Friends, have you ever been in a situation where your network is slowly pausing, yet all switch ports are sending data continuously. You must have a feeling that the network Computer workException, and may even have suffered an attack. What are you going to do about it?
The author believes that the first step requires you to open the Network Protocol analyzer and capture the data sent from the core router. From the Protocol analyzer, you can see that a packet of IP addresses is flooding your network with immeasurable traffic. From its packet, you can get its MAC address. What are you going to do now? FindThe location of this computer.
You know, this computer must be connected to a port on the switch in the engine room. If we can point out which switch port a MAC address is on, you can confirm the computer, and either close the switch's port or go to its office to locate the computer directly, and then close it.
Here are some ways to help us find out which device is connected to one of the ports in the Cisco switch:
method One: Using a device called a port tracker
Here we would recommend a device PortTracker. PortTracker is an easy-to-use device that can help us design, validate, and audit computer networks. It is also a simple and effective way to check the switch and can ReportWhich network devices are connected to the port on the switch. It will map your network to you. This device can SolveThree questions: (1) unused port (PortTracker as a port waste) (2) reduced downtime and can know "what is connected to where" (3) identify the port at risk
PortTracker's Web site: http://www.porttracker.com/
method Two: Adopt the application software
There are a number of applications that can help us achieve this goal. Here are some of the software that I think is good:
Managed Switch Port Mapping: This software communicates with the switch using the SNMP protocol and can find out which device is connected to which port. It can collaborate with different brands of switches, displaying the allocation of VLANs and exporting them to spreadsheets. At present its PriceFor 199 dollars. However, you can download a 15-day trial version to see if it works. Its interface is shown below:
ManageEngine provides a switch port Mapper that helps administrators verify the ports that a device is connected to, eliminating the need for administrators to manually track network connections. This tool can foundDevices plugged into each port of a particular switch are useful for system and network engineers to understand the IP address, MAC address, and port effectiveness. Because this discovery is a real-time process, administrators can also view the status of the operation and the speed of each port. This tool can create a mapped image for the switch port and the device connected to it. The working interface of the following diagram:
Switchinspector: An Easy-to-use application that can help you design, validate, and audit your local area network. It provides an easy and efficient way to check a Cisco switch and report which network devices are connected to which port of the switch. Therefore, you do not need an administrator to manually track the network cable to see the connection between the port and the network device. In addition, it provides more granular information about your Cisco switches, which makes this tool a very valueof tools.
Lansurveyor:lansurveyor is able to automatically discover your network and generate a comprehensive network map that integrates the second and third layers of topology data (including switches to switches, switches to access nodes, switches to router ports). And this data can be imported by Microsoft Office Visio and easily shared with your colleagues.
Image below: Lansurveyor automatically generate network structure chart
The following figure: Lansurveyor automatic detection of network topology changes
Switchport Mapper: This tool is similar to Lansurveyor, it can also remotely detect devices connected to each port on the switch, and has the ability to identify hosts based on MAC address, IP address, host name, etc.
Of course, the author's recommended tool does not include FreeOpen Source Tool products. Readers can look for themselves.
Method Three: Using Cisco's iOS CLI command
In fact, the way to see which MAC address is connected to which port of the switch is to use the show mac-address-table command. For example:
switch# Show Mac-address-table
Mac Address Table
——————————————-
Vlan Mac Address Type Ports
.....................................................................
1 0007.e9e2.2d7d DYNAMIC FA0/5
1 0009.0f30.07e9 DYNAMIC FA0/48
1 0009.5bbc.af04 DYNAMIC Fa0/28
1 00e0.bb2c.30d1 DYNAMIC GI0/1
1 00e0.bb2c.3e5f DYNAMIC GI0/1
Total Mac Addresses for this Criterion:5
switch#
(in order to save space, we have deleted this form)
With this command, you can find out which MAC address is connected to which port on the switch. But you have to go to each switch and run this command. If the network has stopped, you will have to go to the console of each switch. But if you have one of these tools, you can easily draw a network map of which MAC address is connected to which switch, which saves you a lot of trouble.
Conclusion
When your network is at risk, it is important to know which device is connected to which port of the switch. But if you run to the network room, find the console cable, "Follow up", and then track, find the port from the switch to the wall, no trouble! If you plan ahead, prepare the application software and port mapping tool for network analysis in advance, when the problem is just sprouting, QuickTo determine the location of the failure.
