Router configuration basics: detailed introduction of various router Components

To complete router configuration, you must have a deep understanding of all aspects of the router, especially the router composition and detailed knowledge of various components. Before configuring a vro, you should first understand its structure and vro configuration.

Processor

Like other computers, a vro running for 10 s also contains a "central processor" (CPU ). Vrouters of different generations and models have different CPUs. The vro processor is responsible for the work required to process data packets, such as the tables required to maintain routes and bridge connections, and to make route decisions. The speed at which the router processes data packets depends largely on the type of the processor.

Memory

All computers are installed with some form of memory. Vrouters mainly adopt four types:
Read-only memory (ROM ).
Flash memory.
Random Access Memory (RAM ).
Non-volatile RAM (NVRAM ).

Among all types of memory, RAM is the only memory that will lose its content when the router is started or the power supply gap occurs. In the introduction below, we will briefly describe the main usage of each memory type of the router. ROM stores the boot software of the router. This is the first software running on a vro. It is responsible for bringing the vro into normal working state. Some routers save a complete set of IOS in the ROM, so that when another IOS cannot be used. For emergency purposes. Generally, ROM is installed on one or more chips and welded to the motherboard of the router.

Flash memory is mainly used to save the software for 10 s to maintain the normal operation of the router. If the router is installed with flash memory, it is the default position for guiding the router's 10 s software. If the flash memory is sufficient, multiple IOS images can be saved to provide multiple startup options. Flash memory is either implemented on the SIMM of the motherboard or a PCMCIA card. RAM is widely used and cannot be listed here. But there are two things worth mentioning: IOS system tables and buffering. IOS uses RAM to meet all its conventional storage needs. NVRAM is mainly used to save the router configuration data read by IOS when the router is started. This type of router configuration is called "STARTUP configuration ".

Interface

All routers have interfaces ). We have listed some Interface Types supported by routers. In a router using I0S, each interface has its own name and number. The full name of an interface consists of its type identifier and at least one number. The ID starts from 0. For vrouters whose interfaces have been fixed or which use modular interfaces, only the host can be changed after the interfaces are closed, there is only one number in the full name of the interfaces, in addition, they are numbered in the physical order of the vro. For example, Ethernet0 is the name of the first Ethernet interface, and serial is the name of the third serial port.

If the vro supports "online insertion and deletion", or has the ability to dynamically (without disabling the vro) change the vro configuration of the physical interface (hot swapping of cards ), the full name of an interface should contain at least two numbers, separated by a forward slash (/) in the middle (/). The first digit represents the slot number, the interface processor card will be installed on the slot, and the second digit represents the port number of the interface processor. For example, in a 7507 vro, Ethernet5/0 represents the first Ethernet interface located in slot 5-assuming that slot 5 is inserted with an Ethernet interface processor card. Some routers also support "universal interface processor" (VIP ). An interface name on the VIP consists of three numbers, which are also separated by a forward slash (/). The interface number is in the format of "slot/port adapter/port ". For example, Ethemet4/0/1 indicates the second Ethernet interface of the first port adapter in slot 4. These numbers may be confusing for the first time. But don't worry. There is a way for the router to tell us the full name of all its interfaces.