He seemed to be talking about changing the lease time in the already negotiated lease file. I wasn't aware you could even configure DHCP clients to ask for a given release interval. I never saw such an option when setting up DHCP client. Tom Veldhouse veldy at veldy.net ----- Original Message ----- From: "Adam Maloney" <adamm at sihope.com> To: <tclug-list at mn-linux.org> Sent: Tuesday, October 03, 2000 10:23 AM Subject: Re: [TCLUG:21970] Should DSL or Cable modem > No, if he tells the client to ask for a lease time of 3 weeks, the client > sends that during the negotiation. The server can reject that lease time > if it's too long with a NACK followed by another OFFER with a more > plausible lease time. > > Maybe I mis-understood what he said though. Did he just change the lease > time in the file that dhcpcd writes with the state information? That's > bad. Really bad. If he changes the lease time there then the server > doesn't know about it. Then you're right, if he sets that to 3 weeks and > the initial lease was for 2 weeks, then after 2 weeks the server will be > expecting a renew that it will never get. It'll assume the client's gone > and put the IP back into the pool. If a new subscriber came along they > could snag up "his" IP legitimately. Then after a week his client will > try to renew the IP and the server will NACK it because it's already been > leased. Not to mention all the problems he'd have with IP conflicts. > > Adam Maloney > Systems Administrator > Sihope Communications > > On Tue, 3 Oct 2000, Thomas T. Veldhouse wrote: > > > Right. But if he changes the lease time to 3 weeks, but the server is > > configured for 2 weeks, there may be a 1 week period where two different > > computers share the same IP address, because somebody else has received the > > IP address, and his computer will not ask to renew the old IP address for > > another week yet. > > > > Tom Veldhouse > > veldy at veldy.net > > > > ----- Original Message ----- > > From: "Adam Maloney" <adamm at sihope.com> > > To: <tclug-list at mn-linux.org> > > Sent: Tuesday, October 03, 2000 9:30 AM > > Subject: Re: [TCLUG:21970] Should DSL or Cable modem > > > > > > > Well if his dhcp client sends a Renew request to the server, the server > > > can reject it. The dhcp client will then just ask for a new IP. As long > > > as he doesn't muck with the client (or bypass it altogether and just > > > statically configure it) he can't cause any trouble. The server can > > > always reject renew requests if the address has already bgeen reassigned. > > > I don't think there's anything he can do to the configuration of the > > > client that could screw anything up, I think he'd have to modify the > > > source. > > > > > > If the IP has already been leased to someone else, and his client asks for > > > that IP (in a renew request) the server will send a NACK back, then an > > > OFFER with a new IP. > > > > > > In any case, by changing the lease time you're probably not helping > > > yourself at all. As soon as the lease ends your client will send a renew > > > request back to the server and you'll get your IP back anyways. The lease > > > time just dictates how long before you have to renew again, but if the > > > server reboots you may be SOL. I believe ISC's stores the lease > > > information in /var somewhere so if the server restarts it'll know who has > > > what leased...but I don't know about whatever DHCP server they're using. > > > If it's Microsoft's it'll probably explode or something... > > > > > > Adam Maloney > > > Systems Administrator > > > Sihope Communications > > > > > > On Tue, 3 Oct 2000, Thomas T. Veldhouse wrote: > > > > > > > Yeah, and that somebody is going to be pissed if they find out that > > somebdoy > > > > is using their IP and causing them to have problems with there cable > > modem. > > > > Most users are not going to know what the problem is and they are simply > > > > going to call MediaOne and complain. If MediaOne then finds this, one > > had > > > > better watch out, because suddenly the support costs are larger than the > > > > profits that they are making off of the trouble causing individual. > > > > > > > > Tom Veldhouse > > > > veldy at veldy.net > > > > > > > > ----- Original Message ----- > > > > From: "Adam Maloney" <adamm at sihope.com> > > > > To: <tclug-list at mn-linux.org> > > > > Sent: Tuesday, October 03, 2000 9:17 AM > > > > Subject: Re: [TCLUG:21970] Should DSL or Cable modem > > > > > > > > > > > > > Well if they ran ISC's DHCPd they can set Max-Lease-Time, which is the > > > > > maximum amount of time a given address will be leased for. That's not > > to > > > > > say that when the lease expires you won't renew and get it again, but > > if > > > > > you don't renew right away someone else will probably get it. > > > > > > > > > > Adam Maloney > > > > > Systems Administrator > > > > > Sihope Communications > > > > > > > > > > On Mon, 2 Oct 2000, Eric F Crist wrote: > > > > > > > > > > > Trust me, it works. I've gotten calls from TW and MediaDumb (aka > > ATT) > > > > and > > > > > > they've not been able to stop it, short of pulling the provision for > > > > your MAC > > > > > > address. > > > > > > > > > > > > But, there are ways around that too. =P > > > > > > > > > > > > On Mon, 02 Oct 2000, you wrote: > > > > > > > > > > > > > > Thats *only* if the other end accepts such bad things. > > > > > > > > > > > > > > AFAIK, you can setup ISC to ignore it. > > > > > > > > > > > > > > * Eric F Crist <ecrist at ardent-hacker.net> [001002 21:37]: > > > > > > > > After a little more research (I had a brain-fart) the file, on a > > > > freebsd = > > > > > > > system > > > > > > > > is /var/db/dhclient.leases > > > > > > > >=20 > > > > > > > > This file is realatively simple and straightfoward. For > > information > > > > on y= > > > > > > > our > > > > > > > > box, type man dhclient.leases > > > > > > > >=20 > > > > > > > > If you have questions or comments, feel free to email me. > > > > > > > >=20 > > > > > > > >=20 > > > > > > > >=20 > > > > > > > > Au Contrair on the static IP. If you're into the computer > > hacking > > > > side of > > > > > > > > things, you can simply change your lease on the IP to never > > expire. > > > > Ther= > > > > > > > e's a > > > > > > > > file located on your hard drive that actually sets your lease. > > This > > > > is > > > > > > > > overwritten at the time of renewal by the DHCP server. I have > > done > > > > this = > > > > > > > myself > > > > > > > > and know others who do it successfully. Maybe not a legit > > static > > > > IP, but= > > > > > > > until > > > > > > > > they find out, who cares?=20 > > > > > > > >=20 > > > > > > > > On Mon, 02 Oct 2000, you wrote: > > > > > > > > > Disadvantages to cable modem (from my point of view) > > > > > > > > > - no static IPs, may be coming soon though > > > > > > > > > - no services on your machine, or you get booted > > > > > > > > >=20 > > > > > > > > > Advantages to cable modem > > > > > > > > > - much faster > > > > > > > > >=20 > > > > > > > > > I got this information from the Time Warner sales rep and the > > tech > > > > rep = > > > > > > > that > > > > > > > > > showed up at my apartment complex trying to get subscribers. > > > > > > > > >=20 > > > > > > > > > --=20 > > > > > > > > > Jon Schewe | http://eggplant.mtu.net/~jpschewe > > > > > > > > > For I am convinced that neither death nor life, neither > > angels=20 > > > > > > > > > nor demons, neither the present nor the future, nor any=20 > > > > > > > > > powers, neither height nor depth, nor anything else in all=20 > > > > > > > > > creation, will be able to separate us from the love of God > > that=20 > > > > > > > > > is in Christ Jesus our Lord. - Romans 8:38-39 > > > > > > > > >=20 > > > > > > > > >=20 > > > > > > > > > > > > > --------------------------------------------------------------------- > > > > > > > > > To unsubscribe, e-mail: tclug-list-unsubscribe at mn-linux.org > > > > > > > > > For additional commands, e-mail: tclug-list-help at mn-linux.org > > > > > > > > --=20 > > > > > > > > Eric F Crist > > > > > > > > System Administrator > > > > > > > > Ardent-Hacker.net > > > > > > > >=20 > > > > > > > > > > > > --------------------------------------------------------------------- > > > > > > > > To unsubscribe, e-mail: tclug-list-unsubscribe at mn-linux.org > > > > > > > > For additional commands, e-mail: tclug-list-help at mn-linux.org > > > > > > > >=20 > > > > > > > > > > > > > > --=20 > > > > > > > Scott Dier <dieman at ringworld.org> #nicnac at efnet=20 > > > > > > > http://www.ringworld.org/ finger:dieman at destiny.ringworld.org > > > > > > > > > > > > > > > > > > > ---------------------------------------- > > > > > > Content-Type: application/pgp-signature; name="unnamed" > > > > > > Content-Transfer-Encoding: 7bit > > > > > > Content-Description: > > > > > > ---------------------------------------- > > > > > > > > > > > > ---------------------------------------- > > > > > > Content-Type: text/plain; name="unnamed" > > > > > > Content-Transfer-Encoding: 7bit > > > > > > Content-Description: > > > > > > ---------------------------------------- > > > > > > > > > > > > -- > > > > > > Eric F Crist > > > > > > System Administrator > > > > > > Ardent-Hacker.net > > > > > > > > > > > > > > --------------------------------------------------------------------- > > > > > > To unsubscribe, e-mail: tclug-list-unsubscribe at mn-linux.org > > > > > > For additional commands, e-mail: tclug-list-help at mn-linux.org > > > > > > > > > > > > > > > > > > > > > > > > > > > --------------------------------------------------------------------- > > > > > To unsubscribe, e-mail: tclug-list-unsubscribe at mn-linux.org > > > > > For additional commands, e-mail: tclug-list-help at mn-linux.org > > > > > > > > > > > > > > > > > > > > > > --------------------------------------------------------------------- > > > > To unsubscribe, e-mail: tclug-list-unsubscribe at mn-linux.org > > > > For additional commands, e-mail: tclug-list-help at mn-linux.org > > > > > > > > > > > > > > > > > --------------------------------------------------------------------- > > > To unsubscribe, e-mail: tclug-list-unsubscribe at mn-linux.org > > > For additional commands, e-mail: tclug-list-help at mn-linux.org > > > > > > > > > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: tclug-list-unsubscribe at mn-linux.org > > For additional commands, e-mail: tclug-list-help at mn-linux.org > > > > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: tclug-list-unsubscribe at mn-linux.org > For additional commands, e-mail: tclug-list-help at mn-linux.org > > --------------------------------------------------------------------- To unsubscribe, e-mail: tclug-list-unsubscribe at mn-linux.org For additional commands, e-mail: tclug-list-help at mn-linux.org