New nighthawk 1750 with existing C3700 cable modem/router

Question

Looking for the least painful way to make a new R6700v2 nighthawk my new wireless router and DHCP server with an existing C3700 cable modem/wireless combo. My existing DHCP config uses class A numbering (10.x.x.x) and every attemp to manually config to class A network on the nighthawk leads to DHCP being configured to class C (192.x.x.x). It's been awile since I've configured these things and this home networking gear has advanced leaps and bounds. I know it is probably something simple that I'm missing but there is a work from home situation that I can't afford to be down for a day. Any advice would be apreciated!

antinode · Answer

&gt; [...] as for the LAN subnet I would like to keep it the same as I have&gt; existing.&nbsp;&nbsp;&nbsp; So long as your new configuration includes only one router, youshould be able to choose whichever LAN subnet you want.&nbsp; But, no matterto which "class" you think it belongs, if you try to use a subnet maskother than "255.255.255.0" (old "class C"), then I'd expect problems.&nbsp;&gt; Trying to replace the wireless functions of the C3700, [...]&nbsp;&nbsp;&nbsp; C3700 or C3700v2?&nbsp; Look at the product label.&nbsp;&nbsp;&nbsp; Visit http://netgear.com/support , put in your (actual) model number,and look for Documentation.&nbsp; Get the User Manual.&nbsp; Read.&nbsp; Look for atopic like "Change the Router Mode".&nbsp; With "Router Mode: No", theC3700[vX] should act like a modem-only, leaving the R6700v2 as your onlyrouter.&nbsp;&nbsp; The alternative would be to leave the C3700 router section active,and configure the R6700v2 as a wireless access point.&nbsp; Get the R6700v2User Manual.&nbsp; Read.&nbsp; Look for "Use the Router as a WiFi Access PointOnly".&nbsp; That would/could leave the wireless stuff active on bothdevices.&nbsp;&nbsp;&nbsp; Either way, you should be left with one LAN subnet, which should beconfigurable on the active router.

antinode · Answer

&gt; [...] currently my mask is 255.0.0.0. [...]&nbsp;&nbsp;&nbsp; I can't guarantee that that would be fatal, but it's a safe bet thatthese routers were not intended to deal with 16M devices/addresses.(250 seems to be a stretch in some cases.)&nbsp;&gt; [...] this is going to sound like a stupid question [...]&nbsp;&nbsp;&nbsp; Nope.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Kasper Gutman : Well, sir, if I told you... If I told you _half_...&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; you'd call me a liar.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Samuel Spade : No, not even if I thought so.&nbsp;&gt; [...] but if I switch the C3700 out of router mode what local network&gt; IP do I use to access it's configuration?&nbsp;&nbsp;&nbsp; A DOCSIS modem has a special-case address for that: "192.168.100.1".(No bets, but I'd expect it to work even if your computer is not on thatsubnet.)&nbsp; Worst case: Settings reset, and deal with it as a modem+routeragain.&nbsp;&nbsp; (And that's "its configuration".)

antinode · Answer

&gt; [...] make a new R6700v2 nighthawk my new wireless router and DHCP&gt; server with an existing C3700 cable modem/wireless combo. [...]&nbsp;&nbsp;&nbsp; What is thae actual problem which you are trying to solve?&nbsp; Are youinterested in preserving the wireless router functions of the C3700, orare you trying to replace the router section of the C3700 with theR6700v2, or what?&nbsp; Why add the R6700v2?&nbsp; Extended wireless-networkcoverage, or what?&nbsp;&gt; [...] My existing DHCP config uses class A numbering (10.x.x.x) [...]&nbsp;&nbsp;&nbsp; Forget "class A/B/C"; it's a long-obsolete concept.&nbsp; Why do you careabout the LAN subnet?

bsputnam25 · Answer

Trying to replace the wireless functions of the C3700, have had performance issues and several people have suggested the AC1750 for better prformance, as for the LAN subnet I would like to keep it the same as I have existing.&nbsp;

bsputnam25 · Answer

"&nbsp;if you try to use a subnet mask&nbsp;other than "255.255.255.0" (old "class C"), then I'd expect problems."&nbsp;You might have just solved my problems right there, currently my mask is 255.0.0.0. I still want to see if I can get the 1750 running, and I did see the change router mode option in my C3700, I'll give those changes a try. Thanks man!

Forum Discussion

New nighthawk 1750 with existing C3700 cable modem/router

6 Replies