In the network of a carrier, the OptiX 2500+ equipment forms a backbone 2.5G ring. The OptiX 2500+ equipment is connected to the layer-3 switch and the 155M links of several sets of OptiX Metro 100 equipment. The outgoing data network port of the OptiX Metro 100 equipment is connected to the UA5000 equipment of the access network.
On day, a user complained that the network speed was too low to view web pages. The customer measured an actual 100 kbit/s network speed on the network port of the data interface board on the OptiX Metro 100 equipment. The standard network speed should be about 500 kbit/s.
1. According to the phenomenon, the fault is not caused by data configuration problems because the OptiX Metro 100 equipment obtains the IP address. Datacom personnel capture packets from the layer-3 switch. No virus attack is found but substantive broadcast packets exist. The port traffic reaches about 90 Mbit/s, obviously indicating the broadcast storm.
Work with the datacom and transmission personnel to isolate the VLAN.
Datacom personnel: Originate the super VLAN on the layer-3 switch. The super VLAN contains several sub-VLANs. Allocate one or several UA5000s to a sub-VLAN for transparent transmission setting.
Transmission personnel: Set the MAC port attribute of the data board on the OptiX 2500+ equipment to Tagware, modify the port to Access inside the data board, and configure the ID of the sub-VLAN for datacom equipment.
The possible causes are as follows:
1.Network broadcast storm
2.Virus attack such as the ARP
VLAN isolation can effectively reduce the effects of broadcast storms. For the networking mentioned in this case, it is recommended to perform VLAN isolation as soon as possible.