Date: Thu, 27 Feb 2003 08:40:34 -0600 From: "Brian Henning" <b1henning@hotmail.com> To: "Aaron Burke" <aburke@nullplusone.com>, "freebsd" <freebsd-questions@FreeBSD.ORG> Subject: Re: isp connection woes Message-ID: <OE425xFEjwtEb3IU6WO00010953@hotmail.com> References: <AMEMKJNMFLJCJDLFIEDBCEKLCIAA.aburke@nullplusone.com>
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----- Original Message ----- From: "Aaron Burke" <aburke@nullplusone.com> To: "Brian Henning" <b1henning@hotmail.com> Sent: Wednesday, February 26, 2003 1:36 PM Subject: RE: isp connection woes (snip) > > i now know that i am having problems connecting to my dhcp server. > can you try the following? (after first changing the ip address to > 0.0.0.0? > dhclient <your interface card here> > > Then do an ifconfig and see if you got an address? > > > i am in the process of changing the dhcp code (at line 159 in > > /usr/src/contrib/isc-dhcp/common/packet.c) > > i changed this to 128. Then i am going to rebuild everything. > > i was not able to find out the ip address of the dhcp server that > > my isp uses so > > i hope this solves the problem. any other suggestions? it seems > > odd that i would > > have to make this kind of a change to get dhcp to work.. do i need to add > > anything to my rc.conf to enable dhcp? > Yes, I use interface ed0 to get an internet ip from my ISP. > I use the following: > ifconfig_ed0="DHCP" > > > > > rebuild everything > > ------------------ > > cd /usr/src && make buildworld > > cd /usr/src && make buildkernel > > cd /usr/src && make installkernel > > < reboot into single user mode > > > boot -s > > fsck -p > > mount -a > > cd /usr/src && mergemaster -p > > cd /usr/src && make installworld > > cd /usr/src && mergemaster > > reboot > This is way too much work to solve a dns issue. > I mentioned in a previous message on this thread > that you should be no more than a hop or two from > your dhcp server. And for the benefit of people > that are not aware of how DNS works, here is an > example: (For the record, this is off the top > of my head, I expect several people to see a flaw > in my description, but I am not here to argue about > that). > > Step 1: DHCP Client sends and ethernet broadcast > to the address 255.255.255.255:67 from address > 0.0.0.0:68 . (67=bootps, 68=bootpc) > > Step 2: All DHCP servers (sometimes there are more > than one) respond to the client via a standard > packet. The server knows the MAC address of the > client. Every packet on a local area network has > a unique MAC address. > > Step 3: If the client is happy with the address > it will respond to the server with a request for > the ip that the server proposed. > > Step 4: The server will make a note of this and > approve the connection. It will send a packet > back to the client saying that it has permission > to use the address. > > One thing to note is that ethernet broadcast > packets do not usually leave the network interface. > The default that you mention, 16, is a lot of hops > from the client. And DHCP packets are (not sure on > this) sent as UDP packets. Which are not guarenteed > to get to the destination (period). To think of this > a different way, I can be in New York City from my > location in Oregon in 13 hops. > > > > > Thanks, > > brian > Thats what we are here for. > Hello- Thanks to all who helped me get my bsd machine connected to my isp using dhcp. makeing the TTL change to /usr/src/contrib/isc-dhcp/common/packet.c seemed to fix my problem. i know it seems odd to some of you that I would need more than 16 hops, but apparently the ATTBI network is a little different. Going forward I plan on installing natd and some firewall software. Cheers, brian To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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