"Ben Scott" <[EMAIL PROTECTED]> writes: > Well... okay... but it's the *why* that makes me wonder. :) > > I hope it's something interesting, and not just that he's trying to > say that he's been assigned the addresses in the range 10.0.32.0/19 on > the 10.0.0.0/16 network. That would be *so* boring. :)
Well, since you've asked, I'm sure you'll regret it :) I'll try to be as brief and concise, yet clear as possible. It's confusing. We have no internal router. Just a legacy BSD box acting as a firewall. The internal network, for there really is only one, is 10.0.0.0/16. When it was set up, the 10.0.0 space was allocated along CIDR boundaries on the premise that someday we would have a router to separate un-like network traffic. As a result, we have something like this: Address/CIDR block| Function | Address Range Defined ------------------------------------------------------------------------------ 10.0.0/22 | Dev/infrastructure servers | 10.0.0.0 - 10.0.3.255 10.0.4/22 | Mgmt/admin desktops, Mac laptops | 10.0.4.0 - 10.0.7.255 10.0.8/22 | Dev desktops | 10.0.8.0 - 10.0.11.255 10.0.12/24 | Network hardware | 10.0.12.0 - 10.0.12.255 10.0.13/24 | Printers | 10.0.13.0 - 10.0.13.255 10.0.14/24 | MS-OS systems | 10.0.14.0 - 10.0.14.255 10.0.32/19 | Dev lab systems | 10.0.32.0 - 10.0.63.255 This allocates a generous portion of addresses to various uses, and, if need be, subdivide based on /24 boundaries if we wanted to. The 10.0.32/19 is an interesting beast. The systems which live on it have 2 NICs, the primary eth0, which *always* have a 10.0.32/19 based address (currently restricted to 10.0.33/24 for some reason?!), and a secondary eth1 which has a primary address of 10.106.XX.YY where XX.YY are the same as the 10.0.XX.YY, and where XX is currently always 33. i.e. host 10.0.33.124 has an eth1 IP of 10.106.33.124. Here's the *really* confusing part. Every system's eth1 *also* has 10 virtual/alias IPs of 10.[96-105].XX.YY. If you recall, I mentioned not having a router. Have I mentioned that the number of hosts in the 10.33/16 range is somewhere around 300, with another 50-100 being added in the next 2 months? :) Both NICs in all systems are essentially on one ethernet network! At any given time, these hosts can have both eth0 and eth1 up, plus any number of the 10 alias IPs up. We are actually about to cut over to a new network configuration this week. However, as the saying goes, "There's nothing more permanent than a temporary solution." and dev has basically evolved their testing infrastructure to *require* this flat network scheme. I'm currently testing things to make sure "nothing breaks" in the transition. One of the things our product does is look at the list of currently configured interfaces, take the "highest" IP and "add 1" to the network portion to obtain a new IP on a different network, but retaining the host portion of the IP. Basically, there's a multi-host negotiation which takes place and figures out a "back-channel" to communicate over. Since name resolution is not possible either via DNS, /etc/hosts, or other means, the only reliable means any two hosts have of reliably talking to each other is making sure that any given host keeps the same host portion of it's IP address on all networks. Does this help clarify things? Ultimately, the ability to support "network addition" using something wacky like a /19 is entirely my own intellectual curiosity, since in-house everything is on a /16 making it trivial. But it's one of those problems I can neither figure out, nor let go of :) As someone said to me yesterday, "IP addresses were never designed to be manipulated, merely assigned and used!" :) -- Seeya, Paul _______________________________________________ gnhlug-discuss mailing list gnhlug-discuss@mail.gnhlug.org http://mail.gnhlug.org/mailman/listinfo/gnhlug-discuss
