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c7100v arp table does not seem to clear with factory reset

Inetwl
Aspirant

c7100v arp table does not seem to clear with factory reset

The Netgear C7100v arp table does not seem to clear with factory reset. The reason that I say this is the following configuration.

 

The Netgear C7100V modem, Firmware Version V2.01.42  goes to the cable company, and the LAN is the interior of the building at IP 192.168.0.1.

A Netgear R6400v2 device should complete the modem/router configuration. The C7100V includes the R6400v2 in its access control list. The R6400v2 IP should be dynamically assigned 192.168.0.2 from the C7100V. 

 

However, the R6400v2 keeps coming dynamically in as 192.168.0.16, outside the current C100V DHCP range of 192.168.0.2 - 192.168.0.5.
When I switch to static assignment, the device gateway is displayed as

  • 192.
  • 168.
  • 0.
  • 3 192.168.0.5

Neither 192.168.0.3 nor 192.168.0.5 exists in the current network configuration, and any device that I can think of that may have had these addresses in its ARP table has had them removed or has had a factory reset.

 

I performed factory resets on both devices, and the same thing happened.

 

My question is, how do I clear the device gateway information from both devices so that the C7100V can dynamically assign a reserved address to the R6400v2? 

Model: C7100V|Nighthawk AC1900 WiFi Cable Modem Router
Message 1 of 6

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Inetwl
Aspirant

Re: c7100v arp table does not seem to clear with factory reset

I exchanged the R6400v2 for another router and got the same strangeness out of the C7100V with respect to the gateway IP address. Apparently, something somewhere thinks that 192.168.0.5 should have been the gateway instead of the "3 192.168.0.5" that it displayed when I was using the R6400v2. However, the C7100V seems to be happy with the new router, so that portion seems to have resolved itself.

 

 

As for the R6400v2, I rebooted it and reset it several times, previous to installing it where the other router was, and it is also behaving.

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Message 5 of 6

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antinode
Guru

Re: c7100v arp table does not seem to clear with factory reset

> The Netgear C7100V modem, [...]

 

   It's normally a modem+router.  Or did you configure it as a modem
only?

 

> [...] A Netgear R6400v2 device should complete the modem/router
> configuration. [...]

 

   Why are you adding an R6400v2 to the "C7100V modem"(+router)?

 

> [...] The C7100V includes the R6400v2 in its access control list.
> [...]

 

   "access control list", or Address Reservations, or what, exactly?

 

> The R6400v2 IP should be dynamically assigned 192.168.0.2 from the
> C7100V.


   Says who?  Why?  When configured as a router, an R6400v2 would have
two IP addresses: LAN and WAN/Internet.  Which one do you mean?

 

      https://en.wikipedia.org/wiki/Internet_Protocol
      https://en.wikipedia.org/wiki/IP_address

 

> [...] the R6400v2 keeps coming dynamically in as 192.168.0.16, [...]

 

   Its WAN/Internet interface?  How, exactly, did you configure that?

 

> When I switch to static assignment, [...]

 

   "switch" _what_?  How, exactly?

 

> [...] the device gateway is displayed as [confused mess]

 

   Where is this "device gateway" "displayed"?  Which "device"?


> [...] how do I clear the device gateway information from both devices
> [...]

 

   What, exactly, does "the device gateway information" mean to you?
What, exactly, are you seeing where, exactly?  At least one of us is
confused.

 

> The Netgear C7100v arp table does not seem to clear with factory
> reset. [...]

 

   General advice: You might have more success if you described
(clearly) the actual problem which you are trying to solve, rather than
asking how to implement some particular "solution" ("clear the ARP
table") which may have little or nothing to do with the actual problem
(whatever it might be).

Message 2 of 6
Inetwl
Aspirant

Re: c7100v arp table does not seem to clear with factory reset

  > It's normally a modem+router.  Or did you configure it as a modem
only?

It is configured with the factory reset, and will route some traffic, but I am calling the C7100V the "modem" and the R6400v2 the "router" for ease of use. The R6400v2 is firmware version V1.0.4.106_10.0.80.

 

 > Why are you adding an R6400v2 to the "C7100V modem"(+router)?

When the R6400v2 connects to the C7100V, it should be assigned 192.168.0.2 because it is the first device attached to the C7100V (except for the device from which I am performing the configuration, which so far has not used any of the IP addresses in question). It should be 192.168.0.2 because I want it that way.

 

  > "access control list", or Address Reservations, or what, exactly?

The R6400v2 is in both the access control list and in the reservation list of the C7100V. The access control list uses the mac address and the reservation list contains both the mac address and the intended IP address.

 

> Says who?  Why?  When configured as a router, an R6400v2 would have
two IP addresses: LAN and WAN/Internet.  Which one do you mean?

When configured as a router, the R6400v2 should have a WAN of 192.168.0.2, as assigned by the C7100V, and a LAN of 192.168.1.1. I can change the LAN later if I want.

 

 > Its WAN/Internet interface?  How, exactly, did you configure that?

The weird numbers are from the R6400v2 Advanced, Setup, Internet Setup screen, in the Internet IP Address section. This section contains two options: 1) Get Dynamically from ISP; 2) Use Static IP Address.

 

 >  Where is this "device gateway" "displayed"?  Which "device"?
The very first time the screen is displayed on the R6400v2, the "Get Dynamically from ISP" option is selected, and three addresses are filled in and greyed out.

The three addresses are: IP Address, IP Subnet Mask, and Gateway IP Address, each of which has 4 boxes.

The first two items are normally formatted, even though the IP address contains 192.168.0.16 (which is your question as well as mine). The Gateway IP address has concatenated an entirely different IP address in the last box, so it reads "3 192.168.0.5" in the fourth box.

>>>This is the device gateway information that should be cleared from either (or both) the C7100 and the R6400v2, by reason of factory reset or whatever keeps it from being the default display when the R6400v2 is being initialized.

 

  > "switch" _what_?  How, exactly?

I tried to use the "Use Static IP Address" option, instead of the dynamic one which was assigned on startup.

 

   General advice: You might have more success if you described
(clearly) the actual problem which you are trying to solve...

The C7100V is the cable modem whose LAN is 192.168.0.1.  I am ok with that.

The R6400v2 is the router whose WAN should be 192.168.0.2 and whose LAN should be 192.168.1.1, when it is factory reset and powered up.  There is a cable between its WAN and the C7100V LAN, so I don't know what is interfering with it to give it an address of 192.168.0.16 and a strange gateway IP address that looks like a left-in from some previous configuration that has survived a factory reset, a reboot, a hard reset, to say the least.

Model: C7100V|Nighthawk AC1900 WiFi Cable Modem Router
Message 3 of 6
antinode
Guru

Re: c7100v arp table does not seem to clear with factory reset

> [...] I am calling the C7100V the "modem" and the R6400v2 the "router"
> for ease of use. [...]

 

   You can call it whatever you want, but, after a settings reset, it
should behave as a modem+router, not a simple modem.

 

> Why are you adding an R6400v2 to the "C7100V modem"(+router)?

 

   Still a mystery.  Were you expecting to use any of the router
functions of the C7100V (wireless, for example), or did you really want
it to act as only a modem, with the R6400v2 as your only router?

 

   For that, visit http://netgear.com/support , put in your model
number, and look for Documentation.  Get the User Manual (at least).
Read.  Look for "Set Up the Modem Router in Bridge Mode".

 

   An alternative one-router arrangement would be to configure the
R6400v2 as a wireless access point.  Look in the R6400v2 User Manual for
"Use the Router as a Wireless Access Point".


> [...] It should be 192.168.0.2 because I want it that way.

 

   Ok with me.  Then you might want to reserve that address for it on
the C7100V.  If you did that, using the right MAC address, then I'd
expect that reservation to work.  If you specified the wrong MAC address
in the reservation, then undesired results would not amaze me.

 

> [...] two IP addresses: LAN and WAN/Internet. [...]

 

   That's true for MAC addresses, too.  I'd expect both to be shown at
ADVANCED > ADVANCED Home on the R6400v2 management web site.

 

> The first two items are normally formatted, [...]

 

   I might need an attached picture to make sense of that.  If you
really do want to cascade two routers (which, I'd suggest, is not a wise
plan), then I'd expect the R6400v2 WAN/Internet interface to be
configured so:


      Address: 192.168.0.2
      Subnet mask: 255.255.255.0
      Gateway: 192.168.0.1

 

That'd be using either DHCP or static parameters.  (Any non-conflicting
parameters, including its defaults, should be ok for its LAN.)

 

> [...] a strange gateway IP address that looks like a left-in from some
> previous configuration that has survived a factory reset, [...]

 

   I can't see it, but that sounds to me like the result of a firmware
defect, or well-scrambled (corrupt) settings.  You pressed the Reset
button long enough to cause obvious/unusual LED activity?  (Define "hard
reset"?)

Message 4 of 6
Inetwl
Aspirant

Re: c7100v arp table does not seem to clear with factory reset

I exchanged the R6400v2 for another router and got the same strangeness out of the C7100V with respect to the gateway IP address. Apparently, something somewhere thinks that 192.168.0.5 should have been the gateway instead of the "3 192.168.0.5" that it displayed when I was using the R6400v2. However, the C7100V seems to be happy with the new router, so that portion seems to have resolved itself.

 

 

As for the R6400v2, I rebooted it and reset it several times, previous to installing it where the other router was, and it is also behaving.

Message 5 of 6

Re: c7100v arp table does not seem to clear with factory reset


@Inetwl wrote:

I exchanged the R6400v2 for another router and got the same strangeness out of the C7100V with respect to the gateway IP address.

As has already been explained, you are connecting two routers. It is nothing to do with strangeness. These tnhings arfe doing what you asked them to do.

 

Two routers on your network can cause headaches. For example, you can end up with local address problems. Among other things, the other router can misdirect addresses that the Netgear router usually handles, such as routerlogin.net or the usual IP address for a router, 192.168.1.1.

This explains some of the other drawbacks.

What is Double NAT? | Answer | NETGEAR Support


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