Layer-3 vswitch competition vro

Both layer-3 switches and routers work on the layer-3 network and forward data packets based on IP addresses. Many network administrators are not very clear about the differences between the two. This article will briefly introduce the differences between the two technologies.
Routing Technology
There is a route table inside the router, indicating where to go if you want to go somewhere. The router receives a packet from a port. It first removes the packet header of The Link Layer (unpacks), reads the destination IP address, and searches for the route table. If you can determine where to send the next packet, the packet header (Package) at the link layer is added to forward the packet. If the next address cannot be determined, a message is returned to the source address and the packet is discarded.
Layer-3 Switching Technology
Compared with the traditional concept, layer-3 switching is proposed. The traditional switching technology operates on the Layer 2-data link layer in the standard OSI network model, while the Layer 3 switching technology implements high-speed packet forwarding in the network model. Simply put, layer-3 switching technology is layer-2 switching technology + layer-3 forwarding technology.
Comparison of the two technologies
The most fundamental difference between the two is that a layer-3 Switch also has a "routing" function. A layer-3 switch is not the same as a router, nor can it replace a router. The routing technology and layer-2 switching seem a bit similar. In fact, the main difference between routing and switching is that switching occurs on the layer-2 (data link layer) of the OSI reference model, while routing occurs on the layer-3. This difference determines that different control information needs to be used for routing and exchange during data transmission. Therefore, the two methods to implement their respective functions are different.
Specifically, there are the following differences:
1. The main functions remain unchanged
Although both layer-3 switches and routers have routing functions, they cannot be equivalent. As many broadband routers have not only the routing function, but also the switch port and hardware firewall function. However, they cannot be the same as switches or firewalls. Because the main function of the router is still the routing function, other functions are only the additional functions, the purpose is to make the device wider and more practical. The same is true for the layer-3 switch. It is still a switch product, but it has some basic routing functions. Its main function is data exchange. That is to say, it has both data exchange and route forwarding functions, but its main function is data exchange, and the router only has the main function of route forwarding.
2. Different Places of use
L3 switches are mainly used for simple LAN connections. Because of this, the routing function of a layer-3 switch is usually relatively simple, and the routing path is far less complex than that of a router. It is mainly used in the LAN to provide the fast data exchange function, it is suitable for applications with frequent LAN data exchanges. Vrouters are different to meet different types of network connections. Although it is also suitable for LAN connections, its routing functions are more reflected in the interconnection between different types of networks, for example, the connection between the LAN and WAN and the connection between networks of different protocols. Therefore, the router is mainly used between different types of networks. Its main function is route forwarding, the ultimate goal is to solve the connection of various complex routing path networks.
3. Different Data Processing Methods
Generally, a vro performs Packet Exchange by a microprocessor-based software routing engine, while a layer-3 Switch performs Packet Exchange through hardware. After a layer-3 switch routes the first data stream, it will generate a ing table between the MAC address and IP address. When the same data stream passes through again, the table is directly routed from the second layer instead of the second layer, which eliminates the network delay caused by router selection and improves the efficiency of packet forwarding. At the same time, the routing lookup of a layer-3 switch is for data streams. It uses the caching technology and ASIC Technology to easily implement it. Therefore, it can greatly save costs and achieve fast forwarding. Vro's forwarding adopts the longest matching method, which is complicated. It is usually implemented using software, and the forwarding efficiency is low.
To sum up, there are major essential differences between layer-3 switches and routers. For multi-subnet connections in a LAN, it is best to use a layer-3 Switch, especially in environments with frequent data exchanges between different subnets. Although a router has powerful routing functions, its packet forwarding efficiency is far lower than that of a layer-3 switch, which is more suitable for interconnection between different types of networks with less frequent data exchanges.