Routing mode and bridge mode
earlier domestic ADSL line access mode is a bridge, and a computer with ADSL MODEM, a fixed IP address assigned in the computer, the boot device access to the Internet can access the central office. But this does not start when the user access, IP is not being used, wasteful currently growing lack of public IP network resources, resulting in the ADSL PPPoE dial-up access.
PPPoE dial allows the user switched dial-up access infrastructure equipment, a dynamically assigned public IP network by the central office device, and the public IP network to tension eased. Current domestic ADSL Internet, substantially is PPPoE dial-up way. After PPPoE dial-up appears, ADSL access equipment --ADSL MODEM (ADSL modem) will have a new sibling product called ADSL ROUTER (ADSL router). This device has the most basic ADSL MODEM bridge function, so the individual products is also called ADSL BRIDGE / ROUTER (ADSL bridging routers), commonly known as "Dailu of ADSL MODEM." ADSL ROUTER PPPoE dial-up software comes with, and can provide DHCP services, RIP-1 routing functionality, it is a small amount of graft function of the router. However, PPPoE dial-up is not to say there is no bridge, like a common type of network: ADSL MODEM + PPPoE dial-up software (such as EnterNet 300). There are some places still the main push of telecom operators in general ADSL MODEM, so there is no routing function, in fact, does not encourage users to "front-line multi-machine." But now the ADSL access equipment manufacturers competition is really fierce, so ADSL MODEM has been basically shut down, and switch to the production of ADSL ROUTER, which is why most of the ADSL MODEM are now called "Router", that is, ADSL access the device is basically ADSL ROUTER.
Due to the different network scheme, ADSL ROUTER have a mode of bridging mode and routing mode.
If there is a small home or SOHO user client, you can directly use PPPOE ROUTED-- routing mode to be PPPoE dial-up and ADSL ROUTER by the route. You can also use RFC 1483 BRIDGED, then access PC, run PPPOE dial-up software to dial-up, broadband router or access on a PC, the built-in dial-up broadband router PPPOE dial-up tool.
If the number of large multi-user environment, the client, such as: Internet cafes, businesses, communities, often in the form of ADSL ROUTER plus network broadband router, then the majority will make ADSL ROUTER work in bridge mode to a broadband router dial function, and take the route of the work, which is due to lower ADSL ROUTER routing capabilities, there will be performance degradation or crash failure to produce the requested routing process large number of clients. So, bridging mode and routing mode for the fact it's in ADSL ROUTER.
What is the bridge mode
ADSL ROUTER bridge mode there is a formal professional name is called RFC1483 bridge. RFC1483 standard in order to achieve multi-protocol network layer packets are encapsulated in the ATM network and the development of ATM technology is now widely used in the package becomes the standard multi-protocol processing of data packets over the ATM network.
RFC1483 simulated Ethernet bridging, network layer packet that were LLC / SNAP encapsulation on the data link layer. After completion of the RFC1483 ATM encapsulation of Ethernet frames in the ADSL Modem transparently transmit packets over PVC PVC client and the network infrastructure. RFC1483 bridge of ADSL access mode is the most basic form of ADSL broadband access, but also the basis for other access modes, the general ADSL SPEED ROUTER factory default also bridged mode. ADSL ROUTER factory default value for a single computer bridge manner, is placed in its current operating mode "BRIDGE ENABLE (bridge enabled)." In the pure bridge mode, ADSL ROUTER just an ordinary bridge, its function is relatively simple. Typically requires a proxy server or gateway device in the local area network communication coming together and then connected to the external network. PPPoE dial-up software to be run on the proxy server or gateway device. Bridge mode may be assigned a fixed IP Administrator may be blended with the dial-up software can be set to automatically obtain or assign a fixed IP set in the PC side.
What is the routing mode
ADSL ROUTER routing mode generally refers to the operation mode in the ADSL ROUTER "ROUTER ENABLE (Enable Routing)", which has PPPOE dialing, NAT, RIP-1 and other small routing function.
PPPoE stands for Point to Point Protocol over Ethernet (LAN-based point to point protocol). It is based on two widely accepted standards namely: LAN Ethernet and PPP PPP Protocol. With ADSL ROUTER in RFC1483 bridging encapsulation packet sent from the terminal to be PPP LLC / SNAP encapsulation, PVC establish a connection between the connecting ends at the network side ADSL Modem broadband access server, to achieve dynamic PPP access . For service providers who do not need to spend money to do large-scale transformation, set the IP address binding and other user support line mode. This makes the PPPoE broadband access services has more advantages than other protocols. Thus becoming the best choice for broadband Internet access.
In routing mode, ADSL ROUTER is a barebones independent, with its own PPPOE dial-up and do NAT, became a stand-alone gateway does not require a dedicated machine is turned on and set to share Internet access gateway for other people to do, or do not need broadband router gateway, directly connected to the LAN switches can be shared online. The benefits of open routes: (1) do not have to dedicate a computer to do the server, any computer can boot the Internet. (2) unique IP address obtained by the ADSL ROUTER, all external attacks by acting on the ADSL ROUTER, protects computers to share access to a certain extent.
ADSL ROUTER routing mode is enabled routing mode, you can save the proxy server software and dial-up or broadband router. However, due to hardware limitations condition, ADSL routing capability only applies to only a few computers sharing applications such as home, dormitories and other ultra-small network. For businesses easily dozens, even hundreds of application status, ADSL routing would be difficult to perform competently. In the enterprise environment, ADSL runs in route mode, there may be some problems, such as: frequent ADSL link to disconnect and reconnect; ADSL big cat to die, to be restarted.
ADSL router broadband router and there is a large difference in performance in terms of the route. The reason for this phenomenon is on the hardware configuration. ADSL router CPU chip could be low-end network processors, such as: ARM7, etc., is only clocked at 50 Mhz, SDRAM memory is very small. Now mainstream broadband router, CPU clock speed as high as 100Mhz above, SDRAM memory 16M or more. There are also differences in processing capability on software functions, SESSION (session) is much less than the capacity broadband router. On the other, more advanced features, such as added more broadband router SPI firewall, DOS prevention, IP filtering and other security mechanisms as well as DHCP, DMZ, virtual server, DDNS function and so on, these ADSL MODEM simply do not have.
In certain size of network applications, using ADSL ROUTER for routing bite the bullet, limited performance and functionality, and should be used "more professional" broadband router. In addition to home, SOHO and other ultra-small network environment, the right ideas should be --ADSL ROUTER honestly do access in bridge mode, running routing and security mechanisms broadband router, and implement other special applications.
Summary: For the present, the main force of domestic broadband access, ADSL technology there are many line packages, and these packages are extended from a so-called two operating modes: bridging mode and routing mode. The two face mode, some users will know what to do, not knowing the kind of work mode selection. In fact, for domestic universal ADSL PPPoE virtual dial-up, these two modes can be used, but due to differences in scale network and which mode should be used better.
Overall: If families and small SOHO-type network, suggested routes operating mode; if Internet cafes, schools, businesses, communities and other large networking, bridging mode is recommended, along with the broadband router performs PPPoE dial-up and virtual routing capabilities .
Complement:
★ Modem ADSL bridging and routing modes difference
ADSL Modem into a bridge (enabled by default) and routing mode, when using a computer dial-up Internet, if not deliberately configure the ADSL routing, bridging function is actually used in the in this case the external network access to the IP PPPoE dial-up are to go directly to that computer, Modem only responsible for forwarding packets themselves from attack, which is why a machine to dial if you do not open the firewall will still be the reason external network attacks. When ADSL Modem is turned on after the routing function for external network access and IP attacks are directly loaded on Modem, then Modem is like a proxy server or firewall, internal machines to share Internet access via Modem are protected within the network, so multiple PC Modem via open Internet routing, basically shock wave patches do not fight, can from the Blaster virus attacks.
★ bridging and routing of image interpretation
process of transferring data over a network may be a metaphor in the following manner:
The data packet transmitted on the network, is now ready to send the goods from point A to point B compared to a box of goods.
The first step: the goods (packet) for packaging, to prevent theft of the road or falling apart (lost or monitor), in order to facilitate the packaging process B recipient easily unwrapped worldwide this method of packaging provisions (the agreement was born, we used TCP / IP is one such agreement), plus at a total of seven layers of wrapping paper (OSI 7-layer model).
Step two: Packaging finished, it is necessary for the transmission of goods, then there are two ways, one is a bridge, a routing. Bridging the equivalent of a section of the main road, the goods transferred by road to B; and the route is equivalent to a traffic policeman, he will tell which of the goods is recent, the fastest route to reach point B, it is to be placed at a critical crossroads necessary the router cargo routes command.
Third Step: When the goods arrive B, and the above-wrapping method according to the agreed (TCP / IP protocol) to unlock the packaging.
And routing bridge mode with respect to the mode of the link layer is. Bridge mode operation in the link layer, the network layer that is only over the transmission IP packet without any processing such as routing forwarding, packet filtering,, with respect to only one channel. Route mode works at the network layer, routing devices are generally the work of this layer above this level of rich content, the device can pppoe dial-up, firewall, there are nat function.
Equivalent to an ordinary switch bridge access, together with a connecting segment address or VLAN device. . Route, is connected to a different network segment. . Even do address translation.