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I have 2 VMs. One is setup as a pxe server (dhcpd with a specific subnet and a tftpserver). The second VM is networked with 'vboxnet2' to first VM and it is able to get the DHCP IP as specified my VM1's DHCPD, but fails to download the specified file specified in 'filename ' of dhcpd.conf.

None in here : https://docs.oracle.com/cd/E19045-01/b200x.blade/817-5625-10/Linux_Troubleshooting.html helped.

So:

I tried a tftp download from VM1 and it seems to download the exact file ( path and tftp listening seems fine )
I tried tcpdump and the VM1 seems to receive the packets but no debug log in syslog ( which I usually see.
I added iptables entry to accept all from VM2 IP.
What else can i do so my tftpd receives the request ?
Victor
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1 Answers1

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A wireshark traffic capture from your Server VM will sure help.

You say that the DHCP gives the IP and PXE info right? are you sure you have only one DHCP server in your set up?

are you sure the IP that the DHCP server gives belongs to he corresponding sub-net?

If you check these things outs you will probably find the client is getting the IP from a secondary DHCP server without PXE info or the DHCP provides a wrong subnet IP, etc typical PXE stuff....

EDIT:

Please consider if there is another DHCP in your scenario, the client might be i.e. taking the wrong offer... First you should rule out the multiple DHCP option. Next analyze the DHCP offer and check the "next server" field (or the option 66) which should carry the TFTP IP address, next check the TFTP server really receives a properly formed request, next try to see if there's a TFTP firewall issue considering TFTP is a protocol that receives the initial request on port 69 but next uses a randomly selected port for data transfer

Pat
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  • yes, Iam sure because, I specify the MAC in dhcpd.conf. Also wireshark is same as tcpdump and it seems to receive the request but tftpd is not able to receive it. – Victor Apr 04 '16 at 14:56
  • see my answer edit. – Pat Apr 04 '16 at 15:08
  • seems to be:# tcpdump -vv -i enp0s8 port tftp tcpdump: listening on enp0s8, link-type EN10MB (Ethernet), capture size 65535 bytes 17:16:14.802533 IP (tos 0x0, ttl 20, id 2, offset 0, flags [none], proto UDP (17), length 64) 10.10.10.121.ah-esp-encap > 10.10.10.111.tftp: [udp sum ok] 36 RRQ "pxelinux/pxelinux.0" octet tsize 0 – Victor Apr 04 '16 at 17:18
  • I want to know if there is anything after tftp request is received by kernel and before it is handed off to the tftpserver ? I can think of only iptables – Victor Apr 04 '16 at 17:21
  • you might have iptables/firewall rules in between. Consider probably the server received the request but its answer is somehow blocked. or you just did not set the TFTP service correctly. – Pat Apr 05 '16 at 09:06
  • @Victor are you still alive to accept a answer or to solve the issue and answer it? – djdomi May 28 '23 at 16:49