[ipxe-devel] iPXE tftp multicast help requested (connection timeouts)

[Erik Jacobson]

Some updates in case this inspires anybody's memory...

I have enabled syslog and have enabled extensive debugging in tftp and
ipv4. I added some additional debug statements of my own as well. I'm using
syslog because I've noticed wrapping / truncating of messages in my
serial-over-lan connection to iPXE.

Observations:
 - The first 'Sending ACK for block 0' is from tftp_rx_oack()
 - The other 'Sending ACK for block 0' are sent from tftp_timer_expired()
 - When enabling ipv4 debugging, I'm observing that the multicast packets
   seem to be rejected even though they are relevant for the transfer. I
   know rejecting of irrelevant broadcast/multicast packets is normal but
   I think the good ones are being rejected as well for some reason.

Here are some lines from iPXE captured by the syslog server. It seems to
show us sending the ACKs for block 0, getting multicast packets from the
atftpd server (239.255.0.0 is the IP used by atftpd, confirmed in atfpd
messages), and iPXE rejecting those. So I'll keep digging further.

If I had more experience with the network stack I suppose this would be
much easier. I'm sort of learning as I go here :)

Suggestions welcome.

Dec 10 09:02:34 service0 service0.head.ice.americas.sgi.com ipxe: TFTP 0xd11d4 multicast port 1758
Dec 10 09:02:34 service0 service0.head.ice.americas.sgi.com ipxe: erikj in tftp_rx_oack, about to tftp_send_packet
Dec 10 09:02:34 service0 service0.head.ice.americas.sgi.com ipxe: TFTP 0xd11d4 sending ACK for block 0
Dec 10 09:02:34 service0 service0.head.ice.americas.sgi.com ipxe: IPv4 TX 172.23.0.9->172.23.0.1 len 32 proto 17 id d0af csum 51e5
Dec 10 09:02:34 service0 service0.head.ice.americas.sgi.com ipxe: erikj in tftp_rx_oack, done with tftp_send_packet
Dec 10 09:02:34 service0 service0.head.ice.americas.sgi.com ipxe: IPv4 RX 239.255.0.0<-172.23.0.1 len 38 proto 17 id 0000 csum ddaf
Dec 10 09:02:34 service0 service0.head.ice.americas.sgi.com ipxe: IPv4 received packet rejected by stack: The socket is not connected (http://ipxe.org/380f6001)
Dec 10 09:02:34 service0 service0.head.ice.americas.sgi.com ipxe: erikj in tftp_timer_expired, about to tftp_send_packet
Dec 10 09:02:34 service0 service0.head.ice.americas.sgi.com ipxe: TFTP 0xd11d4 sending ACK for block 0
Dec 10 09:02:34 service0 service0.head.ice.americas.sgi.com ipxe: IPv4 TX 172.23.0.9->172.23.0.1 len 32 proto 17 id d7b0 csum 4ae4
Dec 10 09:02:34 service0 service0.head.ice.americas.sgi.com ipxe: erikj in tftp_timer_expired, done with tftp_send_packet
Dec 10 09:02:34 service0 service0.head.ice.americas.sgi.com ipxe: IPv4 RX 239.255.0.0<-172.23.0.1 len 38 proto 17 id 0000 csum ddaf
Dec 10 09:02:34 service0 service0.head.ice.americas.sgi.com ipxe: IPv4 received packet rejected by stack: The socket is not connected (http://ipxe.org/380f6001)