dhcp_response probe fails to detect DHCP offer on RHEL 7.x

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Article ID: 222747

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Updated On:

Products

DX Infrastructure Management

Issue/Introduction

We have deployed dhcp_response probe (3.25) to a new build RHEL 7.9, dual-homed - Multiple NICS machine.

We are seeing:

- DHCP_response probe fails to issue DHCP request, using nominated IF, when it has no IP address

- DHCP_response probe fails to detect successful DHCP proffer from DHCP server (even though dhclient -r and then dhclient successfully gains a DHCP-lease on this IF and tcpdump shows successful request/offer.

Cause

The probe does not support multiple NIC/IP address.

Environment

Release : 20.3

Component : UIM - DHCP_RESPONSE

Resolution

The dhcp probe is unfortunately certified on RHEL 7.x 

Currently it can only run on RHEL 6.x


https://api-broadcom-ca.wolkenservicedesk.com/attachment/get_attachment_content?uniqueFileId=KBi2CKLxzVcI2VzPNMu4aQ==

CA UIM Probes Support Matrix (broadcom.com)

 

The main issue with RHEL 7.x is that the probe does not support multiple NIC/IP address.

 

Additional Information

RHEL 7.x is going to be an outdated/unsupported version of Linux shotly.

Broadcom is working on bringing support for RHEL 8.x which should come soon. 

 

Alternative Approach:

If only a multiple NIC server can be used for monitoring the DHCP server an alternative customized approach can be followed. 

The following is a custom procedure and Broadcom support does not offer configuration support for it. 

The alternative method consists in using a custom script to release and renew the DHCP lease, redirect the output to a file and then use nexec and logmon to automate and monitor the result.