For some time, I've had DSL and used Fixed-IP internally. I moved, no DSL, no cable, no nuthin' but dial-up and flaky cell-phone modem. Ugh. Along comes American Recovery and Reinvestment Act providing funding for making high-speed internet available to those of us in the boonies; no up-front or monthly equipment costs, affordable monthly changes, whoo-boy, that's for me. Installed, works, bada-boom, bada bing.

I have three servers, a network printer and a large format pen plotter that have all happily played together with fixed-IP for years connected via a Linksys BEFSR41 router and CAT-5 or CAT-6 cables and I do not want to screw around with DHCP (and the printer and plotter don't particularly like DHCP in any event). The servers talk to each other with SSH, their names and addresses are in /etc/host and all has been well with the world. DSL connected with PPPoE, HughesNet connects "automatically" to the modem with DHCP. I also have a switch available for additional LAN stuff as needed. Of course I had to do a hard reset of the router when setting up HugheNet (right back to infancy).

I do need to have DHCP enabled in the router for the limited occasions that a Winders thing gets connected to it (not my box, I don't mess with it).

Now, the actual question: is there any setting in the router that will enable fixed-IP, ignore DHCP leases unless the server is running DHCP (like a Winders box) and not bother me with screwy lease addresses that override my fixed-IP addresses? My servers are running Slackware 13.1, all configured with fixed-IP, all configured to "know" each other via /etc/hosts, /etc/resolv.conf has DNS Server address in it (and DHCP is not permitted to overwrite /etc/resolv.conf.

Any helpful advice is appreciated.

Having a DHCP server on your network does not force you to have all dynamic IPs on your network. You can have a DHCP server up and running on your network and still use static IPs where you want.

You want to make sure that the static IPs you use are on the same subnet as the IPs being passed out by your router, but that they are not within the range of IPs that the DHCP server uses.

So, if your router is 192.168.1.1 and its DHCP server uses the range 192.168.1.100 through 192.168.1.254, then you would want to assign static IPs in the range of 192.168.1.2 through 192.168.1.99.

Hope this makes sense and helps.

-z1p

1 members found this post helpful.

Yup, it does make sense and does help, thank you.

That's pretty much what I've always done -- fixed-IP from xxx.xxx.1.2 through xxx.xxx.1.99. At one point the router decided (for whatever reason I do not know) to hand out xxx.xxx.1.100 to a server (running fixed-IP). A puzzlement, but may have had something to do with fiddling around setting up HughesNet, talking directly to the modem, who knows what. I know I need to do the pass-through port addresses for HTTP and SSH and, you know, those really want fixed-IP to not be bothersome.

So, I 'spect I'm good to go as is and thank you.

Thomas

That is an odd one at it is the machine that initiate the IP assignment. Anyway, hopefully all works well. Just as a bit of an aside. Another option is static DHCP assignments. Not sure if you've run across it, but with it you can configure the systems on the network to use DHCP, but at the DHCP server assign specific IP address to specific MAC addresses. This is how I run my network. It allows me to assign specific IPs to systems I want, leave the rest dynamic and I get to administer the IPs at one point (the DHCP server). It also has the advantage that if I swap out the router and the new one defaults to a different subnet, everything still comes online even before I get a chance to assign IPs.

Best of Luck.

-z1p

Interesting. Never thought of doing that (but, as is, stuff is mumbling happily to each other) and may give it try when things cools down a little and I've got time to fiddle.

Thanks for the suggestion.