This chapter will be about the following:
1. Several ports are NIC (WAN, LAN, console, etc.)
2. Dial-up, static network, dynamic network
3. Common network devices such as routers, switches, and optical hub and cats
4. The three layer network, the network and the difference between two VLAN
The practical problem
LAN port
WAN is a wide area network gateway
LAN is a local area network
console interface: it is used to configure the switch, so only managed switches only.
DHCP Description: the router is dynamically assigned to the DHCP client IP switch
Network connection type:
1. Dial refers PPPOE also known as ADSL is provided by the carrier access account and password to log in after networking
2. Dynamic network is the superior network and then open the DHCP downstream can they can get IP
3. static IP refers to the upstream network is not turned on DHCP, an IP address to specify their needs downstream
Light cat
After the first fiber to the home, because the computer can not use the optical signal, it requires electrical or optical signals into electrical signals into optical signals devices called light cat;
Light Cat: also known as a modem, it is mainly for signal conversion, such as converting the analog signals into digital signals.
1. The individual light cat just as with the processing power of the optical signal , the Internet also need to dial-up Internet router
2. Light cat with routing devices in a home some here do not tangle household equipment found on a fiber optic device will be able to get online
Use: optical fiber insertion port, plug in the power to
If the cat-connected and the next you need to use twisted-pair (cable) connection with the router light cat
router
Common home routers we normally see the router is not just with an antenna and other similar routers and includes the switch, the switch look similar, but the port is not a multi-switch (router has a WAN port is also possible that the HUB, but more of a router)
use:
Cat-connected routing
1. Light cat's LAN port router with WAN port connection
2. Go to the router settings page,
2.1 Setting network mode (also called set PPPOE ADSL)
2.2 Enter the account password (account password to the operator)
3. Connect
Error: PPPOE error is a problem with your account password Make sure you enter the correct, sometimes accidentally entered the wrong
A router or exchange connected to a router monovalent below
1. On the main route from the LAN interface cable to the WAN port routing
2. From the routing settings page
2.1 Set network mode if the primary route turned DHCH need to choose (dynamic DHCP to obtain), or choose their own static IP assignment
3 setup is complete
Router as a switch:
1. From the routing set: DCHP off, and then change the route can not be routed with the main network with a network (routing function to prevent the object is to give the primary routing conflicts)
2. Delete prevent conflict in various configurations with the main route from the route
3. The primary route LAN port to a LAN cable from the access route
From the late route maintenance:
Remember article 1 of the route network segment, the computer from modify to use the specified IP (network segment points from the route), the gateway is usually the first segment
Then access gateway can modify the settings of the late
If the switch to the main route to obtain IP network modified or set based routing network segment
HUB
hub and routing similar, there are WAN, but work differently
One difference : HUB is a multi-port repeater, when the HUB center in the device, even if a network failure has occurred lines, it does not affect operation of other circuits, so HUB been widely used in the LAN.
Difference between the two: the router is a gateway device connected to the key network. As a hub between different networks of interconnected router system configuration based on TCP / IP body context of international Internet interconnection network.
Three differences: hub apparatus OSI physical layer belonging to the first layer, the second layer of OSI router that belongs to a data link layer device. It means that the hub transmission data only play synchronization, amplification and shaping effect on the transmission of short data frame, debris can not be treated effectively, we can not guarantee the integrity and accuracy of data transmission; and the router only transmission of data can be synchronized, amplification and shaping, can be misplaced and short frame, debris.
Distinguish four: hub is a broadcast mode, that is to say when the hub of a port to work, all other ports are able to listen to information, easy to produce broadcast storms , when the larger network when the network performance will be greatly affected. And it is possible to avoid this router, the router when the working time, only the issue request and destination ports between each other without affecting the other respective ports, so the router can be effectively suppressed conflict with isolated disease broadcast storm generated.
Use: it is currently only a LAN HUB used as a switch, I have not yet used the connection to external networks
1. backbone LAN cable is inserted into the
2. The other clients also be inserted into the LAN
switch
The difference with the switch router
https://jingyan.baidu.com/article/7908e85cda65e1af481ad2c4.html
1. router at the network layer, the IP address addressing.
2. The router can handle the "TCP / IP" protocol, the switch does not work.
3. In the relay switch layer, addressing the address "MAC" The.
4. IP routers can be given to a plurality of hosts using the same IP outside.
The switch can be connected to many hosts, different external IP.
6. The router can provide firewall, switches can not provide this functionality.
7. Switch is doing to expand LAN access point, allowing more computers into a local area network connected.
8. The router is used for the gateway, which is used to connect different networks.
The router can automatically assign IP and dial-up virtual local area network. The main switch and the data network for distributing only expansion port.
Three networks and network layers
Hereinafter refers to a network switch network port
Layer 2 network networking capabilities are very limited, generally only a small LAN; three networks can be set large networks.
Only when used in large-scale distribution of three switches , very expensive. Common switch is the switcher , only recognizes the MAC address, did not know the IP address (the computer responsible for conversion), so called switcher , not the route;
three switches , Cisco brand, support VLAN, MAC address not only recognize, but also can MAC frame IP addresses
identified, routing, powerful and complex, expensive, a switch can be divided into N number of
network segments, but also the N three switches distributed multi-network segment, called VLAN.
<------------------- --------------------- problem>
The company intranet service upgrade router to replace a problem with a system like never touched mainly on their own network operation and maintenance is just too little knowledge about fur, encountered the most problems is not assigned IP routing can not cause the computer to get IP
Which not obtain IP The two main problems encountered are not assigned ip's
1. Error of the non-LAN port as a LAN (eg TP router has one or more WAN port and multiple LAN ports and a Gigabit Ethernet port, which is also a Gigabit LAN port and, but do not know why one thousand Katherine port IP address is not assigned to the computer (which is estimated as a backup port data port exists))
2. If it is set to three network switches for each port requires its own IP network segment from a given port
Also note that loop between routers, the loop will result if there is no Internet access