Hey All, So, I bought this REALLY nice C7000 Nighthawk cable modem router and I want to use it instead of the old cheap Comcast cable modem here. I have "upgraded" dozens and dozens of the cheap Comcast cable modem routers over the years with no problem. I have already configured the WAN side and it sees the web just fine. I have also configured the wireless just the way I want it. Final step was to change the LAN IP in this cable modem/router to 192.168.100.254 (I can change the last octet to anyone that is not currently being used on this network). But I need the first three octets to be 192.168.100. But EVERY TIME I change the LAN IP from the default of 192.168.0.1 to the IP of 192.168.100. ____ I get an error message of: "FAILURE Invalid data. LAN IP address overlapped" Now, before someone suggests it is because of DHCP routing I have both tried disabling DHCP AND leaving it on but set to a different range FAR away from the address that I use for the IP Address. Example: If I set the LAN IP to 192.168.100.254...... I set the DHCP range to 192.168.100. 70 TO 192.168.100.75 WITH NO CHANGE.... same error message. And I have tried several different combinations..... no help.I AM able to change the IP address to another IP like 192.168.1.1 etc. just fine. but NOT to the IP address that I absolutely positively need. There does not appear to be anything else in this cable modem/router that is using the IP of 192.168.100. ____ so, there is NO overlap. Not even the guest wireless as some other posts have suggested. I have tried everything I can think of with no success. But perhaps I have missed something. So, if anyone has a fix I would greatly appreciate it. Thanks in advance (smile)

You don’t seem to know the difference between “there” and “their,” so I don’t think you should make comments about his “primary language.”

tekman101101it is NOT a flaw. It is by design. It is as per DOCSIS specification. Please review if you have time.you have so many private subnets (as per RFC1918) to use and I am not sure why you are just stuck with 192.168.100.x. Also every "Cable Modem Router" should have the same design as well. you can purchase a non-NTGR modem and report back here if you see different behaviour. **FROM DOCSIS 3.0 OSSI Spec**The CM MUST support 192.168.100.1, as the well-known diagnostic IP address accessible only from the CMCI interfaces. The CM MUST support the well-known diagnostic IP address, 192.168.100.1, on all physical interfaces associated with the CMCI. **** you can download the specification from CableLabs website. It is free. you could cross-reference this post on the DSLReports Forum where lot of esteemed Cable Community members post and they can provide you further details as well (https://www.dslreports.com/forum/comcast)

antinode C7000 is rather a homogenous product and not two seperate products inside. I am going to seperate different IP address into different stacks. exact terminology may be different but more on these lines. CM - Stack = this is Management IPv4/IPv6 address which ISP such as Comcast uses to manage the Cable modemWAN-Stack = This is ONLY on Cable Modem Routers/Gateways. this is true WAN address where all the traffic is NAT'ed. for most ISPs, you will get Public IPv4/IPv6 address here. LAN - Stack = this is your private address where the traffic is NAT'ed. Typically 192.168.0.x Private - Stack = This is the 192.168.100.1 stack which is listening for LAN side HTTP for diagnostics and GUI access. This is there on both Cable modems and Cable Modem Routers/Gateways. This interface does NOT NAT traffic.

WOW.... 240 (now 275) views and not even 1 suggestion so far?? I just verified that I WAS able to set the LAN IP on an older LINKSYS cable modem router (that I borrowed) with this Comcast cable connection to the 192.168.100. ____ that I need it to be. I am thinking this is a flaw in this Netgear model router. Of course, NO ONE will EVER will admit that. The only questions are:1) Is this a flaw that can be corrected by a firmware update?2) Will Netgear feel that it is important enough to spend the money to have their engineers write a firmware update that DOES correct it?3) If the answer is "no" (which is most likely) to number 1 or 2 above...... can I get a FREE replacement that actually DOES allow me to change the LAN IP address to what I need it to be? Annnnnnnnd the answer to that is most likely "no" as well. And that explains why there are no replies to my original post! YEA..... I just wasted $212 thanks to Netgear..... YEA!

Hello tekman101101 I know sometimes with cable modems the cable modem side of the unit will use 192.168.100.1 to access the cable power levels and down and upstream. Have you tried to see if that will pull up with that ip address? DarrenM

C7000 Can not change LAN IP to 192.168.100.___

21 Replies

tekman101101
Aspirant
Jun 14, 2017
Now..... to actually make some progress.....

I just want to give everyone an update on this issue (smile)....

The support people at Netgear have duplicated this flaw with model C7000 on there end........ and they have "advanced" the case to the next support level ..... in there words they have "already reported this to the higher trier of support".

So...... it appears I was wrong..... Netgear customer support WAS honest and they did admit that this is a valid flaw.

Now..... hopefully this issue can be corrected by a firmware update.

(Note: As an A Plus certified, MCSE who has been supporting computers since 1988 when I was top of my class of fifteen students at college ...... I almost NEVER need to contact "Customer Support". Just usually for warranty replacements or to reset one of my customers passwords. Ninety-eight percent of the time I know more then the support person that I am communicating with. Usually they assume the person they are talking with is wrong and they do everything they can to end the support session......I mean how could the product they support be anything but perfect! I don't really blame them ..... having done support for Hewlett Packard, 3 Com, Macintosh, etc over the years I understand at how ridiculous some of the support requests are. Anyway.... it is just reassuring to experience some FANTASTIC and honest customer support at Netgear.)
- rastajaguares
  Aspirant
  Jun 18, 2017
  hey I have the exact same problem as you, unfortunately in my case support says they can change the address with no problem, have you heard anything different on your side?
  - tekman101101
    Aspirant
    Jun 19, 2017
    Hello "rastajaguares". (That's quite a nickname you have there)
    
    Anyway........
    
    I am still waiting for Netgear to resolve this confirmed flaw with there C7000 product.
    
    I was actually amazed (but glad) that they told me the truth. Now I do not know your particular situation (and this is just my opinion here) but do you REALLY think that you WERE told the truth? Once again..... I have no idea about your case .... so please do NOT quote me.
    
    I will however post updates here just as soon as I have them.
tekman101101
Aspirant
Jun 05, 2017
WOW.... 240 (now 275) views and not even 1 suggestion so far??

I just verified that I WAS able to set the LAN IP on an older LINKSYS cable modem router (that I borrowed) with this Comcast cable connection to the 192.168.100. ____ that I need it to be.

I am thinking this is a flaw in this Netgear model router. Of course, NO ONE will EVER will admit that.

The only questions are:
1) Is this a flaw that can be corrected by a firmware update?
2) Will Netgear feel that it is important enough to spend the money to have their engineers write a firmware update that DOES correct it?
3) If the answer is "no" (which is most likely) to number 1 or 2 above...... can I get a FREE replacement that actually DOES allow me to change the LAN IP address to what I need it to be? Annnnnnnnd the answer to that is most likely "no" as well.

And that explains why there are no replies to my original post!

YEA..... I just wasted $212 thanks to Netgear..... YEA!
- DarrenM
  Sr. NETGEAR Moderator
  Jun 07, 2017
  Hello tekman101101
  
  I know sometimes with cable modems the cable modem side of the unit will use 192.168.100.1 to access the cable power levels and down and upstream. Have you tried to see if that will pull up with that ip address?
  
  DarrenM
  - tekman101101
    Aspirant
    Jun 08, 2017
    Hello Darren,
    
    Thank you for at least taking the time to try …… I suppose.
    
    I’m sorry but your English grammar is terrible....... I THINK what you are trying to say is that YOU have seen some cable modems use the IP address of 192.168.100.1 to access or report the "power levels"??? Beside the fact that I have NEVER seen that in ANY cable modem after having configured and setup literally dozens and dozens of cable modems myself...... If that was even a remote possibility.... why would the Netgear support technicians just suggest to me that I try that very specific IP address of 192.168.100.1 to see if it cures the error message?
    
    (Please see the reply from NETGEAR below)
    
    But also…… your suggestion is incorrect for several other reasons…. But I do not feel like typing them all up. And at $90 per hour I need to get to the REAL solution as quickly as possible.
    
    ------------------------------------------------- The latest reply from Netgear technical support: --------------------
    
    Response from NETGEAR
    Hi, Will,
    
    Thank you for your response!
    
    With regard to the case, can you try to set the LAN IP Address to 192.168.100.1, mark Use Gateway as DHCP server and then click apply button?
    
    See if you get the same error message or not.
    
    If the issue still persist, can you try to factory reset the modem router and then try to change the LAN Setup again to your preferred LAN IP settings?
    
    Here are the steps to reset the modem router.
    Note: The modem router should be powered on while doing the reset.
    
    a. Please push the reset button (using a small pin or paper clip) at the back of the modem router and release after 30 seconds.
    b. Unplug the power adapter for 10 seconds and then plug it back in.
    
    **This will make all the settings of the modem router back to default.
    
    If the information provided did not help in resolving your issues, please log into https://my.netgear.com to respond to this email.
    
    Thank you for choosing NETGEAR.
    
    Regards,
    ------------------------------------------------------
    
    Well……. Both you and Netgear are batting zero…… as their suggestion did NOT help and yours does not even come close……. but I suppose it’s the effort that counts???

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C7000 Can not change LAN IP to 192.168.100.___