Router interfaces and connections

I. router interface

A vro has powerful network connection and routing functions. It can be physically connected to a variety of different networks, which makes the router interface technology very complex, the more upscale a router has more interface types, because the more network types it can connect. Vro ports include LAN ports, WAN ports, and configuration ports.
1. LAN interface

Common Ethernet interfaces include AUI, BNC and RJ-45 interfaces, as well as FDDI, ATM, Gigabit Ethernet and so on all have corresponding network interfaces, the following describes the main LAN interfaces.

(1). AUI Port
The AUI port is the interface used to connect to the coarse coaxial cable. It is a "D" Type 15-pin interface, this is one of the most common ports in the ring or bus network. The router can connect to the 10Base-5 network through a coarse coaxial cable transceiver. But more is the use of external transceiver (AUI-to-RJ-45), to achieve the connection with the 10Base-T Ethernet. Of course, you can also use other types of transceiver to connect to a fine coaxial cable (10Base-2) or optical cable (10Base-F. AUI interface 1.

(2). RJ-45 Port
RJ-45 port is our most common port, it is our common twisted pair Ethernet port. Because in Fast Ethernet also mainly uses twisted pair as transmission medium, according to the port communication rate of different RJ-45 port can be divided into 10Base-T network RJ-45 port and 100Base-TX network RJ-45 port two types. Among them, the RJ-45 port of the 10Base-T network is usually identified as "ETH" in the router, while the RJ-45 port of the 100Base-TX network is usually identified as "10/100 bTX ".

2 shows the 10Base-T network RJ-45 port, and 3 shows the 10/100 Base-TX network RJ-45 port. In fact, the two kinds of RJ-45 port is completely the same as the port itself, but the corresponding network circuit structure in the port is different, so it cannot be casually connected.
2 shows the 10Base-T network RJ-45 port, and 3 shows the 10/100 Base-TX network RJ-45 port. In fact, the two kinds of RJ-45 port is completely the same as the port itself, but the corresponding network circuit structure in the port is different, so it cannot be casually connected.

(3). SC Port
The SC port is also known as an optical fiber port. It is used to connect to the optical fiber. An optical fiber port is usually used to connect to a vswitch with an optical fiber port, instead of directly connecting to a workstation using a optical fiber. Instead, it is connected to a vswitch with a optical fiber port, such as a fast Ethernet or Gigabit Ethernet. These ports are generally available in high-end routers and are marked with "B FX", as shown in figure 4.

2. WAN Interface

As mentioned above, vrouters can not only achieve the connection between the LAN, but also the connection between the LAN and the Wan, and between the WAN. However, because the wide area network is large and the network environment is complex, the speed requirement of the port used by the router to connect to the wide area network is very high. In Ethernet, the speed requirement is generally above Mbps Fast Ethernet. The following describes several common Wan interfaces.

(1). RJ-45 Port
The RJ-45 port can also be used to establish a connection between the Wan and the lan vlan (Virtual LAN), as well as to the remote network or the Internet. If you use a router to provide routes for different VLANs, you can directly connect to different VLAN ports using twisted pair wires. But pay attention to here the RJ-45 port connected to the network is generally not very can be 10Base-T this, generally is more than Mbps Fast Ethernet. If you need to connect to a remote network through optical fiber, or connect to other types of ports, you need to use the transceiver to connect to each other. 5 is the Fast Ethernet port.

2). AUI Port
We have also discussed the AUI port in the LAN. It is a network interface used to connect to the coarse coaxial cable. In fact, the AUI port is also commonly used to connect to the WAN, however, this type of interface is rarely used in the WAN. On Cisco 2600 series routers, two WAN connection ports (6) for AUI and RJ-45 are provided, allowing you to select the appropriate type as needed.

3). High-Speed Synchronous Serial Port
In the WAN connection of the router, the port with the most applications must be counted as "high-speed synchronous SERIAL port", as shown in 7.

This port is mainly used to connect to network connection modes such as DDN, Frame Relay, X.25, and PSTN. Sometimes DDN or X.25 or other WAN connection technologies are used for leased line connection between enterprise networks. This type of synchronization port generally requires a very high speed, because in general, both ends of the network connected through this port require real-time synchronization.
4) asynchronous serial port
Asynchronous Serial Port (ASYNC) is mainly used for Modem or Modem pool connections, as shown in figure 8. It is mainly used to enable remote computers to dial in to the network through the public telephone network. Compared with the synchronous port described above, this asynchronous Port
The speed requirement is much looser, because it does not require real-time synchronization between the two ends of the network. It only requires continuous synchronization, mainly because the communication speed of the interface is low.

(5). isdn bri Port
Because the connection speed of the Internet access method such as ISDN has its own unique side, at that time, when ISDN was just emerging, it had been fully applied to the Internet connection mode. The isdn bri port is used to connect an ISDN line to the Internet or other remote networks through a router, achieving a communication rate of kbps. ISDN has two speed connection ports: isdn bri (Basic Rate Interface) and isdn pri (basic group rate interface ). The isdn bri port is a RJ-45 standard and is connected to the ISDN NT1 using a RJ-45-to-RJ-45 Express Line. The BRI shown in Figure 9 is the isdn bri port.

3. router configuration interface

The configuration ports of the vro are "Console" and "AUX". The "Console" is usually used for basic configuration of the vro through a dedicated connection with the computer, "AUX" is used for vro remote configuration and connection.

1. Console Port
The Console port uses a dedicated connection to directly connect to the computer's serial port, and uses the terminal simulation program (such as the "Super Terminal" in Windows) for local configuration of the router. The Console port on the router is mostly a RJ-45 port. As shown in figure 10, a Console Configuration Port is included.

2. AUX port
The AUX port is an asynchronous port. It is mainly used for remote configuration, dial-up, and MODEM connection. The AUX port and Console port are usually provided at the same time because they are used differently. For the interface illustration, see Figure 10 above.

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Article entry: csh responsible editor: csh