. L1- N, L2 - N and L3 - N will give you 277 volts. L1 to L2. L2 to L3 and L3 to L1 will give you 480 volts.
L1, L2, and L3
No, 277 volts is the line to neutral of a 480 volt wye three phase system. L1- N, L2 - N and L3 - N will give you 277 volts. L1 to L2. L2 to L3 and L3 to L1 will give you 480 volts.
Usually between L2-L3 or L3-L4.
If there are given two parallel line L1 and L2, and a third line L3 that is perpendicular to L1, then the line L3 must also be perpendicular to L2.
l1 is in motherboards l2 is on processor newer processor has l3 too
If the motor wire numbers are L1, L2 and L3, it is not a single phase motor. It is a three phase motor. Also for future reference, a 220 volt single phase motor does not use a neutral.
It uses L1 L2 and L3.