[syslinux] pxelinux aborts booting

[H. Peter Anvin]

Christian Hoefer wrote:
> Hi,
> i try booting a PXE equipped client with pxelinux.
> 
> The problem is: after receiving the file pxelinux.0 it requests
> pxelinux.cfg/C0A86451 and aborts.
> tcpdump:
> ....
> 16:01:58.786946 192.168.100.81.2073 > saturn.1337:  udp 4
> 16:01:58.787033 saturn.1337 > 192.168.100.81.2073:  udp 516 (DF)
> 16:01:58.787202 192.168.100.81.2073 > saturn.1337:  udp 4
> 16:01:58.787528 saturn.1337 > 192.168.100.81.2073:  udp 516 (DF)
> 16:01:58.787703 192.168.100.81.2073 > saturn.1337:  udp 4
> 16:01:58.787793 saturn.1337 > 192.168.100.81.2073:  udp 348 (DF)
> 16:01:58.787932 192.168.100.81.2073 > saturn.1337:  udp 4
> 16:01:58.827477 192.168.100.81.57217 > saturn.tftp:  52 RRQ
> "/var/tftpboot/pxelinux.cfg/C0A86451"
> 16:02:03.755659 saturn.1336 > 192.168.100.81.2072:  udp 516 (DF)
> 16:02:08.755776 saturn.1336 > 192.168.100.81.2072:  udp 516 (DF)
> 16:02:08.860782 saturn.1337 > 192.168.100.81.57217:  udp 216 (DF)
> 16:02:08.860914 192.168.100.81.57217 > saturn.1337:  udp 26
> 
> at this point the client resets. 192.168.100.81 is the client, saturn
> is the dhcp/tftp server.
> 
> The syslinux docu says:
> 
> + The error recovery routine doesn't work quite right.  For right
>  now, it just does a hard reset - seems good enough.
> 

After five seconds, yes.  I've gotten a few reports that seem to
indicate the delay loop isn't working right; I will check into that
before releasing 1.76.

> and that's exactly what it does. And i have no chance to know why.
> /var/tftpboot/pxelinux.cfg/C0A86451 exists and is readable to tftpd.
> I'm allmost 100% sure it is syntactically correct. But from tcpdump i
> see it is never loaded (and parsed).

It's loaded, it's right there in your tcpdump:

 16:01:58.827477 192.168.100.81.57217 > saturn.tftp:  52 RRQ
> "/var/tftpboot/pxelinux.cfg/C0A86451"
16:02:08.860782 saturn.1337 > 192.168.100.81.57217:  udp 216 (DF)
16:02:08.860914 192.168.100.81.57217 > saturn.1337:  udp 26

Looks like your TFTP serrver doesn't support the tsize option.

	-hpa