NEMS With Multiple NICS

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SilentWoof
Junior Member
Posts: 3
Joined: Sat Nov 14, 2020 8:54 am

NEMS With Multiple NICS

Post by SilentWoof »

Platform: RPi 4 (4Gb RAM)
NEMS Linux version: 1.5.2
NEMS Build: Sorry, I don't know where to find this...

Hello Community and Robbie,

I am looking for some help to configure (if it's even possible) the NEMS server to connect via eth0 for monitoring and via wlan0 for (most) human interaction and internet connection.

I know that this is probably a strange configuration, but here is the reason why...

At work, I need to monitor devices on an air-gaped network. The NEMS server is being deployed in a broadcast environment where we may use a a network for all camera control that is physically isolated from the internet and general use.
On this network there are no network services running such as DHCP and every device is configured manually.
The reason for this is there is a complicated set up where a control connection is made between any one of the 130+ cameras on the network and one of the 7 control surfaces via one of two bespoke camera servers.

The fundamental concept is that the active server listens to a protocol issued by our video router (again on a different physically isolated network) until it receives information about a video source being routed to a video destination ( a cross point). When the server receives information about a cross point that it knows about, it makes a data connection between the IP address of the camera to the IP address of the controller so that control of the relevant camera can be established. I should say that the camera servers are connected to the camera network and the routing network on two separate NICs.

As you can imagine, if DHCP is running on the camera network, and lease times are exceeded when cameras are temporarily repurposed then very quickly chaos can ensue.

Ideally, I need eth0 on the camera network to monitor the status of the cameras, controllers and servers, and wlan0 connected to the general wi-fi network for human interaction of the NEMS Server.

I have managed to get hosts monitored on the camera network and that all seems ok, and I can gain access to the UI on both the eth0 and wlan0 but NEMS is not showing a connection to the internet, and showing a warning on the home page about no internet connection.

I have tried a ping to 8.8.8.8 from the terminal and again, no joy.

I though this could be something to do with network priority and I have manged to set the eth0 priority to 50 and the wlan0 priority to 100 but still no luck.

I followed the directions on the link below to set the network priorities for the associated connections.
http://bss.technology/tutorials/red-hat ... -in-linux/

I have googled around, but cant find any information about multiple NIC setup for NEMS Linux but I could't find anything.

Sorry for the long post, and if any additional information or configs would be useful, then I'll happily post them.

Thank in advance for any help that is offered.

Best,

SW
SilentWoof
Junior Member
Posts: 3
Joined: Sat Nov 14, 2020 8:54 am

Re: NEMS With Multiple NICS

Post by SilentWoof »

UPDATE

I tried:

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ping -I wlan0 8.8.8.8
and I can confirm that I get an response.
SilentWoof
Junior Member
Posts: 3
Joined: Sat Nov 14, 2020 8:54 am

Re: NEMS With Multiple NICS

Post by SilentWoof »

UPDATE:

So I think I have made it work, but being a novice, I may have made a change that breaks other things :D

I did a:

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netstat -rn
and got the result:

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Kernel IP routing table
Destination	Gateway         	Genmask         	Flags   	MSS Window  	irtt 	Iface
0.0.0.0		10.10.20.254    	0.0.0.0         	UG        	0 0          		0 	eth0
0.0.0.0         	192.168.110.1   0.0.0.0         	UG        	0 0          		0 	wlan0
10.10.20.0      	0.0.0.0         	255.255.255.0   U         	0 0          		0 	eth0
192.168.110.0  	0.0.0.0         	255.255.254.0   U         	0 0          		0 	wlan0
I then did:

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sudo route del default
netstat -rn
and then got this result:

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Kernel IP routing table
Destination     	Gateway         	Genmask         	Flags   	MSS Window  	irtt 	Iface
0.0.0.0         	192.168.110.1   0.0.0.0         	UG        	0 0          		0 	wlan0
10.10.20.0      	0.0.0.0         	255.255.255.0   U         	0 0          		0 	eth0
192.168.110.0  	0.0.0.0         	255.255.254.0   U         	0 0          		0 	wlan0
After this trying a

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ping 8.8.8.8
gets a response. Also I am able to update using

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sudo nems-update
.

One more thing to note is that the default webpage for NEMS now does not have the red warning banner about not being able to connect to the internet.

I'm not sure if I fave achieved my goal correctly or not, but everything seems to be working correctly now.

I would be very grateful if someone much smarted then I were able to tell me if I have inadvertently broken things, or weather I have been able to achieve my goals.

Thanks
SW
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