Entering the target switch information

1. Locate the Switch Hostname/IP Address field in the left panel and enter in the IPv4 address (preferred) or the hostname of the switch.

2. Locate and enter the Community Name that the switch uses to communicate via SNMPv1/v2c (SNMP version is selectable in Setup). The community name is like a password.

Entering other required information

The switch will return information about the devices connected to its ports, but it returns only MAC addresses. We have to query other devices to obtain the IPv4 addresses associated with those MAC addresses by getting the ARP tables.

1. We can query two other devices via SNMPv1/v2c for their ARP tables. These ARP tables may contain the associations we are looking for. A good place to start is with a router. Enter the IPv4 or hostname, then the community name of one or two other devices. Leave the fields blank if you do not have other devices to query.

2. We recommend leaving 'Query Switch ARP Table' and 'Query Local ARP Table' checked because the switch or your computer may have the IP to MAC associations we are looking for. We also recommend leaving Enable Ping Sweep checked -- please verify the IP range in Setup and make sure that Query Local ARP Table is checked.

3. If you want the IP addresses resolved to hostnames, check the 'Resolve IPs to Hostnames' checkbox.

Running the switch query

Press Map Ports to begin the process. Once complete the Map Ports and Setup buttons will no longer be 'grayed out'. You can right click within the results grid to see additional options like printing.

Troubleshooting

• If you get no response from the switch, you will see no rows or columns populated in the grid and a timeout message will appear. Check to make sure the switch has SNMPv1/v2c enabled and verify that the community name you have for reading information from the switch is correct. If your switch has a permitted IP list, you may need to add your IP address to that list. Make sure your personal firewall is allowing UDP traffic on port 161 to travel BOTH ways.
• If you have a Dell switch and the MAC address/IP address/Hostname/Interface columns are blank, you probably have an older switch operating system that needs to be updated from Dell's support website.
• I get no IP addresses associated with the MAC addresses. You need to put a device like a file server or router (running SNMP) into the Primary or Secondary so you can access the device's ARP table. This table is required to map MAC addresses to IP addresses.