[syslinux] pxelinux stopped working

[Tomas M]

Hello.

Some time ago, everything worked for me.
But now it is very strange, it does no more work (using exactly the same setup)
Do you have any idea how to find out what's wrong?

Here is my situation:
I am trying to boot over PXE.
TFTP server is running. DHCP server is running from the same machine. Both by dnsmasq.
TFTP server has the following files and directories:
/pxelinux.cfg/pxelinux.0
/pxelinux.cfg/default
I can use 'tftp localhost' (using tftp-hpa) and type 'get /pxelinux.cfg/default' command which downloads the default config file. Seems there is problem here on server.

The client initiates DHCP requests. Client receives response from the server, assigns a new (unique) IP address to itself and it downloads pxelinux.0 file. Then it starts that file. Then pxelinux tries to download pxelinux.cfg/123456789ABCD and so on, and also it tries pxelinux.cfg/default and then it dies with a message "Unable to locate configuration file". But it's there! :)

Syslog on the server shows a strange message from dnsmasq:
TFTP error 0 TFTP Aborted received from 172.16.73.122
FTFP failed sending /boot/pxelinux.cfg/pxelinux.0 to 172.16.73.122

Whats up? Anybody have any idea? :)
I know pxelinux.0 has been sended to the client for sure, because it is executed there, and it searches for the default config at the first place ... 

Hope somebody could suggest how to track down where the problem is.

Thank you

Tomas M