PXEboot with Netgear router

[gabbas]

@george1421 Many thanks…will update the results here later on when.

[gabbas]

@george1421 said in PXEboot with Netgear router:

tcpdump -w output.pcap port 67 or port 68 or port 69 or port 4011

Hi george, When I run the above command on fog, i get nothing apart from: (I also boot the target machine at the same time):

fog@fog:~$  tcpdump -w output.pcap port 67 or port 68 or port 69 or port 4011   tcpdump:
fog@fog:~$

[george1421]

@gabbas You might have to do sudo before the tcpdump. But if the fog server can hear the dhcp request it should put what it hears in the output.pcap file.

[gabbas]

@george1421 Can you please see the file attached…Many thanks…I know I am bothering you too much…much appreciated.0_1488316537931_issue.pcap

[george1421]

@gabbas I’m sorry to tell you this but there are no dhcp packets in that capture. But there are others. SO I can tell you did not use the tcpdump command as I posted. That command should have only included the dhcp discussions.

Also just to reconfirm the dhcp server, fog server, and pxe booting computer are on the same IP subnet, right?

We are here to help, so it is no bother. I can tell you if it was a bother, I would not be here. I know we can get this worked out if we can get a solid dhcp packet capture.

[gabbas]

@george1421 Thanks. Yes I conform fog server, router and pxe client are on the same subnet…(192.168.1.0/24). I ran the tcpdump command as you posted…but nothing happens…see the out put when I run this command:

fog@fog:~$ sudo tcpdump -w output.pcap port 67 or port 68 or port 69 or port 4011
[sudo] password for fog:
fog@fog:~$ ifconfig

Does router’s IP address need to be put somewhere?

[george1421]

@gabbas Are you running that tcpdump command as root or the fog user?

If what you are seeing is true (the content of the output.pcap) file being 0 bytes then that also indicates that your fog server isn’t seeing any dhcp requests so dnsmasq will never send out the dhcp option 67 file name.

I can tell you that the command I posted does work, so I’m not sure why its not capturing things in your environment.

One idea, does your FOG server have more than 1 ethernet adapter?

[gabbas]

@george1421 Yes I also tried to run as root. The client only has 1 NIC…I dont know what’s really missing…

[Sebastian Roth]

@gabbas Something seems to be wrong here with tcpdump on your FOG server. After starting it you should see at least one or two lines of information. Something like this:

fog@fog:~$ sudo tcpdump -w output.pcap port 67 or port 68 or port 69 or port 4011
[sudo] password for fog:
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytes

The command sits there and waits. Leave it like this and fire up your client till you see the error message on the client. Then stop tcpdump (Ctrl+c) and upload the output.pcap file to the forums.

[gabbas]

@Sebastian-Roth …I think something is missing in my configuration…Good thing is we are getting a server soon so that will take care of DHCP…I will update the outcome here asap…many thanks…You guys are great…I have Fog setup (which I manage in out department at a university) and it works there like a charm without an issue…I dont know why its not working here…But I will figure it out…(with your assistance…)