The current DHCPv4 protocol implementation does not associate requests with responses. The protocol is not strictly request -> response or simply one request, one response (there can be one response from each DHCP server for a high-availability deployment).

I think response times could be measured for both discover/offer and request/ack exchanges.

• DHCPDISCOVER -> DHCPOFFER (multiple offers are possible)
  • Send one event for each offer so that we report the response time for each server.
• DHCPREQUEST -> DHCPACK/NAK (should be just one)
• DHCPDECLINE (no measurement)
• DHCPRELEASE (no measurement)

original comment: #7647 (comment)