Servicenow - F5 Load Balancers Discovery Step-by-Step Guide

Sohail Khilji · ‎04-03-2024

How to Discover F5 Load Balancers Step-by-Step Guide in Servicenow

Lets see how F5 BIG-IP loadbalancers get discovered in servicenow using Discovery in a step by step guide.

Quick Summary:

To discover F5 BIG-IP load balancers in ServiceNow using SNMP, first configure SNMP credentials and ensure port 161 is open between the MID Server and F5 devices. Then, define a discovery schedule specifying the configuration item, MID Server, and IP addresses or subnets of the F5 devices. Run the discovery process and monitor its progress. If issues arise, debug by testing credentials and port connectivity, and resolve any network or credential issues. Additionally, if discovery fails or encounters classification issues, add SNMP OIDs for F5 devices and rerun discovery. By following these steps, you can efficiently discover and integrate F5 load balancers into your ServiceNow CMDB.

Requirements : So What do we need ? (To discover F5 you would need the below requirements to get started for SNMP, it can also be discoverd via REST - which i may post later...)

> F5 IP addresses to discovery. { in my case we will }

> Port 161 needs to be opened from MID server to destination F5.

> SNMP Credentials

> To successfully discover the load balancer pool members, set the 'sys_db_bigpipe.displayservicenamesof' the load balancer to false.

> For more detailed Requirements Click here

For F5 cluster discovery

The horizontal discovery process can find F5 clusters. To discover clusters, the credentials must have read permission to traffic groups. For SNMP, this is the regular read permission. For SSH, you need to have Traffic Management Shell (TMSH shell) enabled and accessible.

Note : add tmsh shell to mid server property...

Now we have everyting in place to get started....

Step1: Configure SNMP Credentails >

Aquire this credentails from the consern team and click on ''Test Credentails'' to verify it

Provide credentials a name, username, password , encryption infos, mid server on which the discovery will connect to F5. (if required create a credentails alias, i usually do it save multiple creds check...)

Step2: Port Opening >

Request the Network/Firewall team to open 161 UDP port From your mid server IP to the target F5 device which your discovering. (ensure if the traffic is open before proceeding to save same...)

Step3: Configure Discovery Schedule >

As like i have created a discovery schedule above you can create a schedule for F5 discovery.

a. Provide a sensible name.

b. Discover : choose 'configuration item'.

c. Mid server selection : you can select 'specific mid server' open of like me you can create a discovery behaviour by selecting use behaviour.

(I created a 'SNMP Only' behaviour for one of my mid server as like below and selected it on 'Behaviour' field)

d. select location.

e. set the run scheduled as needed.

f. Create 'Credential alias' if needed to use specific creds for this schedule.

g. Use SNMP Version : (based on type select anyone of leave it OOTB)

Step4: Define the IPs for Discovery >

Once the schedule is defined save it.

From the related links click on 'Quick ranges'. A pop up must come up asking for IPs or subnets to discover. If you have multiple IPs/Subnet to discover enter the IPs/subnets in a comma seprated list. Once done click on 'Make Ranges'.

The F5 Discovery schedule page reload and create a Related list entry in 'Discover IP Ranges'. (an easy way to create Discovery IP range.)

Step5: Run Discovery >

Now your all set with what is needed for F5 discovery and time for real action now...

From the same realted link > click on ''Discover Now''

This will create a discovery status record were you can track the progress of discovery as like below....

Wait for Discovery Compleation...

Step6: Time to Debug and Fix >

There will be very less chances that your F5 discovery complete successfully in 1shot. If yes your lucky....

Lets fix the common issues that you may face...

a. Make sure you test your creds againts the IP and the MID server to see if creds have no issues.

b. Next, lets check if the ports which we requested to open are listening. to do so...

click on 'ECC queue' tab > search for shazzam input as like below. Open the record.

Verify if the port 161 is open, as like below....

Verify if your Creds and Ports are open from the above mentioned steps. (if your face issues with creds or connectivity the above steps will help to identify it, reach out to the consern team to get them fixed)

Step7: (Add SNMO OIDs for F5) >

If in case you still face issues ? your discovery gets completed and no CI gets created or if your have any classification issues or if your see 0 OR LESS OIDs in ECC queue... you would need to do the below step.

Navigate to the schedule > ECC Queue > Open the SNMP - Classify: 134 OIDs record > click on Payload XML.

Copy the SnmpObjectid which starts with dot and ending with 111, in your case it may be difference...

Navigate to >

Create an entry like below >

Re-run the discovery again... it must be successfull and CIs should have been created...

Feel free to comment below the errors/issues/quries that you face and ill be happy to help !

If you find the article to be useful or effective for your knowledge Kindly Consider Marking the article HELPFUL and BOOKMARK if for your future use...

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