This error indicates that DHCP has timed out without receiving a response from a DHCP server.

Things to try:

• Check that your DHCP server is online and responding to requests.

• Check your DHCP server logs. For example, if you are using ISC dhcpd, you should see something like

      dhcpd: DHCPDISCOVER from 00:18:f3:f0:9e:61 via eth0
      dhcpd: DHCPOFFER on 10.0.0.171 to 00:18:f3:f0:9e:61 via eth0
      dhcpd: DHCPREQUEST for 10.0.0.171 (10.0.0.6) from 00:18:f3:f0:9e:61 via eth0
      dhcpd: DHCPACK on 10.0.0.171 to 00:18:f3:f0:9e:61 via eth0

• Watch traffic on the DHCP server in real time

• tcpdump -i eth0

• After the failed DHCP attempt, check the output from the ifstat command to see if iPXE is receiving any packets (the “RX” counter) or experiencing receive errors (the “RXE” counter).

• Try configuring an appropriate static IP address on the iPXE client, using the iPXE command line. For example, to configure the static IP address 10.0.0.199/255.255.255.0:

      ifopen net0
      set net0/ip 10.0.0.199
      set net0/netmask 255.255.255.0

  Check that you can ping this IP address from your DHCP server.

• Try capturing a packet trace.

• If you are using Cisco networking equipment, then verify that portfast is enabled.

• If you are using iPXE inside a virtual machine with a bridged network, then you must set the bridge spanning tree interface startup forwarding delay to zero (Normally 15 seconds). You can do this using the command

  brctl setfd br0 0

  You may be able to configure this permanently via your system's network configuration files; e.g. by adding DELAY=0 to /etc/sysconfig/network-scripts/ifcfg-br0 (Redhat). On some systems the minimum delay is 2 seconds.

• If your VM bridge network doesn't have multiple routes, then you may not need STP at all, in which case set

  bridge_stp off

  in /etc/network/interfaces (Debian).

Advanced troubleshooting