>>>>> "Keith" == Keith Lofstrom <[email protected]> writes:
Keith> After beating my head against the OpenWRT wall for weeks - one Keith> thing after another not working as expected [...] Russell> Not to say there isn't a learning curve with OpenWrt, but Russell> ... you could have asked me more questions! I am a willing Russell> resource, if possessing finite capacity, but I would Russell> certainly be (have been) eager to try to help. Keith> Again, the stumper was related to the Verizon connection and Keith> udhcpc, and that is a real bastard of a problem to help with Keith> remotely. I'd be happy to come out there some afternoon and help diagnose. Keith> I was having trouble enough trying to get tcpdump to provide Keith> useful data - as I understand it, it won't listen to a port Keith> before it is up, and it is the DHCP handshake that I care Keith> about. >From the Alix, it works for me. I just got my Alix (w/ OpenWrt r12615) out and tried. I hooked up a serial console. Without eth0 plugged into the Alix, I boot up to a console. The I run: # tcpdump -i eth0 -s0 -w/tmp/capture.pcap then plug the cat5 into eth0, wait 15-30 seconds, and then stop tcpdump with a Ctrl-C and scp the capture.pcap somewhere with wireshark and decode it. I see something like this: r...@openwrt:/tmp# tcpdump -i eth0 -s0 -w /tmp/capture.pcap device eth0 entered promiscuous mode tcpdump: WARNING: eth0: no IPv4 address assigned tcpdump: listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytseth0: link up, 100Mbps, full-duplex, lpa 0x45E1 ^Cdevice eth0 left promiscuous mode 7 packets captured 7 packets received by filter 0 packets dropped by kernel That will give you half of what you need. The other half is a similar packet capture with the working device (the Actiontec or whatever). For that, you'll probably need a network *hub* (or a linux bridge[1] or similar) in between the CPE and the working router, and a laptop or something to capture the packets. Then compare what is going back and forth. Since you need to set that up anyway to compare, you might as well do that for both devices. I've got a 10Mbps hub if you need one. My wild-assed guess is that the Verizon is looking for some hostname option or something. The udhcpc in OpenWrt is from busybox. It's got a bunch of options. To get a listing, try: # udhcpc --help to get a listing. I suspect some appropriate tweaking to those things will get it fixed up, but a packet capture comparison will let you converge a lot faster on exactly what "appropriate" means in this context. [1] It occurs to me that one of these 3-port Alix could make a cool transparent bridge for this kind of sniffing. Use one of the ports to ssh in from your laptop, and use the other two bridged together to do your sniffing. With the right incantation, you could use the Alix to do all the sniffing: as an end-point when you are testing it; as a man-in-the-middle when you are figuring out what the Actiontec is doing differently. -- Russell Senior, Secretary [email protected] --~--~---------~--~----~------------~-------~--~----~ The Personal Telco Project - http://www.personaltelco.net/ Donate to PTP: http://www.personaltelco.net/donate Archives: http://news.gmane.org/gmane.network.wireless.portland.general/ Etiquette: http://www.personaltelco.net/index.cgi/MailingListEtiquette List information: http://lists.personaltelco.net To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] -~----------~----~----~----~------~----~------~--~---
