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Change DHCP Ending Address to 192.168.2.*

skhaire14
Aspirant

Change DHCP Ending Address to 192.168.2.*

Hope some one can help me.

 

In the LAN Setup of my router, I have chosen below option

 

Use Router as DHCP Server

 

Starting IP Address  is 192.168.1.2
Ending IP Address   is 192.168.1.254

 

I need to change DHCP Ending Address to 192.168.2.254. But upto 192.168.1 is greyed out. See attachement.

Model: R7800|Nighthawk X4S AC2600 Wifi Router
Message 1 of 8

Accepted Solutions
schumaku
Guru

Re: Change DHCP Ending Address to 192.168.2.*

Leaving alone the Netgear design decision for supporting /24 IP subnets only on the consumer (and some other devices): When I see a 255.0.0.0 subnet and then ....

 


@skhaire14 wrote:

I need Private IP and Public IP in two different subnets and they need to be able to communicate with each other

 

Here is my setup would look like:

 

Node 1 / Server A - Public IP - 192.168.1.101  Private IP - 192.168.2.101

Node 2 / Server B - Public IP - 192.168.1.102  Private IP - 192.168.2.102

 

So I need to be able to communicate using my router any address range between 192.168.1.2 to 192.168.2.254.

If you want two subnets, you need either two physically independent networks, or two VLANs, or the one network you have plus a VM internal network for private VM communication purely in software on the host - ll these making up two dedicated broadcast domains. On each of these two networks, you configure an IP subnet each, say 192.168.1.0/24 and 192.168.2.0/24. On each network, you have a DHCP, as (to keep it simple) DHCP can cover only one broadcast domain, and one IPv4 subnet.

 

The communication between the two IPv4 subnets must be done on a router with two interfaces, one in the .1.0 network, one in the .2.0 network.

 

With a 255.0.0.0 subnet, all addresses from 192.0.0.0 - 192.255.255.255 are in the same subnet - and can obliviously communicate as-is - and I assume the router will allow the communication. It does just not allow issuing DHCP addresses beyond of the 192.168.1.x address range. And I don't know if these consumer routers are able to handle NAT in this huge scope.

Said that: These consumer routers only support one (assumingly small) IP subnet and broadcast domain.

View solution in original post

Message 6 of 8

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antinode
Guru

Re: Change DHCP Ending Address to 192.168.2.*

> I need [...]

 

   Why, exactly?  What is the actual problem which you are trying to
solve?

 

> [...] to change DHCP Ending Address to 192.168.2.254. But upto
> 192.168.1 is greyed out. See attachement.

 

   Change the LAN TCPIP/IP Setup : IP Address (and "Apply") first?
It'll still be grayed out, but the gray part should say "192.168.2".

 

   You can't run the DHCP server in these things on a different subnet
from the router itself.

Message 2 of 8
labatt
Mentor

Re: Change DHCP Ending Address to 192.168.2.*

What are you doing that would require more then 252 addresses? Router is not going to handle that number of clients I would guess. Netgear says 32 clients per wifi channel.  

Message 3 of 8
antinode
Guru

Re: Change DHCP Ending Address to 192.168.2.*

> What are you doing that would require more then 252 addresses? [...]

 

   "252"?  (256 less one for ".0", less one for ".1", less one for
".255", less one for what?)

 

> [...] Netgear says 32 clients per wifi channel. [...]

 

   Not all client devices are wireless, but, even so, ...

 


   Ah.  I missed the "255.0.0.0" subnet.  I doubt that you can use
anything wider than a "/24" subnet on these routers.  Especially nothing
close to "/8".

 

   And you certainly could expect trouble when using the "192.0.0.0/8"
subnet, which is what you've specified there.  Plenty of real public
addresses in that range.

 

>    Why, exactly?  What is the actual problem which you are trying to
> solve?


   Those questions still apply.

Message 4 of 8
skhaire14
Aspirant

Re: Change DHCP Ending Address to 192.168.2.*

Thanks for the reply. 

 

I certainly do not need to connect more devices. My requirement is slightly different.

 

I am trying to set up a Two-Node Cluster using Oracle Virtual Box.

 

I need Private IP and Public IP in two different subnets and they need to be able to communicate with each other

 

Here is my setup would look like:

 

Node 1 / Server A - Public IP - 192.168.1.101  Private IP - 192.168.2.101

Node 2 / Server B - Public IP - 192.168.1.102  Private IP - 192.168.2.102

 

So I need to be able to communicate using my router any address range between 192.168.1.2 to 192.168.2.254.

 

Hope this helps.

 

I am not sure if I am breaking community guidelines but I am able to achieve DHCP from my router using another Manufacturer.

Model: R7800|Nighthawk X4S AC2600 Wifi Router
Message 5 of 8
schumaku
Guru

Re: Change DHCP Ending Address to 192.168.2.*

Leaving alone the Netgear design decision for supporting /24 IP subnets only on the consumer (and some other devices): When I see a 255.0.0.0 subnet and then ....

 


@skhaire14 wrote:

I need Private IP and Public IP in two different subnets and they need to be able to communicate with each other

 

Here is my setup would look like:

 

Node 1 / Server A - Public IP - 192.168.1.101  Private IP - 192.168.2.101

Node 2 / Server B - Public IP - 192.168.1.102  Private IP - 192.168.2.102

 

So I need to be able to communicate using my router any address range between 192.168.1.2 to 192.168.2.254.

If you want two subnets, you need either two physically independent networks, or two VLANs, or the one network you have plus a VM internal network for private VM communication purely in software on the host - ll these making up two dedicated broadcast domains. On each of these two networks, you configure an IP subnet each, say 192.168.1.0/24 and 192.168.2.0/24. On each network, you have a DHCP, as (to keep it simple) DHCP can cover only one broadcast domain, and one IPv4 subnet.

 

The communication between the two IPv4 subnets must be done on a router with two interfaces, one in the .1.0 network, one in the .2.0 network.

 

With a 255.0.0.0 subnet, all addresses from 192.0.0.0 - 192.255.255.255 are in the same subnet - and can obliviously communicate as-is - and I assume the router will allow the communication. It does just not allow issuing DHCP addresses beyond of the 192.168.1.x address range. And I don't know if these consumer routers are able to handle NAT in this huge scope.

Said that: These consumer routers only support one (assumingly small) IP subnet and broadcast domain.

Message 6 of 8
skhaire14
Aspirant

Re: Change DHCP Ending Address to 192.168.2.*

Thanks a lot schumaku.

 

1. With a 255.0.0.0 subnet, all addresses from 192.0.0.0 - 192.255.255.255 are in the same subnet - and can obliviously communicate as-is - and I assume the router will allow the communication. 

 

Yes, you are right. I just realized that router will allow communication between these IPs and I am not creating two different subnets. However, the Cluster software/VM will not check and Cluster will identify that I have 2 sets of IPs 192.168.1* and 192.168.2.*, it will think that they are in 2 different subnets and that is fine with me as this is just for my testing and not real production.

 

2 .It does just not allow issuing DHCP addresses beyond of the 192.168.1.x address range.

 

And again, I am not sure why NETGEAR does not allow DHCP beyond 192.168.1.X range as I have consumer router from different manufacturer that allows me to get DHCP address beyong 192.168.1.X.

 

However, with subnet mask of 255.255.0.0, I was able to achieve my configuration as in the VM, I have configured STATIC IPs. 

 

So here is my final configuration and that works fine.

 

Subnet MASK 255.255.0.0

DHCP Starting Address 192.168.1.2

DHCP Ending  Address 192.168.1.254

 

Virtual Machines are hosted on 2 different laptops

 

Laptop A (IP - 192.168.1.2) Node 1 / Server A - Public IP - 192.168.1.101  Private IP - 192.168.2.101

Laptop B (IP - 192.168.1.5) Node 2 / Server B - Public IP - 192.168.1.102  Private IP - 192.168.2.102

 

And this just worked fine. 

 

And thanks a lot for the help provided.

Model: R7800|Nighthawk X4S AC2600 Wifi Router
Message 7 of 8
antinode
Guru

Re: Change DHCP Ending Address to 192.168.2.*

> [...] Cluster will identify that I have 2 sets of IPs 192.168.1* and
> 192.168.2.*, it will think that they are in 2 different subnets [...]

 

   It will, _if_ the subnet masks on those interfaces are "/24".

 

> And again, I am not sure why NETGEAR does not allow DHCP beyond
> 192.168.1.X range [...]

 

> [...] I doubt that you can use anything wider than a "/24" subnet on
> these routers. [...]

 

   Still true.

 

> However, with subnet mask of 255.255.0.0, I was able to achieve my
> configuration as in the VM, I have configured STATIC IPs.

 

   "/16" is (slightly) less goofy than "/8", but why not "/24"?
Especially if the network interfaces on the computers use "/24"?  If the
".2.*" addresses are both static, then why are you trying to get the
router to deal with them?


> Virtual Machines are hosted on 2 different laptops

 

   What are the physical network interfaces?  What are the virtual
network interfaces?  How are they all configured?

 

> And this just worked fine.

 

   Perhaps for some values of "worked fine".

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