Jump to content











Photo
- - - - -

Setting "siaddr" in DHCP header correctly


  • Please log in to reply
No replies to this topic

#1 Oli-DE

Oli-DE
  • Members
  • 1 posts
  •  
    Germany

Posted 06 July 2011 - 01:49 PM

Hi *,

I run TFTPd32 in a machine that has multiple NICs installed. Obviously, I don't want to "spam" the office network with my PXE stuff and operate a related "rogue" DHCP server there, so I thought I could limit TFTPd32 somewhat and bind it to just the one NIC facing the "test lab" network. However, Wireshark tells me that in the DHCP Offers that are being sent out, the header "siaddr" field specifying the next server to use (i.e. the TFTP server then) contains always the IP@ of the *first* NIC in the system, not the one I have explicitly bound TFTPd32 to and from which the DHCP offer is being sent out. Consequently, the client machine I want to PXE boot then tries to use a TFTP server in its next step which is in a completely different IP network and for which it has no route to, and thus fails.
As this is not per se a DHCP option, but already written in the header, I wouldn't see a (documented) way to change or overwrite this. Any good clue on what I am doing wrong, or is this possibly in fact a tiny bug...?

Many thanks,

CU/Oli.




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users