Common Enterprise router faults and troubleshooting methods

I. Hardware problems

Vro hardware mainly includes memory, power supply, transmission media (that is, cables), CSU/DSU, supplier media, CPU, interfaces, modules, etc, if the purchased vro is of reliable quality, the probability of hardware problems is relatively low. However, hardware faults often occur and can only be delivered for repair. There are three common hardware faults.

1. The system cannot be powered on normally.

Fault description: when the power switch of the router is enabled, the Power Light on the router's front panel is not on, and the fan is not turned.

Fault cause: the most suspicious objects are power supplies and cables.

Solution: In this situation, the most suspicious is the power supply system, so the first thing to check is the power supply system to see if the power outlet has current and the voltage is normal. If the power supply is normal, check whether the power cord is damaged or not. If the power cord is damaged, replace it. If the power cord is loose, plug it again. If the problem is solved, it will be easy to solve, but if the problem persists, the suspect object should be transferred to the power supply of the router. Next, check the power supply insurance of the router, if it is burned, the problem should be solved after replacement. If the situation does not improve, the enterprise's Broadband Router should be sent to a special place for repair, after all, hardware problems cannot be solved by yourself, especially products that are still under warranty.

2. Damaged parts

Fault description: When a part is inserted into a vro, other parts of the enterprise network system can work normally, but cannot correctly identify the inserted part; or, the inserted parts can be correctly identified, but after the correct configuration, the interface will not work properly.

Fault cause: the former is most likely due to a problem with the inserted part or the interface card failure, while the latter is mostly due to other physical faults on the router.

Solution: if the problem is the previous one, replace the component with the same model with the one that cannot be correctly identified and insert it to the router. If the problem can be identified correctly, the problem must be on the plug-in part. If it cannot be identified, try another interface to identify it, the problem lies in the previous interface. In the latter case, most of the problems are caused by a component in the vro, so the solution can only be sent for repair.

3. Poor router cooling or incompatible Devices

Fault: the Internet connection is normal, but after a period of time, the network speed begins to drop, or even frequent disconnection.

Fault cause: the router may have poor performance and stability, or the network may be interrupted due to the high temperature of the router, ADSLModem, optical fiber access device, and other equipment, it is also possible that the vro model is not compatible with the local device of the ISP (Network supplier), but most of the reasons are caused by improper configuration of the vro (this is not much to be analyzed here, for further details ).

Solution: when the network speed drops, you can feel the surface temperature of the router and other network access equipment. If you feel very hot, it indicates that the frequent disconnection is caused by hardware equipment problems, it is best to consider changing a new device, and the Internet will be normal. You can also place the routers and so on in a place with better heat dissipation conditions, and the situation will improve. If the temperature of the device is normal, it is likely that the router is incompatible with the local device of the ISP. If the device is out of line due to incompatibility, the solution is to replace another vro.

Ii. Software System Problems

With the emergence of new products and the increasing demand for Internet and LAN bandwidth, the software system of enterprise broadband routers is also evolving, because different versions of software systems support different feature sets and different routers have different software systems, when the functions and performance required by the software are different, there will be a series of faults.

1. Some functions of Enterprise broadband routers cannot be implemented

Fault description: The router configuration is correct, but some functions cannot be implemented.

Cause of failure: If the router configuration is correct, the problem should be on the software system of the router.

Solution: Upgrade the software system. Because the system software of a vro usually has many versions and each version supports different functions, the biggest possible cause of this situation is that the current software system version does not support some features, leading to the loss of some vro functions. Therefore, you can solve the problem without unexpected software upgrades. This type of problem has a great impact on enterprise users, but it is easily overlooked by enterprise network administrators, because enterprise users who frequently use the network need a lot of functions, if one or two of them are missing, it will bring a lot of unnecessary trouble to enterprise users.

2. Unable to upgrade System Software

Fault description: the upgrade process cannot be completed when the system software is upgraded, and it is forced to stop at a certain stage.

Cause of failure: this situation is mostly caused by insufficient capacity of NVRAM (an electrically erasable memory that is usually used to store system software.

Solution: since the content of the software to be upgraded exceeds the capacity of NVRAM, it is necessary to upgrade NVRAM, which not only expands the capacity of NVRAM, you can also update the data.

Iii. configuration problems

The most common problem is that the router fails due to misconfiguration. That is, the network cannot run properly due to the improper configuration of the router, for example, the router parameters at both ends of the line do not match, the parameters are incorrect, or the routing mask is set incorrectly. Configuration errors are very complicated. faults come from many aspects. Typical vro configuration files can be divided into the following parts: the Administrator part (vro name, password, service, log ); port (address, encapsulation, bandwidth, measurement overhead, authentication); routing protocol (IGRP/VPN, OSPF, RIP, and BGP ); traffic Management (Access Control List, group), routing principles (route ing), access outside the bandwidth (console, remote logon, dial-up), etc., that is, most of the configuration problems of Enterprise broadband routers come from the configuration in the above files.

1. Unable to dial

Fault description: normal dialing procedures cannot be performed.

Fault cause: the main problem lies in the router address settings.

Solution: the solution is simple. Open a Web browser and enter the management address of the router in the address bar, for example, 192.168.1.1, at this time, the system will require you to enter the login password (the password can be found in the product manual), log on to the management interface, and select the WAN port setting option under "Network Parameters, in the main window on the right, select "PPPoE" for "WAN port connection type", enter "Internet account" and "Internet password", and click "Connect.

2. Some computers cannot be connected normally.

Fault description: there is no problem with the vro hardware, and the connected computer is no problem, but normal connection cannot be achieved, while other computers in the LAN can connect to the Internet normally.

Cause of failure: This is generally because the ISP is bound to a MAC address and cannot be connected, because some ISPs have bound the MAC address on the authentication server to limit the number of connected users, users that are not within the bound range cannot connect to the Internet.

Solution: First connect the computer bound with the MAC address to the LAN port of the router (but the router should not connect to the Modem or the wiring provided by the ISP), and then use the clone function of the MAC address of the router, copy the MAC address of the network adapter to the WAN port of the Broadband Router, and then perform the following operations on the unbound COMPUTER: Start → run under Windows2000/XP ", enter "cmd/kipconfig/all". "PhysicalAddress" indicates the MAC address of the local machine.

3. Frequent network disconnection

Fault description: When a vro is opened, the network runs normally. However, after accessing the internet for a period of time, the vro is often dropped. After the vro is closed, the network can be restarted and connected again.

Fault cause: the cause of the fault is complicated. It may be due to hardware problems (I have already introduced it here and I will not talk about it here ), it is also possible that some people often use the btsoftware to download data in the LAN, which seriously affects the network speed and leads to low network performance. However, most of the cases are caused by improper settings, which are divided into the following situations:

(1) BT downloading slows down the network speed, leading to disconnection. In a shared network, BT downloading is a major problem that affects the network speed. Therefore, in the case of frequent online disconnection, you should first check whether someone on the LAN frequently uses the btsoftware to download data, the improper use was ruled out to continue looking for the root cause.

Solution: Disable BT and restart the router.

(2) ip address confusion caused by Multiple DHCP servers. When Multiple DHCP servers exist on the network, IP addresses in the Network may conflict, resulting in frequent and irregular disconnection.

Solution: Disable all DHCP servers in the network and manually specify the IP address.

(3) The Connection Mode settings are incorrect.

Solution: On the vro Management page, select "WAN Port Settings" in "Network Parameters" in the left-side menu. Select the "On-Demand connection" option in "corresponding connection mode" and set "automatic disconnection wait time" to "0 minutes", the router will not be automatically disconnected.

(4) suffering from Trojan attacks. This is another important reason for frequent network disconnection in addition to incorrect settings.

Solution: If you suspect that you have been attacked by a hacker Trojan, first check whether all connected computers are infected with viruses or Trojans and use genuine anti-virus software or Trojan killing tools, scan to clear viruses or Trojans from your computer and then access the internet.

4. Unable to browse the webpage

Fault: The webpage cannot be opened normally, but programs like QQ can run normally.

Cause of failure: This is a DNS resolution problem on the vro。. If the gateway is set to a DNS address, which is DNSProxy and is not a real DNS address, it may cause an address resolution error.

Solution: To solve this problem, we recommend that you manually set the DNS server address (the address provided by the ISP terminal) on the router and computer Nic to open the router setting interface, find the "WAN port Parameters" field in "Network Parameters", and then manually set the DNS server address below. In addition, in the "DHCP service" setting item, you also need to manually set the DNS server address and the backup DNS server address, which needs to be obtained from the ISP supplier.

5. Unable to log on to the vro Management page

Fault description: I want to configure shared Internet access for the enterprise's Broadband Router, but cannot enter the management interface.

Fault cause: the connection created during the previous login is incorrect.

Solution: If you have logged on to the router management interface before, you should first check the hardware connection between the Broadband Router and the computer, and check whether the indicators on the LAN port of the router are normal, if firewall or real-time monitoring anti-virus software is installed on the computer, disable it temporarily, set the local IP address to the same network segment as the Broadband Router, and then set the gateway address as the default IP address of the router. Generally, the Broadband Router provides a Web management mode. Therefore, open the "Internet Options" dialog box and select "Never dial-up connections" in the "connection" option, click "LAN Settings" and deselect all selected options.

6. Forget the logon password on the vro Management page.

Solution: a Reset button is usually displayed on the rear panel of the vro. Press this button for several seconds to restore the default factory configuration of the vro. the username and password on the logon Management page are restored to the initial values respectively, follow the instructions in the vro User Manual to log on.

Summary: Although there are many kinds of faults that may occur in the use of the Broadband Router in the enterprise network, the causes are also different, but as long as you need to analyze some common fault phenomena, combined with experience, the problem can be solved through continuous practice in practical work.