The problem of the router's external network port shutdown due to excessive traffic

Using a unit of Cisco router, leased telecom 30MB to do local access and 10MB Education Network dual-line broadband connection, the network has been running stably, the router also works properly. However, after the increase in the number of network users, telecom 30MB can not meet the needs, leased telecom 1OOMB to solve the bandwidth bottleneck.

Routing Run Environment

Using a unit of Cisco router, leased telecom 30MB to do local access and 10MB Education Network dual-line broadband connection, the network has been running stably, the router also works properly. However, after the increase in the number of network users, telecom 30MB can not meet the needs, leased telecom 1OOMB to solve the bandwidth bottleneck.

Telecommunications using optical fiber access to the unit computer room, the use of hundred trillion photoelectric converter after conversion through the twisted pair of cables to the router extranet port, the router is using Gigabit port as an external network, because the photoelectric converter only 1O0MB, the port after the speed display 100MB.

Receive Errors "External network port traffic is zero

After the increase in broadband, the administrator in the running process found that every day when the router outside the network traffic exceeded 50MBPS/S, the port will appear "receive Errors", traffic is very large error, a lot of error information. With the advent of the Web page can not open, unable to connect to the external network failure, telnet to the router above, found that the corresponding external network of telecommunications no traffic, the display status of up, the other ports on the router work properly. The first reflection is the telecommunications side of the problem, is the telephone to inform the telecommunications over there, the other side quickly replied that there is no problem, and asked whether the photoelectric converter crashed.

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Then the administrator will reset the photoelectric conversion, the failure can not be ruled out. In the absence of a solution, we have to restart the router, troubleshooting. After less than one hours, the fault reappeared. After telnet to the router to perform the shutdown and undo shutdown, troubleshoot the external network port. Apply all security policies about the virus to this port, modify the TCP MSS to 2048 (vendor default 1460), and the failure occurs frequently.

Fault analysis of Router external network port shutdown

In the event of a failure, the CPU display 23%,memory is 33%, the normal state, and other interfaces are working properly, it seems that the problem still appears on the port above. This port has been in use for two years, upgrade expansion before the port does not appear normal communication, port hardware should be what the problem.

Through the network management software to the port before the closure of the flow detection, found that the port before the closure of a large flow through (over 80mbps/s), the display port error message is also more.

Through the analysis that should be the network traffic is too large, the utilization rate caused by too high. Traffic over 80%, resulting in the port can not be normal, resulting in the inability to connect to the extranet, the Web page can not open the fault. If the port works in Gigabit mode, the 100MB bandwidth uses only that port 10%, so the port can be handled easily.

Router External network port shutdown solution

After finding the cause of the problem, the recommended solution is to purchase a gigabit photoelectric converter instead of the original hundred devices, the cost is low. However, in order to ensure the stability of the network operation, the purchase of a gigabit-port routing module, the direct use of optical fiber communication, reduce network latency.

Telecommunications is controlled by the port speed limit to ensure the provision of hundred gigabit bandwidth. Run through a period of time, found that the port in addition to a small number of error messages, no longer have the port shutdown without reason. Network traffic is too large to cause the router extranet port shutdown troubleshooting.