Re: DHCP client failure with cable modem
On Fri, Feb 22, 2008 at 10:16:18PM -0800, David Murphy wrote: --- johan beisser [EMAIL PROTECTED] wrote: Ok. When you initially plug in the modem side interface, what does it see? Do a basic tcpdump, and watch the traffic for the dhcp assignment. Secondly, could you forward your pf.conf? Well now I'm *really* baffled. I read the manpage for tcpdump, got all set to capture the interface when I plugged in and when I did a netstart... and the darn thing just decided to work. I made no changes to the setup since my last set of failed attempts, and I didn't do anything I haven't tried twice already. This is exactly what happend to me a couple weeks ago. The dhclient program wouldn't get an IP for the external interface. I tried rebooting the cable modem, rebooting the OpenBSD box, and doing a 'sudo sh /etc/netstart'. PF wasn't blocking the dhcp packets and there were no error messages in any of the log files. I was about to call my ISP and then it magically just worked and has worked flawlessly for about a month straight. ...? Ugh. I've definitely looked at this enough tonight, but tomorrow I'm gonna do some powerdowns and powerups and see if there's any sort of consistency now. Thanks for talking me through it anyway, folks. David Murphy Never miss a thing. Make Yahoo your home page. http://www.yahoo.com/r/hs -- Sean Malloy Home Page: www.catgrepsort.com
DHCP client failure with cable modem
Greetings folks. This week I undertook a project to replace my cheapo home broadband router with an old laptop running OpenBSD. Success appeared to have been achieved, but I've run into a snag in the final implementation. I set up the OBSD router (more info below) to perform NAT and serve DHCP and DNS for my LAN. After a ridiculously small amount of tweaking, I got everything working just like I wanted it. Here was the arrangement: (Test hosts) - (Switch) - (OBSD router) - (Cheapo router) - (Cable Modem) The cheapo router was still in the loop because I didn't want to disconnect the rest of my LAN before I was ready. Yesterday I decided I was ready. I removed the cheapo router and plugged the OBSD router directly into the modem, there was some rebooting of devices involved, and my desktop could no longer access the internet. A little sleuthing revealed that the router was unable to retrieve an address from the modem. I've done some poking around and searched the list archives. There were a couple of threads with similar issues, but no definitive solutions that I found. There were references to cable modems only wanting to serve one hardware address, but I'm able to use it with either the cheapo router, or with my desktop plugged directly into it (and I verified that the modem saw them as two different hardware addresses... no weird proxying going on in the router). I powered the modem completely down for a few minutes and plugged only the OBSD router into it when I brought it back up, but still no luck. The hostname.ep1 file for that interface is a simple dhcp NONE NONE NONE. The dhclient.conf file is the default, which includes send host-name hostname;, the only other helpful suggestion I saw in the list archives. I've tried multiple cables and NICs, to rule out hardware. I checked the dhclient.conf file on the Ubuntu desktop that pulls an address from the modem just fine (which is this one, so I'm sure it really works), and while not identical, it's only configured to send the hostname as well. I've hit dead ends with everything now, and so any further suggestions are quite welcome. More info on the OBSD box: It's an old Toshiba Satellite 330CDS. I installed OBSD 4.2 with just base42, etc42, and man42. The only non-stock program running is isc-dhcp-server-3.0.4p0.tgz, which I installed in order to get dynamic DNS going. The laptop has two PCMCIA NICs, ep1 (external) and ne3 (internal). The setup was done primarily by bending the following two guides to my setup: http://www.openbsd.org/faq/pf/example1.html http://www.bsdguides.org/guides/openbsd/networking/dynamic_dns_dhcp.php The former is just the sample home router from the PF guide, and the latter addresses DHCP and DNS. Thanks in advance for any suggestions. David Murphy Never miss a thing. Make Yahoo your home page. http://www.yahoo.com/r/hs
Re: DHCP client failure with cable modem
On Fri, Feb 22, 2008 at 6:11 PM, David Murphy [EMAIL PROTECTED] wrote: Greetings folks. This week I undertook a project to replace my cheapo home broadband router with an old laptop running OpenBSD. Success appeared to have been achieved, but I've run into a snag in the final implementation. I set up the OBSD router (more info below) to perform NAT and serve DHCP and DNS for my LAN. After a ridiculously small amount of tweaking, I got everything working just like I wanted it. Here was the arrangement: (Test hosts) - (Switch) - (OBSD router) - (Cheapo router) - (Cable Modem) The cheapo router was still in the loop because I didn't want to disconnect the rest of my LAN before I was ready. Yesterday I decided I was ready. I removed the cheapo router and plugged the OBSD router directly into the modem, there was some rebooting of devices involved, and my desktop could no longer access the internet. A little sleuthing revealed that the router was unable to retrieve an address from the modem. I've done some poking around and searched the list archives. There were a couple of threads with similar issues, but no definitive solutions that I found. There were references to cable modems only wanting to serve one hardware address, but I'm able to use it with either the cheapo router, or with my desktop plugged directly into it (and I verified that the modem saw them as two different hardware addresses... no weird proxying going on in the router). I powered the modem completely down for a few minutes and plugged only the OBSD router into it when I brought it back up, but still no luck. The hostname.ep1 file for that interface is a simple dhcp NONE NONE NONE. The dhclient.conf file is the default, which includes send host-name hostname;, the only other helpful suggestion I saw in the list archives. I've tried multiple cables and NICs, to rule out hardware. I checked the dhclient.conf file on the Ubuntu desktop that pulls an address from the modem just fine (which is this one, so I'm sure it really works), and while not identical, it's only configured to send the hostname as well. I've hit dead ends with everything now, and so any further suggestions are quite welcome. More info on the OBSD box: It's an old Toshiba Satellite 330CDS. I installed OBSD 4.2 with just base42, etc42, and man42. The only non-stock program running is isc-dhcp-server-3.0.4p0.tgz, which I installed in order to get dynamic DNS going. The laptop has two PCMCIA NICs, ep1 (external) and ne3 (internal). The setup was done primarily by bending the following two guides to my setup: http://www.openbsd.org/faq/pf/example1.html http://www.bsdguides.org/guides/openbsd/networking/dynamic_dns_dhcp.php The former is just the sample home router from the PF guide, and the latter addresses DHCP and DNS. Thanks in advance for any suggestions. David Murphy Firstly, post something that might help someone troubleshoot your problems. Something like a dmesg and any errors that dhclient is producing. Disable everything until you can get dhclient to work. Are you blocking dhcp packets with pf? Is your local dynamic DNS service screwing with your upstream DHCP? Maybe try unplugging your cable modem for a bit, sometimes they get picky about how many MAC addresses they'll give IPs to. --david
Re: DHCP client failure with cable modem
David Higgs wrote: On Fri, Feb 22, 2008 at 6:11 PM, David Murphy [EMAIL PROTECTED] wrote: Greetings folks. This week I undertook a project to replace my cheapo home broadband router with an old laptop running OpenBSD. Success appeared to have been achieved, but I've run into a snag in the final implementation. I set up the OBSD router (more info below) to perform NAT and serve DHCP and DNS for my LAN. After a ridiculously small amount of tweaking, I got everything working just like I wanted it. Here was the arrangement: (Test hosts) - (Switch) - (OBSD router) - (Cheapo router) - (Cable Modem) The cheapo router was still in the loop because I didn't want to disconnect the rest of my LAN before I was ready. Yesterday I decided I was ready. I removed the cheapo router and plugged the OBSD router directly into the modem, there was some rebooting of devices involved, and my desktop could no longer access the internet. A little sleuthing revealed that the router was unable to retrieve an address from the modem. I've done some poking around and searched the list archives. There were a couple of threads with similar issues, but no definitive solutions that I found. There were references to cable modems only wanting to serve one hardware address, but I'm able to use it with either the cheapo router, or with my desktop plugged directly into it (and I verified that the modem saw them as two different hardware addresses... no weird proxying going on in the router). I powered the modem completely down for a few minutes and plugged only the OBSD router into it when I brought it back up, but still no luck. The hostname.ep1 file for that interface is a simple dhcp NONE NONE NONE. The dhclient.conf file is the default, which includes send host-name hostname;, the only other helpful suggestion I saw in the list archives. I've tried multiple cables and NICs, to rule out hardware. I checked the dhclient.conf file on the Ubuntu desktop that pulls an address from the modem just fine (which is this one, so I'm sure it really works), and while not identical, it's only configured to send the hostname as well. I've hit dead ends with everything now, and so any further suggestions are quite welcome. More info on the OBSD box: It's an old Toshiba Satellite 330CDS. I installed OBSD 4.2 with just base42, etc42, and man42. The only non-stock program running is isc-dhcp-server-3.0.4p0.tgz, which I installed in order to get dynamic DNS going. The laptop has two PCMCIA NICs, ep1 (external) and ne3 (internal). The setup was done primarily by bending the following two guides to my setup: http://www.openbsd.org/faq/pf/example1.html http://www.bsdguides.org/guides/openbsd/networking/dynamic_dns_dhcp.php The former is just the sample home router from the PF guide, and the latter addresses DHCP and DNS. Thanks in advance for any suggestions. David Murphy Firstly, post something that might help someone troubleshoot your problems. Something like a dmesg and any errors that dhclient is producing. Disable everything until you can get dhclient to work. Are you blocking dhcp packets with pf? Is your local dynamic DNS service screwing with your upstream DHCP? Maybe try unplugging your cable modem for a bit, sometimes they get picky about how many MAC addresses they'll give IPs to. --david Forgive me but I will ask a very stupid question. Did you use a cross over cable when you connected the OpenBSD box to switch. Your switch should also have a button for one of its LAN plugs so that when you use regular CAT 5 cable it reverse the stream so that you do not need to buy cross over cable. If the hardware set up is OK you will really need to give much more info about the network and OpenBSD box in particular so that people can trouble shut. Best, Predrag
Re: DHCP client failure with cable modem
--- Chris Kuethe [EMAIL PROTECTED] wrote: I've seen cases where you can only have one client ethernet address on your cable modem, and you need to reset everything and give your old mac address a chance to time out. you might want to: a) change the external address of your openbsd machine to that of your old cheapo router, or b) power off your cable modem for half an hour and retry, or c) call tech support and get them to reset your cable modem. As stated I've demonstrated that the modem is happy to work with either the cheapo router or directly with my desktop, and I verified that it sees them with separate hardware addresses. So it's not hung up on one in particular. I've brought the modem down for a few minutes, but I could give it a longer test. --- David Higgs [EMAIL PROTECTED] wrote: Firstly, post something that might help someone troubleshoot your problems. Something like a dmesg and any errors that dhclient is producing. Yeah, I wasn't very specific about that, was I? When I watch it try to grab an address as it boots, it simply tries DHCPREQUEST for a bit (asking for the address it had when it was plugged into the cheapo router), then switches to DHCPDISCOVER. After a bunch of those, it says No DHCPOFFERS received., and sets itself up with the last address it had from the cheapo router. I've also done sh /etc/netstart ep1 after boot, with the same effect. The very last time I tried it, there was one difference I hadn't seen before: after the first DHCPREQUEST, it received a DHCPNAK from an address that appears to be upstream in the ISP's framework. Still no response to the DHCPDISCOVERs, though. dmesg doesn't show anything interesting. Disable everything until you can get dhclient to work. Are you blocking dhcp packets with pf? Is your local dynamic DNS service screwing with your upstream DHCP? This setup works just fine when I insert the cheapo router between the modem and the OBSD router, so pf isn't doing any funny-business. There's some difference between the router's DHCP and the modem's DHCP that I can't figure out, and that my desktop machine doesn't notice. Maybe try unplugging your cable modem for a bit, sometimes they get picky about how many MAC addresses they'll give IPs to. Alright, I'll unplug it overnight and we'll see what happens in the morning. Thanks for the responses. David Murphy PS: another piece of info I left out is that my modem is a Motorola Surfboard SB5120, and my cable ISP is Charter. Looking for last minute shopping deals? Find them fast with Yahoo! Search. http://tools.search.yahoo.com/newsearch/category.php?category=shopping
Re: DHCP client failure with cable modem
On Feb 22, 2008, at 5:32 PM, David Murphy wrote: PS: another piece of info I left out is that my modem is a Motorola Surfboard SB5120, and my cable ISP is Charter. Does charter require PPPoE?
Re: DHCP client failure with cable modem
On Fri, Feb 22, 2008 at 8:32 PM, David Murphy [EMAIL PROTECTED] wrote: As stated I've demonstrated that the modem is happy to work with either the cheapo router or directly with my desktop, and I verified that it sees them with separate hardware addresses. So it's not hung up on one in particular. The real questions is what happens when your openbsd box is attached to the cheapo router - does it pull an address from the cheapo router? If it does, then then issue is upstream. If it doesn't, then it is your openbsd box. -- http://www.glumbert.com/media/shift http://www.youtube.com/watch?v=tGvHNNOLnCk This officer's men seem to follow him merely out of idle curiosity. -- Sandhurst officer cadet evaluation. Securing an environment of Windows platforms from abuse - external or internal - is akin to trying to install sprinklers in a fireworks factory where smoking on the job is permitted. -- Gene Spafford learn french: http://www.youtube.com/watch?v=j1G-3laJJP0feature=related
Re: DHCP client failure with cable modem
--- johan beisser [EMAIL PROTECTED] wrote: On Feb 22, 2008, at 5:32 PM, David Murphy wrote: PS: another piece of info I left out is that my modem is a Motorola Surfboard SB5120, and my cable ISP is Charter. Does charter require PPPoE? No. I don't recall having to do any PPPoE setup when I initially set up the cheapo router, and I definitely didn't do anything like that with my desktop when I plugged it in. --- Predrag Punosevac [EMAIL PROTECTED] wrote: Forgive me but I will ask a very stupid question. Did you use a cross over cable when you connected the OpenBSD box to switch. Your switch should also have a button for one of its LAN plugs so that when you use regular CAT 5 cable it reverse the stream so that you do not need to buy cross over cable. No, no crossover cables were used. The problem isn't on the switch side, though... the switch is on the internal side of the router, which is working fine. The problem is between the router's external interface and the modem. If the hardware set up is OK you will really need to give much more info about the network and OpenBSD box in particular so that people can trouble shut. I'd be happy to provide any information requested. I'm quite new to *BSD, but I'm pretty well-versed in Linux, so tell me what you need, and I'll find it. If you need more information about the box than what I gave at the end of my first post, let me know. Thanks... David Murphy Looking for last minute shopping deals? Find them fast with Yahoo! Search. http://tools.search.yahoo.com/newsearch/category.php?category=shopping
Re: DHCP client failure with cable modem
On Feb 22, 2008, at 8:19 PM, David Murphy wrote: I'd be happy to provide any information requested. I'm quite new to *BSD, but I'm pretty well-versed in Linux, so tell me what you need, and I'll find it. If you need more information about the box than what I gave at the end of my first post, let me know. Ok. When you initially plug in the modem side interface, what does it see? Do a basic tcpdump, and watch the traffic for the dhcp assignment. Secondly, could you forward your pf.conf?
Re: DHCP client failure with cable modem
--- johan beisser [EMAIL PROTECTED] wrote: Ok. When you initially plug in the modem side interface, what does it see? Do a basic tcpdump, and watch the traffic for the dhcp assignment. Secondly, could you forward your pf.conf? Well now I'm *really* baffled. I read the manpage for tcpdump, got all set to capture the interface when I plugged in and when I did a netstart... and the darn thing just decided to work. I made no changes to the setup since my last set of failed attempts, and I didn't do anything I haven't tried twice already. ...? Ugh. I've definitely looked at this enough tonight, but tomorrow I'm gonna do some powerdowns and powerups and see if there's any sort of consistency now. Thanks for talking me through it anyway, folks. David Murphy Never miss a thing. Make Yahoo your home page. http://www.yahoo.com/r/hs
