Missing DHCP Option 43 (PXE) with ip helper-address

[carsten.otto]

We used to boot out workstations with PXE boot but since we have implemented VLAN´s with ip helper adresses the workstations only get an IP but whrere not able to connect to the PXE Boot Server on Port 4011.

I have sniffed the communication an saw a difference in the DHCP packets. In the switched environment I can see a Option 43 with suboption 8, defining my PXE Server IP but with VLAN there is no PXE Boot Server Option.

We are using two Cat 4500 with VLAN and HSRP configured. The interface is in spanningtree portfast.

Any clue why ?

Carsten

[skarundi]

hi carsten,

If you sniff the DHCP server on the remote network, does it send a DHCP response with option 43 ?

If the DHCP response from the remote DHCP server has option 43 set, but the DHCP response relayed to the PXE client from the cat4500 doesn't then I'd suggest you open a TAC case so that TAC can investigate the issue.