Finding duplicate IPs
One of the most annoying problems in IP networks is duplicate IP addresses. The funny thing is that if you are familiar with the problem, what causes it, and how to find it, it becomes one of the most simple ones to solve.
Getting ready
When you suspect a duplicate address in the network, the first thing to do will be to use the simple CLI commands—ARP and Ping. If you don't locate the problem, connect Wireshark to the switch and in a large network to every VLAN in the network and move step-by-step until you find the problem.
How to do it...
We start with the phenomena, such as slow access to a server or to another device, slow access to the Internet, and all the pings that you don't get replies to.
When you get slow access to a network device, one of the problems that might arise is that the IP address of this device collides with another address. To verify this, ping the IP address.
Tip
In some devices, when their address collides with an identical address, the driver will...