[Discuss] selecting a subnet

[bill at horne.net (Bill Horne)]

On 9/10/2014 4:04 PM, Stephen Adler wrote:
> Guys,
>
> I'm setting up a small network at work behind my own firewall. Typically
> I would use a 192.168.1.0/24 network but I'm afraid the IT people at
> work have used that for something in my work LAN environment. Is there a
> way of probing the work LAN network to ensure that what ever IP address
> I select for my network doesn't get tangled up with one on the corporate
> LAN? Or is it best to just choose one and hope for the best?

Steve,

If by "Firewall" you mean Network Address Translation-enabled wired-only 
router, then it's a non issue. You plug the "WAN" port into your 
corporate network and set it for DHCP (or whatever fixed address your IT 
guys assigned to the port).  The router will translate whatever 
"detached" IP range you choose, e.g., 192.168.255.0/24, and you'll be in 
business.

If you're router is /also/ a WiFi hotspot, then you'll be OK so long as 
your IT guys don't come with pitchforks: hotspots automagically 
associate with end-user devices, and the addresses won't be in conflict 
with each other unless you choose the same "SSID" that your company uses 
(actually, not even then, but I won't quibble).

However, as others have pointed out, it's best to involve your company 
IT staff, so that they can assign a valid IP which is isolated from any 
internal networks that those using your router should not see.

Bill Horne

-- 
E. William Horne
William Warren Consulting
339-364-8487