Networking Problem: Mixed DHCP servers for Ethernet and Wifi

[ksnax]

I will preface this by saying that I can accept if I just need to find a better way to set things up, but I am not having any success getting my wifi cameras to feed into BI from a physical subnet.

I have my primary ISP provided gateway setup with DHCP for everything wired directly to it with the wifi disabled. It is horribly unreliable with DHCP when a lot of devices are connected - even forgetting reserved IPs, so I installed the secondary wifi router in another location to mitigate that issue. I am able to connect to and view the cams from the wifi side of the LAN, but BI is unable to reach them on that network.

Am I just making problems for myself by running two DHCP servers here, or is there an easy way get it all talking? Maybe I just need to learn up more on port forwarding?

I have another router I could throw in between my entire LAN and the internet gateway to make that a lone DHCP server. I don't need the extra IP addressing of the subnet. Maybe that makes more sense to do.

 

[lcam]

I will preface this by saying that I can accept if I just need to find a better way to set things up, but I am not having any success getting my wifi cameras to feed into BI from a physical subnet.

I have my primary ISP provided gateway setup with DHCP for everything wired directly to it with the wifi disabled. It is horribly unreliable with DHCP when a lot of devices are connected - even forgetting reserved IPs, so I installed the secondary wifi router in another location to mitigate that issue. I am able to connect to and view the cams from the wifi side of the LAN, but BI is unable to reach them on that network.

Am I just making problems for myself by running two DHCP servers here, or is there an easy way get it all talking? Maybe I just need to learn up more on port forwarding?

I have another router I could throw in between my entire LAN and the internet gateway to make that a lone DHCP server. I don't need the extra IP addressing of the subnet. Maybe that makes more sense to do.

I think you are causing yourself more pain by adding routers. I would contact the ISP regarding the reserved IPs not sticking.

 

[mikeynags]

Dump the ISP DHCP and do roll your own through your own router. Have your modem directly connected to your own separate router and manage it from their. With that, if you decide to change ISPs, your local network and its IP scheme will still be all set.


Sent from my iPhone using Tapatalk

 

[SouthernYankee]

What is your overall objective in creating this network topology ?

1) What is the ip address on the cameras in the blob ?
2) Does the BI computer have two NICS ?
3) Are you trying to set up a VLAN for the cameras ?
4) What is the physical distance between the first and second router ?
5) What is the distance from the BI computer to the wifi camera ?

 

[ksnax]

Like Mikeynags said, I think I am just going to throw a real router in between my wifi router and the gateway, making it the soul DHCP server for both segments of the network. It is just going to be a pain in the ass otherwise. No hassles either if my gateway or ISP change after that.

 

[SouthernYankee]

You can set up a network without DHCP. My camera network, a separate network does not have a router all IP address are static.

 

[HackitZ]

I live in Canada and use Cogeco.
I have to use there modem/wifi router.

What I did was put the Cogeco router in beige mode. This only sends my router the ip.

I then was able to use my own routers as usual.

Sent from my Pixel 4 XL using Tapatalk

 

[jmhmcse]

As you can tell, there are multiple solutions for you to consider.

Most typical method, IMO, is to use the ISP's device only as the gateway connection to the WWW. All other duties, firewall, dhcp, etc, are provided by your router.

A little work now, but in the long run you'll have a network that will be consistent and independent regardless of who you current/future ISP provider is/will be.

Milestones to accomplish this would be

1. return all devices to DHCP, without reservations
2. turn off DHCP from the ISP's gateway
3. be sure the WAN port of your router is connected to the ISP gateway
4. configure router's DHCP range; e.g. 10-254 and DNS servers e.g. 1.1.1.1, 1.0.0.1
5. connect switch to your router
6. connect all other network devices to your switch
7. if needed, restart all devices so they all are on the same network address; 192.168.1.#; default gateway is YOUR router, DNS is what you configured in your router
8. configure your DHCP with MAC to IP reservations

You should now have all you devices in one network subnet which will operate (locally/internally) even if the ISP gateway is turned off. No special routing required, no additional routers required.

Obviously I've made some presumptions that devices are close enough to one another to re-cable as described and that the end-goal is to have a simple and reliable network.

 

[eeeeesh]

Am I just making problems for myself by running two DHCP servers here, or is there an easy way get it all talking? Maybe I just need to learn up more on port forwarding?

I always thought when you have two DHCP servers you get into a 'double NAT' situation

"Double NAT is when you connect your router behind another router creating two different private networks. For example, connecting your NETGEAR router behind a modem/router provided by your ISP. Double NAT does not prevent your devices access to the internet but may cause problems with playing online games, opening a specific service port, connecting to a VPN tunnel, or visiting secure sites with SSL. Also, the devices connected to the first private network may not be able to communicate to the devices connected to the other private network. "

What is Double NAT? | Answer | NETGEAR Support

What is Double NAT?

kb.netgear.com

 

[jmhmcse]

POSTING MUST REMOVE SPACES, HAD TO RE-EDIT TO KEEP FORMATTING AS DESIRED

If you have a DHCP enabled device behind another DHCP device you have a double nat (actually for residential modems PAT not NAT); e.g.


--------------------------------------------------DHCP 192.168.100.#---------------DHCP 192.168.1.#
=======ISP MDM RTR===========Home RTR1=================Home RTR2===========> clients
public IP----24.#.#.#-----------------24.#.#.#----192.168.100.1---------- 192.168.100.2----192.168.2.1-------192.168.2.#
----------------wan-----------------------wan-----------lan--------------------------wan------------------lan

OR

-----------------DHCP 192.168.100.#------------------------------DHCP 192.168.2.#
==========ISP MDM RTR Gateway================Home RTR==========> clients
public IP------24.#.#.#---192.168.1---------------192.168.100.2----192.168.2.1----------192.168.2.#
------------------wan----------lan-------------------------wan------------------lan

Devices with 192.168.2.# addresses would be double-Pat'ted

======================================
======================================

You should have only one DHCP server enabled, be it in the ISP's device or your own. If you have your own router, then placing this function within your own device is common practice. Having two network address ranges handed out by two DHCP servers will cause multiple headaches regarding connectivity between all the home devices. (there would be times when multiple network addresses and DHCP servers might exist in home networks, but that's not the norm)


What I recommended has only one DHCP server ...

-----------(Gateway/NO DHCP)---------DHCP 192.168.1.#
=======ISP MDM RTR===========Home RTR1===============> clients
public IP----24.#.#.#------------------24.#.#.#----192.168.1.1----------------192.168.1.#
------------------wan----------------------wan-----------lan

Turning off the DHCP server on the ISP's router would normally revert the device into a GATEWAY. The Public IP of the GATEWAY (lan port) becomes the WAN address (wan port) of the router connected to it. If not automatic, then it would need to be configured manually.

 

[ksnax]

As you can tell, there are multiple solutions for you to consider.

Most typical method, IMO, is to use the ISP's device only as the gateway connection to the WWW. All other duties, firewall, dhcp, etc, are provided by your router.

A little work now, but in the long run you'll have a network that will be consistent and independent regardless of who you current/future ISP provider is/will be.

Milestones to accomplish this would be

1. return all devices to DHCP, without reservations
2. turn off DHCP from the ISP's gateway
3. be sure the WAN port of your router is connected to the ISP gateway
4. configure router's DHCP range; e.g. 10-254 and DNS servers e.g. 1.1.1.1, 1.0.0.1
5. connect switch to your router
6. connect all other network devices to your switch
7. if needed, restart all devices so they all are on the same network address; 192.168.1.#; default gateway is YOUR router, DNS is what you configured in your router
8. configure your DHCP with MAC to IP reservations

You should now have all you devices in one network subnet which will operate (locally/internally) even if the ISP gateway is turned off. No special routing required, no additional routers required.

Obviously I've made some presumptions that devices are close enough to one another to re-cable as described and that the end-goal is to have a simple and reliable network.

View attachment 53958

Yep, this is ultimately what I will end up with. Thanks for the rundown.

I actually tried to do this today until I screwed something up and had to reset the ISP modem. I did not realize it until today, but it has been over 2 years since I last set it up, and going back to factory defaults seems to have cleared up the issues I was having with it. (Previously, I had actually completely rebuilt the routing of my network remotely from 2200 miles away after making a careless error that only left me with my home PC on the same LAN accessible.) Might just leave well enough alone for now, but this is the backup plan.

I was aware that nested DHCP could be a problem. No issues for internet access, but the ISP gateway simply did not want to see the secondary router beyond it's assigned IP address.

 

[Edcfish]

The only thing I would do different that what jmhmcse has suggested is: set the DHCP IP address range to xxx.xxx.xxx.100-xxx.xxx.xxx.254 and then use the sub-100 IP addresses for cameras (and other devices where you want a static IP) and then assign the IP in the camera software instead of (or, i suppose, in addition to) configuring DHCP with addresses based on the devices' (cameras') MAC addresses. In my experience it is just a little bit more reliable, and if the router ever goes down and needs replaced, a little less to do in the re-set-up.

 

[mikeynags]

I do exactly the same with specified DHCP ranges. I have a range for everything that uses a DHCP reservation, a range for my VPN and everything else including cameras, networking gear etc. is statically configured.


Sent from my iPhone using Tapatalk

 

[IAmATeaf]

The basics of the problem here is that you have 2 sub networks, 192.168.0.x and 192.168.1.x and without something to route between these 2 networks devices on one won’t be able to talk to devices on the other.

So either set all your devices to be on the same network, or configure a device to perform the routing function or maybe get another network card for the BI box and configure that network card to be on the 192.168.1.x network. The BI box would then be the box you’d access in order to directly access the cams.