[syslinux] pxelinux stopped working after ...

[Geert Stappers]

Op 20080821 om 16:39 schreef 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.

My suggestion is to check firewall settings and name resolving settings.


I think firewall rules are blocking the TFTP transmission. ( TFTP has a
somewhat odd port usage ( opens are port number 69 and continues on a
hard to predict port )).  The test `tftp localhost` is done at the "good
side" of the FW, it is done _behind_ the firewall. 

Another reason for breakage on a "working setup" is that previous
(working) clients are known to the server. New clients are unknown to
the server. Unknown in the meaning of no name to an IP-address.
Solution is to make name resolving of the new clients possible.
( add then to domain name server setup  (or to /etc/hosts ))

> Thank you

Euh, it only are some suggestions.
Mostly to say: "I'm curious what did break an working setup"

> Tomas M

Cheers
Geert Stappers