Hosts losing DHCP after being upgraded or rebooted when ESXi firewall Allowed IP list is in use for DHCP service.

Products

• VMware vSphere ESXi

Issue/Introduction

One or more of the following issues may be seen when using allowed IP list and DHCP.

• ESXi vmkernel management may not be able to get a DHCP address.
• Auto Deployed hosts may not come up with a DHCP address.
• In hostd.log. Hostd[] [Originator@ sub=Vimsvc.ha-eventmgr] Event 14 : Unable to obtain a DHCP lease on interface vmk0.
• In dhclient.log
  • DHCPDISCOVER on vmk0 to 255.255.255.255 port <#> interval 6 
  • ipv4: Failed, invalid lease
  • No DHCPOFFERS received

 

Environment

This requires the Allowed IP list to be set in the ESXi firewall for DHCP client service. 

Cause

During the DHCPDISCOVER process. A packet will reach out to a destination IP of 255.255.255.255. This is a protocol requirement.

Resolution

When configuring Allowed IP addresses for the DHCP client service in the ESXi firewall, these IP addresses need to be included for DHCP functionality:

• DHCP servers or DHCP forwarder IP
• DHCP Discover address of 255.255.255.255