PXE Boot error (TFTP IP in IPXE)



  • Hi all,

    I’m having an error connecting a PXE client. DHCP gives me the good ip in good range (10.171.27.xxx), but after TFTP in IPXE is 192.168.1.xxxx.
    Sometimes it’s works randomly and TFTP Ip is good.
    Fog server is 10.171.27.241

    My error
    1.jpg

    My /tftpboot/default.ipxe
    2.png

    Thanks for your help.


  • Moderator

    I’m going to say you have 2 dhcp servers on your network. Also since you are getting 192.168.1.1, I’m also going to predict you have a soho router/access point on your network.

    If the fog server and the target computer are on the same subnet (vlan) we can use the fog server to find out for sure if this is the case. You will have to do a little (not much) setup: https://forums.fogproject.org/topic/9673/when-dhcp-pxe-booting-process-goes-bad-and-you-have-no-clue

    You can either load the pcap into wireshark and look to see if you have 2 dhcp offers. If so you do have 2 dhcp servers on your network one will be your official dhcp server and the other will be your rogue dhcp server. If you can’t figure it out upload the pcap to a file share site and post the link here so we can review it for you.


  • Moderator

    @guilux Sorry I’m late to get back to this thread, but I’m glad you found the troublemaker!!

    I was going to tell you that now you have the mac address you can go to your network team and have them look at the mac tables to find out what port that device is connected to. That is the way to track it down. But you find it, so great!



  • I found the culprit
    2019-04-26 13_44_44-output.pcap.png

    Thank you so much George !!!



  • The output pcap
    output.pcap



  • Hi George,
    Thank you for your answer. This is my Output Pcap

    2019-04-26 11_56_40-output.pcap.png


  • Moderator

    I’m going to say you have 2 dhcp servers on your network. Also since you are getting 192.168.1.1, I’m also going to predict you have a soho router/access point on your network.

    If the fog server and the target computer are on the same subnet (vlan) we can use the fog server to find out for sure if this is the case. You will have to do a little (not much) setup: https://forums.fogproject.org/topic/9673/when-dhcp-pxe-booting-process-goes-bad-and-you-have-no-clue

    You can either load the pcap into wireshark and look to see if you have 2 dhcp offers. If so you do have 2 dhcp servers on your network one will be your official dhcp server and the other will be your rogue dhcp server. If you can’t figure it out upload the pcap to a file share site and post the link here so we can review it for you.


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