Virtual machines are not receiving DHCP offers on a distributed port group.

Products

• VMware NSX

Issue/Introduction

• Virtual machine's DHCP IP renewal requests are not completing.
• Virtual machine are connected to a distributed port group.
• Virtual Machine's are sending DHCP Discover Messages but not seeing any Offer request.
• Packet Capture on the DHCP VM' shows it sending an Offer to the Client VM's.
• Packet Capture on the Client show only Discover Messages.

Environment

• VMware vSphere ESXi
• VMware NSX

Cause

• Its as NSX configured  Environment.
• NSX Segment Security Policy "default-segment-security-policy" has DHCP Server Block enabled by default. 
• DHCP Server Block blocks traffic from a DHCP server to a DHCP client.
• DHCP Client Block prevents a VM from acquiring a DHCP IP address by blocking DHCP renewal requests.
  
  
  

Resolution

• Create a new Segment Security Profile and ensure that the DHCP Server Block setting is disabled.
• Apply the newly created Segment Security Profile to the affected segment(s), replacing the default “default-segment-security-policy”.