[K12OSN] Guidance on troubleshooting - new RHEL6 + LTSP won't PXE

[Shawn Wells]

Hello,
	
	I'm hoping someone can set me in the right direction to troubleshoot a 
problem I'm encountering. Ultimately PXE booting doesn't seem to be 
working for me.

	I loaded two VMs with RHEL6.1 and pulled down the latest updates, then 
I followed the Install Guide [1] without issues.  The ltsp-server-tweaks 
didn't function for me, but in reading through the mailing list it looks 
like this can be over looked (at least temporarily).

	Per the instructions I configured ltspbr0 and tried to PXE boot the VM 
which is acting as the thin client... no luck.  My config is just two 
VMs for testing purposes.

	I receive the following error:
PXE-E51: No DHCP or proxyDHCP offers were received.


	On the server I have two NICs, one giving internet access and the other 
for TCs.  My config for the server:

/etc/sysconfig/network-scripts/ifcfg-eth1
DEVICE=eth1
BOOTPROTO=none
TYPE=Ethernet
HWADDR=00:1c:42:70:0b:0a
IPV4_FAILURE_FATAL=no
IPV6INIT=no
ONBOOT=yes
USERCTL=no
NM_CONTROLLED=no
BRIDGE=ltspbr0

/etc/sysconfig/network-scripts/ifcfg-ltspbr0
ONBOOT=yes
IPADDR=172.31.100.254
DEVICE=ltspbr0
TYPE=Bridge
BOOTPROTO=static
STP=off
DELAY=0.1
USERCTL=no
IPV6INIT=no
PEERDNS=yes
NETMASK=255.255.255.0
ARP=yes
	
	After failing to PXE boot I loaded an OS on the thin client and was 
able to ping 172.31.100.254, so it doesn't appear to be a connectivity 
issue.

	I went ahead and rebooted my server, then tried to PXE again.  No dice.

	I ensured DHCP is running and listening for connections:
# chkconfig --list | grep dhcp
ltsp-dhcp	0:off	1:off	2:on	3:on	4:on	5:on	6:off

# service ltsp-dhcp status
dhcpd (pid 1920) is running...

$ netstat -an | fgrep -w 67
udp	0	0.0.0.0:67	0.0.0.0:*


	I then ensured tftp was running and enabled
# chkconfig --list | grep tftp
	tftp:	on

# netstat -an | fgrep -w 69
udp	0	0.0.0.0:69	0.0.0.0:*

	From there I installed a TFTP client:
# yum -y install tftp
# cd /tmp
# ftp 172.31.100.254
tftp> status
Connected to 172.31.100.254
Mode: netascii Verbose: off Tracing: off Literal: off
Rexmt-interval: 5 seconds, Max-timeout: 25 seconds
tftp> get ltsp/x86_64/pxelinux.cfg
tftp> quit
(the file did download)

	I ensured my firewall was stopped
$ sudo service iptables stop; chkconfig iptables off

	I even temporarily turned SELinux off
# setenforce 0

	Thoughts MORE than welcome! Thanks for any help!

-Shawn