Deployment Solution

PXE booting makes it possible to boot a computer completely from the network without the help of any storage device on the destination computer(except RAM) . During the PXE process, the PXE client boots up, starts up the PXE boot ROM and now the PXE boot ROM sends a DHCP request. The responding DHCP request will have an additional DHCP option, the "filename" options. At this point of time, the PXE client attempt to download the file specified over TFTP.After downloading the file successfully, the PXE client now executes it . This is how PXE works. It is very clear that network has the major role in PXE booting. The network must be properly configured for PXE.

PXE clients require an IP address from a DHCP server to begin the remote installation process. If there is a router present between the PXE client and the DHCP server, the client may not receive an IP address from the DHCP server. Without this information, the installation on the PXE client does not work. DHCP clients located across a router from a DHCP server require that the router is to be configured to forward DHCP traffic to a DHCP server on a remote subnet. This traffic is broadcast traffic and routers do not normally forward broadcast traffic unless configured to do so. A network router can be a hardware-based router or software-based.

In either case, you need to configure the router to relay DHCP traffic to designated DHCP servers. The DHCP server IP addresses are configured on the router on a per-interface basis using IP helper functionality, or in the case of RRAS, using the DHCP relay agent. We need to make sure that the DHCP server is able to hear the broadcast messages from the clients. Most of the ethernet switches are transparent to broadcast messages but the IP routers are not. Most of the IP routers are configured to block ethernet broadcast messages. With the help of DHCP relay agent feature, it is possible for the DHCP server to support clients that are on the same subnet and even the ones that are on different subnets.This means with the help of routers enabled with the DHCP Relay Agent, a single DHCP server is able to provide service to DHCP client systems on multiple subnets.

Caution: Need to configure a separate DHCP scope for each subnet.

PXE-E55 error is caused by many reasons. Mostly it means your PXE client fails to see the TFTP Server. Now, The first thing that we need to check is whether or not the routers (or switches) are properly configured for PXE. Once we are done with this, ensure that the server static IP and the DHCP IP range on the same subnet. Issues might come with 60 option when you add it to dhcp server global scope instead of adding it to the IP range scope.

PXE-E11: ARP timeout:

The PXE client makes the ARP request (for the router IP) four times, and if it does not get any valid ARP replies, this message is displayed. This error can occur because of many reasons. You would get this error if you set the DHCP Class Identifier (option 60) on the DHCP server and install the ProxyDHCP on a separate machine. Again routers that do not respond to ARP requests can be a reason for this error.

PXE-E32: TFTP open timeout:

The "PXE-E32" error indicates that the PXE client was able to get a DHCP address and a boot file name, but timed out when attempting to download the boot file using TFTP. It indicates that the PXE did not get a reply from the TFTP server when sending a request to download its boot file. This can happen if the TFTP server is not present or if the TFTP server is not running. And also when TFTP and DHCP/BOOTP services are running on different machines, but the next-server (066) option was not added to the DHCP server configuration. Make sure that this is added and set the option's value to the IP address of the TFTP server. If multicast is disabled by the switches in the environment, either enable multicast or change the configuration of the PXE server to use regular TFTP.

PXE-E51: No DHCP or proxyDHCP offers were received:

The "PXE-E51" indicates that the client did not receive any valid DHCP, BOOTP or ProxyDHCP offers. This error occurs when DHCP services are not available on the network to which the PXE-enabled NIC is connected or if DHCP proxy or IP helper address is not configured for the subnet on which the PXE client is connected. Again, if DHCP is available but PXE is not available on the network, this error occurs. Even simple things like network cable not attached to PXE-enabled NIC on the target server can cause this issue.

PXE-E53: No boot filename received:

The "PXE-E5" indicates that the client received at least one valid DHCP/BOOTP offer, but does not have a boot filename to download. This happens when the DHCP Server and the PXE Server were located on the same server, but one of them was moved to a different server which results in incorrect PXE server configuration. This can be fixed by re-installing the PXE server component. And if the DHCP relay agent, either a Proxy DHCP Server or a switch configured with helper addresses, is not configured correctly, one can get this PXE error.