DHCP over bridge

thinkninja · 03-01-2005, 03:57 AM

I'm having a bit of a hard time getting my Debian desktop to grab an IP over my OpenBSD bridge. The strange thing is it works fine for my hardphone and FreeBSD box.

My network looks like:

Code:

Netgear ADSL router -- OpenBSD box -- Netgear switch -- FreeBSD box
         |                                        \
    Debian box                                   VOIP hardphone

And all I want to do is connect the Debian box to the switch. My networking knowledge is very poor

Here's a snippet of the tcpdump I made on the OpenBSD box when I last tried it:

Quote:

09:13:05.763923 802.1d config root=8000.0:9:5b:d5:9f:84 rootcost=0x0 bridge=8000.0:9:5b:d5:9f:84 port=0x8001 age=0/0 max=6/0 hello=2/0 fwdelay=0/0
09:13:05.865324 stone.my.domain.39783 > 192.168.0.1.domain: 45600+ PTR? 209.5.174.82.in-addr.arpa. (43)
09:13:05.902830 192.168.0.1.domain > stone.my.domain.39783: 45600 1/2/2 (163) (DF)
09:13:05.904525 stone.my.domain.43938 > 192.168.0.1.domain: 37724+ PTR? 63.57.111.80.in-addr.arpa. (43)
09:13:05.940960 192.168.0.1.domain > stone.my.domain.43938: 37724 1/4/3 (223) (DF)
09:13:05.942477 stone.my.domain.34751 > 192.168.0.1.domain: 63517+[|domain]
09:13:06.484245 h47n1fls305o1100.telia.com.6881 > fire.my.domain.34338: P 2403120453:2403120475(22) ack 2507407944 win 25196 (DF)
09:13:06.780737 ip68-105-230-84.lu.dl.cox.net.6882 > fire.my.domain.51311: P 0:18(18) ack 1 win 63704 (DF)
09:13:07.296549 82-32-10-131.cable.ubr02.azte.blueyonder.co.uk.6881 > fire.my.domain.33681: P 2687584054:2687584067(13) ack 1611060907 win 16721 (DF)
09:13:07.410680 203-217-36-19.dyn.iinet.net.au.6881 > fire.my.domain.52658: P 1098425823:1098425827(4) ack 1491519211 win 64513 (DF)
09:13:07.573976 DSL217-132-37-147.bb.netvision.net.il.6881 > fire.my.domain.35444: P 3380728187:3380728196(9) ack 1556668778 win 65053 (DF)
09:13:07.771827 802.1d config root=8000.0:9:5b:d5:9f:84 rootcost=0x0 bridge=8000.0:9:5b:d5:9f:84 port=0x8001 age=0/0 max=6/0 hello=2/0 fwdelay=0/0
09:13:07.790521 S010600e0290e4b6b.vc.shawcable.net.7881 > fire.my.domain.33240: . 2994822768:2994824186(1418) ack 2542523223 win 16815 (DF)
09:13:07.792107 82-148-208-93.fiber.unet.nl.6981 > fire.my.domain.41558: P 0:4(4) ack 1 win 64627 (DF)
09:13:07.897945 26-106.lctv-ubr2-blk1.cablelynx.com.6881 > fire.my.domain.57941: P 0:9(9) ack 1 win 62894 (DF)
09:13:08.168901 cpe-70-112-35-202.austin.res.rr.com.6881 > fire.my.domain.39402: P 430191210:430191227(17) ack 3129401913 win 65535 (DF)
09:13:08.205390 61-23-142-21.rev.home.ne.jp.4748 > fire.my.domain.6881: P 0:4(4) ack 1 win 64895 (DF)
09:13:08.225373 0.0.0.0.bootpc > 255.255.255.255.bootps: xid:0x8433e629 [|bootp] [tos 0x10]
09:13:08.227044 192.168.0.1.bootps > fire.my.domain.bootpc: xid:0x8433e629 Y:fire.my.domain file ""[|bootp]
09:13:08.913596 192.168.0.10.sip > sh-ppc.gradwell.net.5082: udp 452
09:13:09.779774 802.1d config root=8000.0:9:5b:d5:9f:84 rootcost=0x0 bridge=8000.0:9:5b:d5:9f:84 port=0x8001 age=0/0 max=6/0 hello=2/0 fwdelay=0/0
09:13:09.831853 dsl027-181-173.sfo1.dsl.speakeasy.net.6882 > fire.my.domain.41041: P 165926730:165926734(4) ack 1670527166 win 34032 (DF)
09:13:09.837648 251.80-203-115.nextgentel.com.6346 > fire.my.domain.42278: P 0:12(12) ack 1 win 63889 (DF)
09:13:09.967527 CPE-141-168-34-75.nsw.bigpond.net.au.47284 > fire.my.domain.48424: P 243081566:243081588(22) ack 1745181711 win 63974 (DF)
09:13:10.021151 192.168.0.1.domain > stone.my.domain.34751: 63517 ServFail-[|domain] (DF)
09:13:10.022995 stone.my.domain.25504 > 192.168.0.1.domain: 36709+ PTR? 84.230.105.68.in-addr.arpa. (44)
09:13:10.175118 192.168.0.1.domain > stone.my.domain.25504: 36709 1/3/3 (196) (DF)

Or I can post `grep fire /var/badbridge` (long).

Further, I can ping the hardphone and FreeBSD box from the Deb. box even though the router and the OpenBSD box are unreachable.

It's probably something trivial but this is driving me crazy.

Edit: Fixed. dhclient sucks, use dhcp3-client :/

fr_laz · 03-02-2005, 01:01 PM

Hi,

Does your router act as a switch or as a real router ?

routers don't forward dhcp request from an interface to another (they do not forward broadcast packets : if they did so, there would be a hell lot of noise on WAN - and Ineternet).

With most of advanced routers, you can specify the IP of your dhcp server, so that dhcp request are forwarded to the right host. I don't know if the netgear box you have can do it (on cisco devices it's named helper-address).

BUT : some home routers have 4 or more ethernet adapters that act like a switch...