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Forum Discussion
tanviper
Nov 24, 2019Aspirant
CM1200 not working with wireless routers
I went from cox's 150 internet service to their gigablast service yesterday. I knew I was going to need a new modem as my old one wasn't 3.1. I purchased the Netgear CM1200 and got it setup. My compu...
tanviper
Nov 24, 2019Aspirant
". Even though the CM1200 has 4 ports, your isp only supplies a single ip address"
I did as you suggested, and it's working now. There's now a new issue. My connected speed dropped by 2/3. I was getting 900 megs testing out to fast.com when my computer was plugged into the CM1200, now that it's going through the AC3500,i'm getting 300. Is there something else I need to look at?
Correct me if I'm wrong (my network know-how is limited here)
1) ISP assigns IP address to you
2) I THOUGHT it was assigned to the cable modem since you have to give the ISP (Cox) the serial number, model #, etc.. off the modem.
3) CM1200 has 4 ports on the back, i THOUGHT the modem assigned an interanl IP to those ports so you can have 4 devices directly connected to your CM1200 without them "grabbing" the ISP assigned IP adddress.
4) What good are the extra 3 ports if I can't plug my computer into them?
5) My CURRENT set up is CM1200 with only 1 thing plugged into it (the AC3500) and then everything plugged into it.
6) I'm also using a smaller DGS 105 switch (it's a unmanaged, 5 port Gigabit switch from linksys) for a few smaller things since my AC3500 doesn't have enough ports in the back (it's using one of the ports on the AC3500 and a few items are plugged into the DGS 105.
7) computer is plugged into the AC3500, not the DSG 105 (just want to be clear)
plemans
Nov 24, 2019Guru - Experienced User
tanviper wrote:". Even though the CM1200 has 4 ports, your isp only supplies a single ip address"
I did as you suggested, and it's working now. There's now a new issue. My connected speed dropped by 2/3. I was getting 900 megs testing out to fast.com before switch all of this, now i'm getting 300. Is there something else I need to look at?----Your router. If you were getting full speeds from the modem with it directly connection and then speeds drop when you go modem----router----pc. The router is what's limiting it. Not sure about the linksys settings but I'd check with linksys as to why their device is slowing things down. Sometimes is qos, parental controls, etc thats slowing speeds.
Correct me if I'm wrong (my network know-how is limited here)
1) ISP assigns IP address to you----Most isp's only assign a single ip address. for consumer connections.
2) i THOUGHT it was assigned to the cable modem since you have to get ISP serial number, model, etc..
3) CM1200 has 4 ports on the back, i THOUGHT the modem assigned an interanl IP to those ports so you can have 4 devices directly connected to your CM1200 without them "grabbing" the ISP assigned IP adddress---Sadly, no it doesn't work this way.
4) What good are the extra 3 ports if I can't plug my computer into them?----not a whole lot if you're ISP doesn't assign multiple IP addresses per account or if you don't have a router that has wan link aggregation. I usually recommend the cm1000 or cm1200 for most home users. they're the same basic modem internally.
5) My CURRENT set up is CM1200 with only 1 thing plugged into it (the AC3500) and then everything plugged into it.---that's how it should be.
6) I'm also using a smaller DGS 105 switch for a few smaller things since my AC3500 doesn't have enough ports in the back (it's using one of the ports on the AC3500 and a few items are plugged into the DGS 105.----correct. It should go modem----router----switch/devices.
- tanviperNov 24, 2019Aspirant
"I usually recommend the cm1000 or cm1200 for most home users. they're the same basic modem internally. "
should I take the Cm1200 back and get the cm 1000 then? There is a price difference and if they are the same with the exception of the ports in the back--which I'm now not using--then is there any advantage to keeping the CM1200 over a CM1000?
- plemansNov 24, 2019Guru - Experienced User
Sorry, I mistyped. I usually recommend the cm1000 or cm1100. I'd look at either of these. The only benefit to going more than the cm1000 is if you plan on using port aggreation or getting speeds >1gig. Some ISP's over provision their modems 20% (not sure about yours) so some like the wan port aggregation for this.
CM1000-single port, gigabit
CM1100-2 port for wan port aggregation. Up to 2gig speeds with wan port aggregation. Or for isp's that supple 2 ip addresses
CM1200-4 port, 2 can be used for wan port aggregation. or for isp's that supply up to 4 ip addresses.
- FURRYe38Nov 25, 2019Guru - Experienced User
I recommend you check out a CM1100, it has just two ports in back, supports LAG if you want that, and 1G connections:
Some get confused by the CM1200 having 4 ports in back which some mistakenly take or having a built in router. Any NetGear CM model modem does not have a built in router, period. ISP WAN IP address will pass thru the modem at such time when a device or router gets fully connected. There is a temp IP address assigned to the device or router. however soon after, the WAN IP addresss from the ISP will engage and be seen on the WAN side of the router or network adapter of the device connected to the modem.
tanviper wrote:"I usually recommend the cm1000 or cm1200 for most home users. they're the same basic modem internally. "
should I take the Cm1200 back and get the cm 1000 then? There is a price difference and if they are the same with the exception of the ports in the back--which I'm now not using--then is there any advantage to keeping the CM1200 over a CM1000?
- JasGr81Feb 02, 2020AspirantI was using a switch but wasn’t getting the speed that I was previously getting so I removed the switch completely and the speeds went back up around 115 Mbps. With the switch I was only getting around 70 Mbps.
- FURRYe38Feb 02, 2020Guru - Experienced User
Is the switch rated for 100Mbps or 1000Mpbs connection rates?
Also the switch should be installed after a router, not between the modem and router.