SNMP

SNMP – Simple Network Management Protocol

SNMP – In a simplified manner, is an Internet standard protocol for managing devices in IP networks.

Devices that typically support SNMP include routers, switches, IP phones, printers, racks, and other devices that have this functionality.

The SmartCenter SNMP Plugin collects information from each previously registered device and displays it in the Menu > Inventory > SNMP.
It allows users to view the information provided by each device, which can be exported to an XLSX file.

The Almaden SNMP is a plugin that runs on a Windows operating system server with the pre-installed (Almaden) Automatos Server Agent. It enables monitoring services for devices with a standard SNMP agent installed. The machine on which the plugin is installed functions as a “monitoring center” that stays in contact with the monitored devices on the network every minute.

Although this plugin can only be installed on Windows platforms, it can enable monitoring for any device on the network as long as it has an SNMP agent installed and properly configured

1. Installation prerequisites:

• Server with Windows 2008 or higher operating system and the (Almaden) Automatos Server Agent pre-installed.
• This machine, responsible for device monitoring, must remain continuously powered on to collect data throughout the day.
• SNMP agent must be installed and enabled on the devices to be monitored by this plugin.
• The IP address of the host where the plugin is installed must be included in the range of allowed IP addresses to read the device’s status.
• The SNMP agent must be configured to send traps to the IP address of the host where the plugin is installed and to the “trap-listening” port.
• The default port for “trap-listening” is 162. If this port cannot be used for this purpose, it will be necessary to configure the plugin to use another port. This operation will be further explained in section 3.

2. Installation Procedures:

• The Almaden SNMP plugin is distributed as an executable file. Run it to start the installation process and follow the instructions provided in the subsequent windows.
• In the License Agreement window, select “I agree” if you agree with the terms of service, then click “Yes.” If not, click “No” to exit the installation.
• If you have agreed to the terms of service and clicked “Yes” in the previous window, click “Finish.”
• After completing the plugin installation, you will need to choose the devices on the network that will be monitored. This procedure is described in the next section.

3. Choosing the network devices to monitor:

After successfully installing the plugin, you need to select the devices to be monitored. You can either enter specific IP addresses to monitor or discover which IP addresses can be found by the plugin on the network. To choose the devices, follow the steps described below:

• Open the ASA Control Center (ASA’s graphical interface).
• Click on “Configuration” in the top menu of the window, and then choose “Agent.”
• In the “Agent Configuration” window, select the “Plugins” tab, and double-click on “SNMP config.” The “SNMP Plugin Configuration” window will appear.
• If you want to enable monitoring services for a specific device, click on the “Add” button. If you want to discover which devices can be monitored within your network or within a certain range of IP addresses, click on the “Discovery” button.

4. Configuring the Device to be Monitored:

• Click on the “Add” button in the “SNMP Plugin Configuration” window to open the “Device Configuration” window. In the “Device Configuration”
• window, enter a Community Name for reading access if you are using one. The Community Name is used to send SNMP traps to another device. It functions like a password that grants access to the statistics of a router or other device. If the Community Name is valid, the device will respond with the requested information; otherwise, the device will not respond. Ensure that the provided Community Name is the same as configured on the devices.

• The “Port number” field shows which port the device is using. The “Response Timeout” field sets the maximum time that the plugin will wait for a response to the sent request before displaying a timeout error message.
• In the “IP address” field, enter the IP address of the device you wish to monitor, and check the “Auto configure” option; this option will automatically check the SNMP agent version installed on the host.
• In the “Max errors” field, you can set a maximum number of errors, the maximum waiting time in seconds for the next attempt, which you set in the “Delay(s)” field, and the number of retries you set in the “Retries” field. These fields work together.
• Click the “Test” button at the bottom of the window. If the device successfully responds to the contact test, the “Status” field at the bottom of the window will turn green, and a “Success” message will appear shortly after. Otherwise, an error message will appear. Refer to the “Troubleshooting” section in this procedure for suggestions on resolving errors.
• After successfully testing the device, click the “Ok” button to include it in the list of devices to be monitored. Repeat the steps for each individual device you want to monitor.
• If you clicked on the “Discovery” button in the “SNMP Plugin Configuration” window, the “Auto Discover SNMP Devices” window will open. In the “How to scan” panel, choose:

• “Ping, port and SNMP scan” for the plugin to send a ping to each address within the specified range and, upon receiving a response, check if the defined port is available (Listening). If the port is available, the plugin will send an SNMP information request and wait for a response from the devices. If successful, the device(s) will be listed in green; otherwise, they will be listed in red.
• “SNMP direct scan” to directly perform data discovery (via SNMP) on each IP address within the defined range.
• “SNMP broadcast scan” to perform a data discovery on a broadcast address. Using this option, the plugin broadcasts on the network (sending packets to all available machines within that range of IP addresses) and checks which machines respond to the packet. In the “What to scan” panel, choose:

• “Scan my subnet(s)” to look for devices to monitor on your network. This choice is the default.
• “Scan an address range” to look for devices within a range of IP addresses. In this option, you enter the “Start” field where the IP address range begins and the “End” field where it ends. You cannot choose a range containing more than 1024 IP addresses; if needed, execute separate searches covering up to 1024 IP addresses per search.
• If you are using a Community Name to authorize read access, enter it in the “Read Community Name” field. Keep in mind that the provided Community Name will be used to try to access all SNMP agents within the specified range. Therefore, if you have IP ranges with different Community Names, you will have to perform separate searches for each Community Name.
• After configuring all the filters and desired options, click the “Start” button to execute the search. Shortly after, all devices currently responding to SNMP contact within the desired search range will be displayed in the box below. Devices marked with a green button in the “Address” column are successfully responding with all SNMP status data required for Almaden monitoring services. Devices marked with a red button are not responding with status data. These devices cannot be subjected to monitoring services. Refer to the “Troubleshooting” section in this procedure for suggestions on resolving this situation.

• Click “OK” to return to the “SNMP Plugin Configuration” window and choose the “Traps” tab. In this tab, you can configure the designation of the “trap-listening” port. The plugin uses the default port 162. Change this port in the “Port number” field if it cannot be used. If the plugin host has multiple IP addresses, you must designate this port for a single IP address by selecting it in the “Bind to address” field.
• Click the “OK” button at the bottom of the “SNMP Plugin Configuration” window, then the “OK” button in the “Agent Configuration” window, and restart the ASA service for monitoring to begin shortly after.

5. Alerts:

• For security reasons, it is recommended that you restrict the IP address ranges allowed to send read/write commands to the SNMP agent. You should include the IP address of the plugin’s host within the allowed range of addresses to read the devices’ status.

• If there is a machine with two network cards (interfaces), only one should be selected in the Discovery (SNMP Plugin Configuration). This will retrieve information from both interfaces. To prevent errors, in the plugin configuration where there is the “Discovery” option under “How to Scan,” enable the “No duplicate SysName” option. This will filter the result, and only one interface will be displayed for machines with more than one interface.

6. Troubleshooting:

If you encounter an error message or see a red button while trying to add devices to be monitored in the “Auto Discover SNMP Devices” window (using the “Discovery” button) or the “Device Configuration” window (using the “Add” button), check the items listed below to attempt to resolve the issue:

• Check if the device to be monitored is powered on and connected to the network.
• Confirm if the SNMP agent is indeed installed, active, and properly configured on the device to be monitored.
• Verify if the network segment between the computer where the plugin is installed and the device to be monitored is operating correctly. Try to contact the monitored device through the computer where the plugin is installed. If you notice that the connection is slow, try using a longer expiration time to make contact with the device, based on the response time reported by the “ping” operation. You can increase the timeout time for the contact attempt by entering a value greater than 100 ms (the default value) in the “Response Timeout” field in the configuration window.
• Confirm if the IP address of the computer where the plugin is installed is included in the range of IP addresses allowed to read the devices’ status.
• Ensure that the Read Community Name entered in the “Community Name” field is the same as configured in the SNMP agent. If you haven’t changed the “Community Name” field, the plugin will attempt to contact the SNMP agent using the default value “public.”
• If you did not check the “Auto-configure” option in the “Device Configuration” window, try contacting the device by choosing a different SNMP version (SNMP v1 or SNMP v2c) or check the “Auto-configure” option.
• Check which port the SNMP agent is configured to receive SNMP queries. The default port used by the plugin is 161. You can set the plugin to use another port by entering its number in the “Port” field in both the “Auto Discover SNMP Devices” window (using the “Discovery” button) and the “Device Configuration” window (using the “Add” button).