A bureau uses s5500+s2300 Network Way, because the upstream light path resources are less, so in the Community adopt S2300 Cascade Way, Cascade uses 5 class twisted pair, the user uses the PPPOE Way to surf the internet. After opening, some two-level switch users reflect slow internet speed.
Process steps:
The first step, the test on the two-level corridor switch, found that there is a problem, open the local site is very slow. Ping the packet on the computer , found that the ping public network after the packet length of more than a large number of drops. Because the PING public network drops packet does not reflect the actual problem. the PING S5500 's gateway address was tested and the same problem was found. There is a problem locating the downstream port from the user side to the S5500 .
The second step, check the uplink port status of the level two switch, the port status is self-negotiation, the negotiated state is 100M full duplex. There are more CRC checksum errors on the upstream port . Because of the CRC check error, it can locate the fault and the physical layer correlation.
The third step, because there is no such problem on the first level switch and S5500 , all can be located in the first and two levels between the network cable, because the cable distance is longer, about 100m , and the field can not be replaced. Therefore consider can reduce the negotiation speed of the port to reduce the requirements of the network cable, try to force the port to 10M full-duplex settings, set after the ping packet is normal, but in the download when the ping packet and dropped packets.
Fourth step, the port mode is reduced to 10M half-duplex, at this time the download speed is normal, PING The package is normal, so that the location of the problem is 1 level to 2 switches between the network cable has problems, although you can negotiate to 100M Full duplex, but the line cannot actually support 100M full duplex.
PPPoE user's Internet speed slows due to network cable problems