...

An SNMP health monitor sends an SNMPv1, SNMPv2c, or SNMPv3 request to the monitored server. The SNMP agent in the managed server provides the data in the form of variables, and each variable is associated with an unique OID (object identifier). An OID is a dotted-decimal number that defines the location of the object in the universal MIB tree. You can manually enter up to 15 OIDs to be monitored by the SNMP monitor. The server is considered available if the response received from the server matches the expected result for all OIDs. If the server does not respond after a specified number of requests, the server is declared down by the monitor.
Image Removed
NIOS 8.1NIOS Administrator Guide (Rev. A) 1057
Managing DNS Traffic Control
To configure an SNMP OID health monitor, complete the following:

1. From the Data Management tab, select the DNS tab -> Traffic Control tab, and then click Manage Health Monitors in the Toolbar.
2. In the Health Monitors Manager, click the arrow next to the Add icon and select SNMP Health Monitor.
3. In the SNMP Health Monitor Wizard, complete the following:
   • Name: Enter a name for the SNMP monitor.
   • Interval (seconds): Enter the interval value in seconds. The health monitor runs only for the specified interval and it is measured from the end of the previous monitor cycle. The default value is five.
   • Timeout (seconds): Enter the timeout value in seconds. The monitor waits for the number of seconds that you specify after sending a response. If it does not receive a response within the number of seconds that you specify, then the appliance considers this check failed. The monitor discards any responses it receives after the timeout. The default value is 15.

   • Retry Up Count: Enter a retry up count. When you specify a value, the appliance checks whether the server is up based on the following:

     interval*retry up count

     . For example, if you specify the interval as five seconds and the retry up count as 10, then the appliance tries to connect to the server every five seconds for a period of 50 seconds. If the server is down initially, the appliance tries to connect to the server for 50 seconds in sequence. When the connection is successful, the SNMP monitor considers the server to be up. If the server is unavailable for an entire period of 50 seconds, the appliance considers this connection as a failure.

   • Retry Down Count: Enter a retry down count. The SNMP monitor considers the server unavailable only if the server is unavailable during the period:

     interval*retry down count

     . For example, if you specify the interval as five seconds and the retry down count as 10, then the appliance checks if the server is unavailable for 50 seconds in sequence. If the server is unavailable for an entire period of 50 seconds, the appliance considers the server to be down.

   • Port: Specify a port for the SNMP connection. The appliance displays 161 by default. You can specify a value between zero and 65535.
   • Comment: Enter information about the SNMP health monitor.
4. Click Next and complete the following:
   • Version: Select the SNMP version, v1, v2c, or v3. Note that the available options for versions v1 and v2c differ from those for v3 version.
   • (SNMPv1 and SNMPv2c only) Community: Enter the text string that the SNMP monitor must send along with the queries to the server for authentication. The community string is similar to a password and the server accepts queries only from the SNMP monitor that provide the correct community string. Note that this community string must match exactly what you enter in the management system. The default value is public.
   • (SNMPv3 only) SNMPv3User: Click Select or Create to specify an SNMPv3 user. For information about SNMPv3 users, see Configuring SNMPv3 Users.
     If you are modifying an already existing SNMPv3 health monitor in the SNMP Health Monitor editor, two additional optional fields become available:
     • Context: enter an arbitrary string.
     • EngineID: enter an arbitrary string that can contain from 10 to 64 hexadecimal digits (5 to 32 octet numbers).
   Click the Add icon above the Health Monitor SNMP OIDs table to add an SNMP OID entry. Complete the following:

• • OID: Specify the object identifier. An OID is a unique dotted-decimal number that identifies the location of the object in the MIB tree. For more information about OIDs, see SNMP MIB Hierarchy.
  • Type: Select either String or Integer from the drop-down list.
  • Operator: Select one of these operators from the drop-down list: Any, Equals, Larger or equals, Range, and Smaller or equals.

...

...

• • Value: If the operator is Equals, Larger or equals, or Smaller or equals, enter a value. If the operator is Range, enter the minimum and maximum values in the Min value and Max value fields respectively.
  • Comment: Enter information about the SNMP OID entry.
  • Click Add to add the SNMP OID to the table.

5. Click Next to add extensible attributes. For information, see Using Extensible Attributes .

6. To schedule the change, click Next or Schedule for Later. In the Schedule Change panel, select Now to immediately execute this task. Or select Later to schedule this task, and then specify a date, time, and time zone.

7. Save the configuration.

Anchor
Configuring TCP Health Monitors Configuring TCP Health Monitors

Anchor
bookmark2111 bookmark2111

Configuring TCP Health Monitors

...

1. From the Data Management tab, select the DNS tab -> Traffic Control tab, and then click Manage Health Monitors in the Toolbar.
2. In the Health Monitors Manager, click the arrow next to the Add icon and select TCP Health Monitor.
3. In the TCP Health Monitor Wizard, complete the following:
   • Name: Enter a name for the TCP health monitor.
   • Interval (seconds): Enter the interval value in seconds. The health monitor runs only for the specified interval and it is measured from the end of the previous monitor cycle. The default value is five.
   • Timeout (seconds): Enter the timeout value in seconds. The monitor waits for the number of seconds that you specify after sending a response. If it does not receive a response within the number of seconds that you specify, then the appliance considers this check as failed. The monitor discards any response it receives after the timeout. The default value is 15.

   • Retry Up Count: Enter a retry up count. When you specify a value, the appliance checks whether the server is up based on the following:

     interval*retry up count

     . For example, if you specify the interval as five seconds and the retry up count as 10 seconds, then the appliance tries to connect to the server every five seconds for a period of 50 seconds. If the server is down initially, the appliance tries to connect to the server for 50 seconds in sequence. When the connection is successful, the TCP monitor considers the server to be up. If the server is unavailable for an entire period of 50 seconds, the appliance considers this connection as a failure.

   • Retry Down Count: Enter a retry down count. The TCP monitor considers the server unavailable only if the server is unavailable during the period:

     interval*retry down count

     . For example, if you specify the interval as five seconds and the retry down count as 10 seconds, then the appliance checks if the server is unavailable for 50 seconds in sequence. If the server is unavailable for an entire period of 50 seconds, the appliance considers the server to be down.

   • Port: Specify a port for TCP connection. You can specify a value between zero and 65535.
   • Comment: Enter information about the TCP health monitor.
4. Click Next to add extensible attributes. For information, see Using Extensible Attributes .
5. To schedule the change, click Next or Schedule for Later. In the Schedule Change panel, select Now to immediately execute this task. Or select Later to schedule this task, and then specify a date, time, and time zone.
6. Save the configuration.

...

You can upload multiple certificates to the appliance and associate them with HTTP and SIP health monitors. The appliance supports certificates that are in PEM or PKCS#12 format only. A PEM file can contain more than one certificate. Note that the uploaded certificate must include both the client certificate and the private key. You can add, delete or view certificates.
Image Removed
NIOS 8.1NIOS Administrator Guide (Rev. A) 1059
Managing DNS Traffic Control
To upload a health monitor certificate:

...

To upload a health monitor certificate:

1. From the Data Management tab, select the DNS tab -> Traffic Control tab, and then click Manage Health Monitors in the Toolbar.
2. In the Health Monitors Manager, click the Manage Health Monitor Certificates icon.
3. In the Health Monitor Certificates window, click the Add icon.
4. In the Upload window, click Select and navigate to the certificate you want to upload.
5. Select the file and click Upload.

...

• Issuer: The name of the trusted CA that issued the certificate.
• Valid From: The date from which the certificate becomes valid.
• Valid To: The date until which the certificate is valid.
• Subject: The name of the certificate.

To upload a certificate from a web browser:

1. Export a PEM file from a web browser.
2. Generate a private key using the following command:

— openssl req -x509 -nodes -days 365 -newkey rsa:1024 -keyout mycert.pem -out mycert.pem

     3. Copy the private key section out of mycert.pem and add it to the PEM file from the web browser.

     4. Or add both the PEM and the private key together as PKCS#12.

You can also do the following in the Health Monitor Certificates window:

...

1. From the Data Management tab, select the DNS tab -> Traffic Control tab, and then click Manage Health Monitors in the Toolbar.
2. In the Health Monitors Manager, click the Action icon Image Removed icon Image Added next to the health monitor name, and select Edit from the menu.
3. The Health Monitor editor contains the following tabs from which you can modify data:
   • General: This tab displays the health monitor Name, Comment, Interval, Timeout, Retry Up Count, and Retry Down Count fields. You can edit the values.
   • (HTTP, SIP, and SNMP health monitors) Protocol: This tab displays the protocol data that you can modify.
   • (HTTP/S health monitors only) Request/Response: This tab displays HTTP request and response check options for HTTP/S health monitors.
   • Extensible Attributes: Add and delete extensible attributes that are associated with the pool. You can also modify the values of extensible attributes. For information, see Using Extensible Attributes.

For information about modifying the details of specific monitors, see the corresponding sections above.

4. To schedule this task, click the Schedule icon at the top of the wizard. In the Schedule Change panel, select Later and enter a date, time, and time zone. The Schedule icon is green when there is a pending scheduled task. For information, see Scheduling Tasks.

5. Save the configuration.

...

Anchor
Viewing Health Monitors Viewing Health Monitors

Anchor
bookmark2114 bookmark2114

Viewing Health Monitors

...

1. From the Data Management tab, select the DNS tab -> Traffic Control tab, and then click Manage Health Monitors in the Toolbar.
2. The Health Monitors Manager displays the following information:
   • Name: The name of the health monitor.
   • Type: The type of health monitor.
   • Comment: Displays information about the health monitor.
   • Interval: The interval value in seconds.
   • Timeout: The timeout value in seconds.
   • Retry Up Count: The retry up count specified for the respective health monitor.
   • Retry Down Count: The retry down count specified for the respective health monitor.
   • Port: The port number specified for the respective health monitor. Note that this is not valid for an ICMP monitor.
   • Site: Value that was entered for the respective health monitor.

You can do the following in the Health Monitors Manager:

• Define new health monitors. For more information, see the following sections:
  • Configuring HTTP Health Monitors
  • Configuring ICMP Health Monitors
  • Configuring PDP Health Monitors
  • Configuring SIP Health Monitors
  • Configuring SNMP Health Monitors
  • Configuring TCP Health Monitors
• Edit existing health monitors. For more information, see Modifying Health Monitors.
• Manage health monitor certificates. For more information, see Managing Health Monitor Certificates on page 1059.
• Delete existing health monitors. For more information, see Deleting Health Monitors.
• Click the Export icon to export the list of monitors to a .csv file.
• Click the Print icon to print the list of monitors.
• Use filters and the Go to function to narrow down the list. With the autocomplete feature, you can just enter the first few characters of an object name in the Go to field and select the monitor from the possible matches. Create a quick filter to save frequently used filter criteria. For information, see Using Quick Filters.

...

1. From the Data Management tab, select the DNS tab -> Traffic Control tab, and then click Manage Health Monitors in the Toolbar.
2. In the Health Monitors Manager, click the Action icon Image Removed icon Image Added next to the health monitor name and select Delete from the menu.
3. In the Delete Confirmation dialog box, click Yes to delete or No to cancel.

Click Schedule Deletion and in the Schedule Change panel, enter a date, time, and time zone to schedule deletion at a later date and time. For more information, see Scheduling Deletions.

...