The network at work has two IP ranges (both put in long before my arrival) - 192.168.1.0 and 192.174.1.0. None of the info I've ever seen marks the 192.174.1.0 range as being reserved for private IP addressing, so my question is this - is this range going to cause me any problems any point soon, or should I be okay to leave it alone? I'd sooner leave as is if I can, as I have absolutely no idea how to go about reprogramming our routers. Thanks in advance for any advice that anyone may have.

Well, I did a scan of the whole 192.174.1.0. range and did not get any hits, which is good. However, I would not sleep very well in your position - I think you should plan to change to a non-routable subnet. What kind of routers do you have?

We have two Cisco 2503 routers approximately 100 miles apart connected by a 64k leased line. To complicate matters further the leased line side of one router is 192.170.1.1 and the other is 192.170.1.2. :-(

192.168.x.x is private address range but 192.174.x.x is not. Do you know who your ISP is? You should ask them if you are not sure. And if it works leave it alone, but dont forget about firewall stuff etc to protect your network. --- Athlon64 3200+@2.5Ghz, Zalman 7000Cu, DFI NF3 LanParty 2x512 OCZ EL PC3200 Platinum Rev 2, R9800Pro@XT vga silencer, WD 80GB SATA, SB Audigy, Antec TruePower 380PEC 380W

Winkles, I see your problem. It is beyond me why someone would use routable addresses for the LAN. Honestly, I am not sure exactly what the implications of this are, but I would sure investigate it. It's not good enough to say it is working, so don't bother. These things have a way of coming back to bite you at the most inopportune times.

These IP ranges were all put in long before my employment at the firm, by a 'professional' networking outfit too according to my predecessors. Assuming the board release cash to me I shall be giving the network a major shake up in the not too distant future, and I can play about with IP ranges then. I don't so much mind when my own incompetence comes back to haunt me, but when it's other people's incompetence that is the problem I do feel somewhat peeved. Thanks for your responses all, I really just wanted confirmation of what I already suspected.