Is this the example your are using?
[QUOTE]
[SIZE=5][B][FONT=sans-serif][SIZE=19px][COLOR=#000000]dnsmasq.conf real DHCP server[/COLOR][/SIZE][/FONT][/B][/SIZE]
[FONT=sans-serif][COLOR=#000000]This acts as a normal DHCP server, passing out dhcp options 209/210 to pxelinux[/COLOR][/FONT]
[FONT=sans-serif][COLOR=#000000]How it works[/COLOR][/FONT]
[LIST]
[]Client boots and net card does a DHCP Discover, it will get a DHCP offer from dnsmasq
[]Client does a DHCP Request, which dnsmasq will ACK, telling it to get undionly.kkpxe.0 (as no option 175 “Etherboot”).
[]Client then gets undionly.kkpxe.0 via TFTP.
[]ipxe then does a DHCP Discover/offer/request/ack and dnsmasq should respond this time telling it to load pxelinux.0 via TFTP (now option 175 is set, so it no longer tries to pass unidonly.kpxe.0)
[]Passes DHCP options 209/210 passed, which pxelinux later looks at for the config path and document root.
[]pxelinux.0 loads via TFP.
[*]pxelinux then takes over boot process, all data now going via HTTP.
[/LIST]
[COLOR=#000000][FONT=monospace]enable-tftp[/FONT][/COLOR]
[COLOR=#000000][FONT=monospace]dhcp-match=ipxe,175[/FONT][/COLOR]
[COLOR=#000000][FONT=monospace]dhcp-range=192.168.2.100,192.168.2.200[/FONT][/COLOR]
[COLOR=#000000][FONT=monospace]tftp-root=/tmp/memstick/host0_part1/[/FONT][/COLOR]
[COLOR=#000000][FONT=monospace]dhcp-boot=net:#ipxe,undionly.kkpxe.0[/FONT][/COLOR]
[COLOR=#000000][FONT=monospace]dhcp-boot=pxelinux.0[/FONT][/COLOR]
[COLOR=#000000][FONT=monospace]dhcp-option-force=209,pxelinux.cfg/default[/FONT][/COLOR]
[FONT=monospace][COLOR=#000000]dhcp-option-force=210,[url]http://xxx.xxx.xx.xx:81/[/url][/COLOR][/FONT][/QUOTE]
It looks like you will may need to change dhcp-option-force=209,pxelinux.cfg/default also it seems like you may need to look into a undionly.kpxe config file.
[SIZE=4][B][FONT=sans-serif][SIZE=17px][COLOR=#000000] [/COLOR][/SIZE][/FONT][/B][/SIZE]
[QUOTE]
[SIZE=4][B][FONT=sans-serif][SIZE=17px][COLOR=#000000]pxelinux[/COLOR][/SIZE][/FONT][/B][/SIZE]
[FONT=sans-serif][COLOR=#000000]DHCP options 209/210 are use to configure pxelinux. These can either come forcibly set in a ipxe script or via the DHCP server normally.[/COLOR][/FONT]
[LIST]
[]209 = pxelinux config path, “pxelinux.cfg/default” . This relative to the ‘root’
[]210 = pxelinux ‘root’, “[URL=‘http://xxx.xxx.xx.xx:81/’][COLOR=#663366]http://xxx.xxx.xx.xx:81/[/COLOR][/URL]” . This is prefixed with HTTP (in this case on port 81) , so pxelinux will use instead of slow TFTP . It can also use FTP.
[/LIST]
[/QUOTE]