If you have a problem with the router, please ask an expert to answer it!!

PPP was designed for serial communication, and now it is combined with Ethernet to become a technology for relaying PPP frame information in an Ethernet network. Also known as PPP over Ethernet, PPPoE protocol. The PPP protocol is not compatible with Ethernet.

A MAC address is a physical address solidified in the serial EEPROM on a network card, typically 48 bits long. Ethernet switches exchange and transmit packets based on the MAC source and destination MAC addresses in the packet header.

As the most important device in the network layer, the security of the router is the concern of many network administrators, and the author here is just talking about how to improve its security from the perspective of management. When managing routers, we generally use telnet commands to manage remotely through the VTY port of the router, which has its own security vulnerabilities, any client can guess your password, or use brute force tools to crack it remotely. If we only allow a certain network segment or a certain IP address to be remotely managed, and other machines are not allowed to log in remotely, this will greatly enhance the security of the router.

The following author takes the Cisco router as an example to introduce its configuration method.

Start by creating an access control list in global mode:

router(config)#access-list 3 permit host

Only this machine is allowed to access, and the implicit condition is that other machines are not allowed to access it.

Next, apply this rule to the VTY port:

router(config)#line vty 0 4

router(config-line)#access-class 3 in

Apply the rule to the 0 4 port of VTY, which can be defined by yourself.

After this configuration, the router only allows access to this machine, and other machines have no access. But we are not so flexible in management, and can only be managed with fixed machines, so we should find a balance between management and security, so that the router is both easy to manage and secure, for example, a certain network segment can be allowed to be managed.

There is a problem with the hair bag, but it is relatively rare.

The MAC address is the physical address of the network card, and the existence of the network card is based on this address. The relationship between the MAC address and the IP address of the network card is somewhat similar to the relationship between the **IP address and the domain name, and the latter exists mainly to help people remember. Because it is difficult for general users to change the MAC address of the network card, the network hardware with network management function will use this address for centralized management, and use the MAC address to complete the identification of network users, the management of Internet access rights, and the clarification of services and responsibilities.

ADSL dial-up is originally PPPoE, and the IP allocation principle of PPPoE is DHCP

It's not that it's changed from DHCP to PPPOE.

There is a wizard on the router management page.

If you are from Henan or Shandong, ordinary routers may not be able to get on.

To put it simply:

The function of DHCP is to allocate IPPPPoE to access router LAN end devices, which is a dial-up protocol commonly used in ADSL.

MAC filtering: all network card routing hubs and other devices that can access your router have a unique physical address MAC address in the world, in order to avoid some unauthorized illegal access to network devices, you can set MAC filtering, that is: enter the MAC address of the network device you allow, and all other filtering - access is not allowed.

PPPoE: Point to Point Protocol over Ethernet.

Chinese definition: Point-to-point protocol over Ethernet.

MAC: Each NIC has a unique physical identification number, which is commonly referred to as the physical address of the NIC.

MAC filtering: It is to filter through the MAC settings, yes, the relevant MAC can not or allow access, this method can control the illegal computer to connect to the Internet, even if he secretly changes the IP.

Basic maintenance:1Good ventilation and heat dissipation, less dust, good grounding, stable power supply, waterproof, fireproof and lightning protection.

3.Make full use of relevant security settings, do a good job in the permission management of the internal network, and save the manual in case of emergency.

Hehe, you are really thirsty for knowledge, look at the manual, follow the above settings and you can use it.

Original meaning: point to point protocol over ethernet

Chinese definition: Point-to-point protocol over Ethernet.

Mac filtering, as long as the filtering is turned on, the restricted machine will not be able to access the Internet.

MAC filtering is the physical NIC address. It's the network card you use to access the Internet.