CCTV Articles

The Advantages of an NVR with Dual NICs

Here at we have had a few calls lately concerning our NVRs that have dual NICs. If you don’t understand “dual NIC”, what I mean is that it has 2 Ethernet ports. Customers are wondering what is the need for two NIC cards in the back of the unit. To answer the question, “What is the reasoning behind the two Ethernet ports (NIC) on my NVR?”, there are three advantages to having these dual NICs. Based on the network you have, or want to have, you may not be interested in any of these advantages. Let me be clear when I say just because your NVR has them you do not need to occupy both NICs. However, if you are going to use only one Ethernet cable make sure it is plugged into port# 1. That being said, the general advantages for Dual NICs are Multi-Address, Fault Tolerance, and Load Balance. If you do not know what these mean don’t feel bad, you will have a better understanding once you finish this article.

First of all, allow me to explain what Multi-Address means/does. Multi-Address is a tool to have two different IP schemes connected to your NVR, obviously your main network will be for the NVR and will plug into port# 1, then the reasoning for port# 2 will be for a switch, whether it be PoE or not so your cameras and NVR will not be on the same network. The advantage to this is the NVR will be on your every day network, and the cameras will be on a separate network. So if you have a 32 channel system and don’t want 32 IP cameras bogging down your main network you can have them separate from the NVR on the main network but still be able to add them with no problems. The three pictures below are very important to pay attention too. First of all, look at the bottom picture, this just shows you that the NIC on the left is port#2, and the NIC on the right is port#1. So in my demo, the white cable will be my main network going to the NVR, and the yellow cable will be my secondary network that plugs into the POE switch for my cameras. The other two pictures are showing you the configurations you will need to make in the network tab. The top picture being the main network in “Ethernet1” configured as “Multi-address”, with a gateway of and an IP of The middle picture is showing you the secondary network for the cameras in “Ethernet2” configured as “Multiaddress”, with a gateway of and an IP of It is crucial that the two networks be configured with different gateways and IP’s, otherwise you will cause a conflict and this will not work.

Dual Nic Art.

Dual Nic Art2


Another thing you will need to know is when you go into “Remote Device” and try to add the cameras while they are on the secondary network, keep in mind the “IP Search” WILL NOT find them. You will need to do a “Manual Add” and when you do so the gateway will be and the IP address will be 192.168.2.? whatever you configure. As long as you follow those simple steps you will be good to go.

Now, the second advantage to the dual NICs is something called Fault Tolerance. In simple terms, you can have your NVR wired to two different switches on your network. The benefit to this is if one switch goes down, the NVR will swap over to your secondary switch, letting your NVR remain operational. So say you have switch “A” wired to the first Ethernet port of the NVR and switch “B” wired to the second Ethernet port. Switch “A” is going to be your primary switch, where your NVR will pull its connection from all the time. Switch “B” is going to be your secondary port, where your NVR will pull its connection from if switch “A” was to go out. The way you configure this is extremely easy. In the network tab you will need to change the “Network Mode” to Fault Tolerance. Once you do so you will see that “Default Card” changes to “Primary Port” and that is where you will configure switch “A” to be your primary switch and switch “B” to be the secondary switch. After you make those few simple changes you are all set. If for some reason switch “A” goes down, switch “B” will kick in automatically, allowing your system to remain operational. The picture below shows the jump from switch “A” to switch “B” happening, how quick it works, and you do not have to do anything. Look at where the ping is going steady, then I disconnect the power from switch “A”, you see it timed out once, and immediately switch “B” kicked in and the ping remained steady. This just goes to show you how quick the NVR does this by itself, no command necessary from you.

Dual NIC ping

The third advantage to having dual NICs is a little something called Load Balance. This means exactly what it sounds like, it is balancing the load on your network. This configuration will require a piece of equipment that we do not offer, something called a managed switch. The managed switch manages the load on your network and keeps the balance nice and steady. So, if your network is being bogged down, the manage switch will take things from your main network and switch it to the secondary network, so your connection never loses its strength. Now, the configuration starts the same way above. Change “network Mode” to Load Balance and set port#1 to be main and port#2 will be secondary. Also, say you do not want to buy a managed switch and so you think load balance is useless to you. You are wrong, there is a way you can still use the configuration. Each NIC is 1Gig of throughput data, if you set network mode to Load Balance that combines the NIC’s and now you have 2 Gigs of throughput data. There are a few things that make that worth your while. You can increase the resolution of your IP cameras and you can increase the bandwidth of the cameras. I’m sure there are quite a few more, but I will keep it as simple as possible. Those are all the things that are beneficial to you with the NVR’s with dual NIC’s. Hope this was helpful, if you have any configuration questions you can call our free tech support line at 866.573.8878.

Leave a Reply