Revision as of 00:30, 5 January 2008

You have a working Core/Hybrid and network - you start a new PC on the LMCE (internal) network, and you tell it to network boot (PXE) so that you can use it was an Media Director. The boot process starts but the PC does not successfully boot as a Media Director.

There are many reasons why this may happen:

Core/Hybrid is not on, operational (crashed) or unreachable on the network

For any diskless MD to boot, the Core/Hybrid provides serveral essential services as well as the files themselves, to boot from. If, for any reason, the Core/Hybrid is switched off, has crashed, some of its services not working correctly, or is simply not connected to the (right) network, then a Media Director (MD) will fail to boot.

Using a manageable switch with STP, where the ports are Blocking (eg Cisco enterprise switches)

Many switches use Spanning Tree Protocol (STP) which by default sets a port to "Blocking" and other non-Forwarding states for the first 50 seconds after a computer, connected to it, comes online. This is to allow time for the switch to confirm that there is no loop in your network related to that port, and during this period it will not pass any packets onto the rest of the LAN. This means your MD's network (PXE) boot process will almost certainly timeout and fail before the port goes into its Forwarding state. Power off/on, and in most cases, rebooting will simply restart the STP timer and end in the same timeout.

Assuming that you definitely do not have any loops in your network, you can bypass this checking process by configuring that port. Never do this to a port that connects to another switch - setting up a loop between switches or to the same switch, without this check can paralyse your network. For a Cisco switch, connect to your switch's management IP address with telnet and type:

enable

config t

interface e1/0 <- change e1/0 to the port's blade and port number

portfast enable

exit

write

[Can someone please correct these instructions?]

Then disconnect your telnet session.

Media Director is not on the internal (LMCE) LAN

The LMCE DHCP server, responsible for providing IP address leases, booting diskless Media Directors, and detecting new hardware (plug and play) entering the LMCE network, only services the "internal" LMCE network. Under normal (2 network card) installations of LMCE, the Core/Hybrid computer has 2 network cards, one connected to the "external" network - usually your normal home network, to which your broadband router and other computers may be connected. The second network card on the Core/Hybrid connects to the "internal" network - this is where all your Media Directors, media storage and other LMCE devices should be connected. The LMCE DHCP service resides on the Core/Hybrid, but by default it only "listens" for DHCP/Boot requests on the internal nework. If your new PC is not connected to this network, then it will not be able to boot as an MD.

DHCP server is not operational

The DHCP daemon must be running on the Core/Hybrid for an MD to be able to boot successfully. By default it will start up automatically as part of the Core/Hybrid boot process.

Ensure that the Core/Hybrid has had enough time to boot up completely before starting your MDs. If it still fails - check in Launch Manager and the log files to confirm that the DHCP daemon has started.

DHCP server has run out of leases

Normally there should be plenty of IP leases available in the default LMCE scope to service many MDs and other LMCE devices on the internal network. However, if you have a very large number of devices, or perhaps a network problem where leases are not being renewed properly, it is possible that you could run out of IP address to assign to newly booting devices, including MDs. If this happens, the MD will not be able to boot.

You need to troubleshoot your network configuration to eliminate any problems of lease renewal. Or if you have a large number of devices, you should use the Web Admin tool to increase your DHCP lease range.

Using VLANs

Most home networks do not have VLANs configured (or just a single one that all computers are connected to). A VLAN partitions some ports on a switch so that they cannot talk to others on the same switch (or other switches) without going through a router. This means that although your MD (or other devices) is connected to a port on the same switch as your Core/Hybrid's internal network interface, it will still not be able to communicate with the Core/Hybrid, and therefore the DHCP server.

Verify your VLAN configuration, and if possible remove all unnecessary VLANs or reassign the ports/patch cables, so that the MD can get to the Core/Hybrid's internal nework interface.

Second DHCP server is present on the same LAN segment

This can easily happen as many people use their broadband router to provide traditional DHCP services to non-LMCE hardware in their home.

NB: This existing DHCP server only provides basic IP configuration details, and cannot replace the LMCE DHCP server. The LMCE server provides other critical services to the LMCE environment.

However, both can co-exist as long as you use the standard 2 network card setup for LMCE. Ensure that the external network is separate from the internal network (eg different switches). The Core/Hybrid will provide DHCP services only for the internal network, and the broadband router will provide DHCP services only for the external network. Note that for LMCE to use media storage devices (PC shares, NAS's, etc) they must be connected to the internal network so that they are serviced by the LMCE DHCP service. There are ways around this, but they are not for the feint-hearted!

TFTP server is not operational

This is another critical service of LMCE, hosted on the Core/Hybrid. It is the basic file transfer system to get the LMCE Media Director software from the Core/Hybrid onto the booting Media Director PC.

Ensure first that the MD is booting on the correct (internal) network, as described above - you can see this easily from noting the IP address that the MD is granted during the network (PXE) boot process. If so, then check on the Core/Hybrid to ensure that the TFTP daemon is running correctly, from the Launch Manager and logs.