C7000 Can not change LAN IP to 192.168.100.___

[tekman101101]

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)

[tekman101101]

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]

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]

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???

[DarrenM]

What I am saying is that Ip could be in use by the modem and heres a screenshot of when you go to that address and it brings up power levels and SNR for a modem.

DarrenM

[tekman101101]

Ummmmm ..... Darren ..... I am not even going to take the time to type out what is wrong with your post ..... I will however suggest that you take some basic computer network classes ..... sorry ..... but if you take the time to understand what you are actually doing when you type an I.P. (Internet Protocol) address into a web browser you will understand why you ended up at that page you mentioned AND you will understand what I am saying.

Good bye ..... "Live long and prosper"

[tekman101101]

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]

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]

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]

Update:

So I just received the following email from Netgear support:

---------------

Dear Valued Customer,

With regards to your recent case opened with NETGEAR, we have not received a response from you. Please note that this case will be closed in 3 days if we do not receive a response from you by then. To continue troubleshooting this matter, please login to my.netgear.com and update your case (for tickets opened online) or contact us by phone. The expert currently handling this case will typically respond to your message within one business day.

Thanks,
NETGEAR Support

----------

To which I made the following response:

----------

I just received an email from you guys (see below) stating that my case will be closed if you do not hear from me!!!

What the HECK?

As per your previous response to me...... I am still waiting from you guys for a resolution to this confirmed flaw with your product.

Will you please either:

A) (Preferably) Solve my issue.

OR

B) Make sure that my case does NOT automatically close until it IS solved.....

PLEASE?

Thanks in advance.

(It's a good thing I do NOT cuss..... unlike most people now a days)

--------- copy of the email that I just received-------

Dear Valued Customer,

With regards to your recent case opened with NETGEAR, we have not received a response from you. Please note that this case will be closed in 3 days if we do not receive a response from you by then. To continue troubleshooting this matter, please login to my.netgear.com and update your case (for tickets opened online) or contact us by phone. The expert currently handling this case will typically respond to your message within one business day.

Thanks,
NETGEAR Support

--------------

The fun never ends!

Stay tuned..... "same Bat station..... same Bat time" (lol)

[rastajaguares]

hi tekman

I actually have the exact same issue as you, I bumped into this becuase I want to use this in conjunction to the CM1000 cable modem, unfortuantelly that device has the 192.168.100.x subnet hardcoded, so I am hoping that netgear can figure this out.

feel free to refer my case to your support rep 28582534 as this seems to be a flaw on the kernel

one thing that I notice, and you may wanna test this yourself, even of your router is configured to say 192.168.0.1, try to browse to 192.168.100.1, in my case that takes me to the router web interface just like .0.1, I think this is the root cause of the issue, now would be up to netgear to tell us why, which I am starting to thing may not happen

best

[tekman101101]

Hello rastajaguares,

I'm just guessing here but .... English is not your primary language, right? (smile)

Anyway .... And first off ..... What I am pretty sure you meant to say was "gateway", "modem" or "router" INSTEAD of "kernel". Because a "kernel" is the central part of an operating system. It manages the tasks of the computer and the hardware - most notably memory and CPU time.

And .... This FLAW HAS been duplicated by the Netgear support personal already .... I'm just waiting for Netgear to figure out a solution. I just hope that no one at Netgear lost their job because they told me the truth?? So, there is no real need for me to refer to your case number ..... but thanks for the offer. Anyway .... I am positive that many other people have this same issue.

I am trying to interpret your last paragraph ......

OK .... I see what you are saying ....

WOW ..... so, no matter what IP address you assign to this C7000 you can always get to the main GUI page inside this model by going to 192.168.100.1 .... 

That is NOT supposed to happen!

That's GREAT that you noticed that .... It looks as though the engineer that designed this C7000 model incorrectly reserved every IP address between 192.168.100.1 through 192.168.100.254. But I am just guessing on that. (Admittedly I did NOT try every one of those possibilities ..... at $90 per hour ...... I do not have that much time to waste ...... AND I have already wasted WAY TOO much time on this KNOWN FLAW with this Netgear product).

But at the VERY LEAST ....... you have found that this C7000 model has additional problems.

As I said earlier ..... I hope that this issue can be resolved by a firmware update. If not ....... Netgear needs to exchange my flawed C7000 for a comparable model that does NOT have this limitation.

[PFY]

Hi, I’ve just started taking some basic computing/networking classes and your post intrigued me. I sort of understand (but really don’t) what you are saying.

Two things pop into my mind. Firstly could you explain to me why you haven’t tried using IP addresses above .254 - maybe one of them would work for you?

It sure seems like if you have spent hours on this problem maybe it would have been quicker to pick IP addresses in a different range other than 192.168.100.___ ?

Hope you’ve found the answer to your problem!

Best wishes!

[tekman101101]

To answer your question PFY....... That is because these type of cable modem/routers only have the ability to assign UP TO a total of 255 addresses which is standard for all these type of devices.

[tekman101101]

So here is the bottom line:

But the bigger issue is .... AND major drawback with at least this model Netgear cable modem/router (C7000) is that the engineers at Netgear decided to intentionally allocate ALL the addresses that start with the octet of 192.168.100.xxx to some other purpose which completely blocks them from being used at all by the end user.

It is a common practice for businesses to use 192.168.100.xxx as the IP octet for there static networks....... just like 192.168.1.xxx is usually used for Home based networks. This is not written in stone it just seems to be a common practice.... having supported hundreds of businesses over the years.

Other brand cable modem/routers do NOT design there devices so that 192.168.100.xxx are not available to the end user.

I sold this really nice C7000 on Craigslist for just a small loss and purchased a Linksys model which allowed me to use it on this business domain which has ALL of its devices using static IP’s starting with 192.168.100.xxx.

Up until this point I REALLY, REALLY liked Netgear devices.... they always worked (ie no flaws out of the box), are VERY user friendly and most importantly very compatible with other network equipment.

But thanks to this recent design change by Netgear I am going to have to rethink my preferences when purchasing cable modem/routers.

Interestingly enough SEVERAL of the “experts” at Netgear that replied to my support request knew NOTHING of this limitation with there cable modem/routers. If you go back to the very beginning of my post here .... you will see just how many “experts” at Netgear replied to my post and suggested possible “fixes” for something that can not be changed because it was intentionally designed that way by the engineers at Netgear.

[vkdelta]

@tekman101101

it 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]

> So here is the bottom line:
> [...]

   I know nothing, but it sounds to me as if the C7000 effectively
comprises a cable modem which has a LAN subnet of 192.168.100.0/24, and
a LAN interface address of 192.168.100.x, and a router whose WAN
interface (address 192.168.100.y, where y != x) is connected to the
modem's LAN interface.

   Because the (real, internal) router has a WAN interface on a
192.168.100.0/24 subnet, it can't allow a LAN address which uses that
same subnet.  Hence:

> "FAILURE Invalid data. LAN IP address overlapped"

The overlap would be between the proposed 192.168.100.0/24 LAN subnet
and the internal (hidden) 192.168.100.0/24 WAN subnet.

   I don't know if it's true, but it would seem to explain the observed
behavior.  It might also explain why pointing a web browser at
192.168.100.1 leads to the usual built-in web server which is normally
accessed at the router's LAN address.  (y = 1?)

> What I am saying is that Ip could be in use by the modem [...]

   Exactly.  Of course, documenting that restriction might have been
more helpful than not documenting it.  (And might have saved us all from
a series of rants.)

    To me, this sounds like a relatively clever (although inelegant)
engineering decision, allowing the reuse of some existing modem
hardware/firmware.  If the firmware allowed the user to change the
internal (hidden) subnet, or if the firmware could do it automatically,
then this limitation could be overcome.  I'd guess that the number of
users who actually care is probably too small to justify the effort.
But what do I know?

[vkdelta]

@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 modem

WAN-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.

[antinode]

> C7000 is rather a homogenous product and not two seperate products
> inside.

   Ah, well.  It was a good hypothesis while it lasted.  Thanks for the
(real) explanation.

[tekman101101]

I am not going to waste any more of my valuable time on this issue that turns out to be because of a poorly designed Netgear cable modem/router!

If this is so widely known as you are trying to say....... why didn’t several Netgear employees .... so called “experts” know about it? I submitted a support request to Netgear about this issue and at least SIX different “experts” tried to solve it BEFORE bumping it up to the next level of support.

As I mentioned in my previous reply I sold this unused Netgear C7000 on Craigslist for just a small loss.

AND ....I was able to purchase and use an Actiontec (sorry I mistakenly said it was a Linksys brand earlier) Cable modem router and I had NO TROUBLE setting it’s internal IP address to 192.168.100.254

I forget exactly what model Actiontec I purchased but I will get it the next time I am at this business and try to post it here.

I support hundreds of residential customers and dozens of small businesses here in the Portland, Oregon area...... and (as I mentioned previously) it is a common practice for businesses to use the first three octet’s of 192.168.100.xxx for there network devices AND to set up all there devices with static IP addresses.

I am certainly NOT going to change the static IP addresses on well over FIFTY network devices because Netgear has made a poor decision to block off all of the addresses where the first three octet’s are 192.168.100.xxx

I am VERY disappointed with Netgear right now and I am going to reconsider what brand network devices I purchase AND recommend to my customers going forward!

[K4scx]

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.”

[vkdelta]

sure. Please post a model of the "actiontec" "Cable Modem Router" which you purchased. We would be happy to check it. 

as far I know, I have not seen actiontec manufacturing "Cable Modem Router" devices. It is not on their website (https://www.actiontec.com/wifi-routers-gateways/).