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Why Producers duplicate IPv4 addresses and the way IE switches assist clear up the problems

If this matter piqued your curiosity, you’re in all probability impacted by or at the very least interested by duplicate IP Addresses in your industrial community. You aren’t alone. It may be a bit of bewildering. There doesn’t appear to be any cause these days to have duplicate IP Addresses, not to mention do it on goal. Let’s unravel the thriller.

Firms that construct subtle machines have made the transition to Web Protocol because the communication protocol inside their machines. IPv4 is the best protocol to make use of. There are many software program libraries within the ether primarily based on IPv4. These firms’ core competency is {the electrical} and mechanical facet of their machines, not the software program that runs the machine and due to this fact they don’t have subtle software program groups. Once you’re writing communication software program and software program will not be your core competency, what’s the best and least problematic strategy to determine the parts inside your machine? Reply: Static IP Addresses. The choice to static IP Addresses is a extra sophisticated course of involving dynamic IP Tackle task, together with a fancy activity of figuring out which IP Tackle the person parts obtained.

The IP Addresses have been duplicated on goal. The software program within the machine makes use of static IP Addresses to determine particular person machine parts as a result of it’s simpler for the machine builders. Every machine they construct has the identical software program (SW). Subsequently, they use the identical static IP Addresses. When you’ve got bought two or extra of their machines, then you could have duplicate IP Addresses. To be truthful, it might be a lot more durable and price prohibitive to provide every part of every machine a novel IP Tackle.

Determine 1: Robots symbolize a number of machines with equivalent parts and software program

The robots within the image above are an instance of a classy machine. Every robotic has the identical parts and the identical software program. Every part has its personal statically assigned IP Tackle. This observe will not be restricted to robots. Bottling machines and diaper making machines are manufactured in the identical manner.

Why is that this an issue?

So long as you possibly can include the broadcasts of IPv4 Addresses of the parts to remain inside the machine, you have to be OK. There’s at all times one publicly distinctive IPv4 tackle on the machine which represents your entire machine to the surface world. Once more, so long as you solely use this one IPv4 tackle to speak with the machine, it shouldn’t current any issues. More often than not that is the way it’s performed and everyone seems to be joyful.

Alongside comes the necessity to improve productiveness. To extend productiveness, you want extra knowledge. And the place is that this knowledge? One place is contained in the machine. Now you could talk with the parts contained in the machine. After getting a couple of machine, how must you talk with the inner parts which have the identical IPv4 tackle? That is the issue.


Earlier than describing options, I’d prefer to uplevel the dialogue to speak about Community Tackle Translation (NAT) on the whole.

All people ought to find out about NAT. We use NAT day by day whether or not we all know it or not. The IPv4 router in our properties makes use of NAT. The IP Tackle assigned to your own home gadgets (together with your laptop computer and smartphone) is a non-public IP Tackle. This non-public IP Tackle will not be routable on the Web. Our neighbors all have in residence gadgets with the identical IPv4 addresses. It’s not an issue as a result of our residence routers use Community Tackle Translation (NAT) to transform non-public IP Addresses to a publicly routable IP Tackle so we are able to talk with gadgets on the Web. The Web service suppliers use non-public IP Addresses for in residence use as a result of it’s simpler for them. There usually are not sufficient IPv4 addresses on the earth for each IP succesful machine to have a novel IPv4 tackle. And let’s face it, we now have not transformed to IPv6.

Your own home will not be the one place NAT is used. Industrial networks additionally want to make use of NAT as a result of subtle machines have the identical IPv4 addresses.

There are actually solely two methods to resolve duplicate addressing issues for industrial networks. The obvious manner is to insert a further Layer 3 machine resembling a firewall or router between the machine and the remainder of the community—simply to translate Personal IP Addresses. That is just like what you could have at residence. This resolution requires a particular community machine for the aim to transform non-public IPv4 addresses to publicly distinctive IPv4 addresses. The downside is, that it’s a further machine to buy and handle and, configuration and administration of this Layer 3 community machine might be complicated, requiring somebody with IT abilities to setup and preserve them.

The much less apparent manner is to make use of a Cisco Industrial Ethernet (IE) change to do the IPv4 translation. When the IE change solves the duplicate IP addressing downside, it’s utilizing Layer 2 NAT. Plus, in my biased opinion, configuring Layer 2 NAT on a Cisco IE change is less complicated than configuring NAT on router or firewall. There’s in all probability an Industrial Ethernet change in your community already connecting all of the machines collectively. Why introduce a further community machine? Maintain the identical easy community structure you could have with a Cisco IE change and clear up your duplicate IPv4 addressing points, too.

Determine 2: IE-4010 connecting a number of complicated machines

In determine 2 above, every robotic has the identical IP Addresses for its inner parts. The Cisco IE change will translate the duplicated non-public IP addresses of the parts of every robotic (ie: complicated machine) into publicly distinctive IP Addresses because it receives the Ethernet frames from the robots.

Pattern IOS CLI configuration for the Cisco Industrial Ethernet

That is how you’ll configure a Cisco Industrial Ethernet change to supply L2NAT for the primary two robots on the left in Determine 2. The remaining three robots could be similar to the primary two.

You begin by defining which IPv4 Addresses to translate. The Cisco IE doesn’t know which publicly or non-public IP addresses you need to use. You must inform it. You outline the whole translation.

Outline a translation occasion for every robotic. The ‘leftmost’ robotic would have this translation occasion for 3 of its inner parts. The ‘nextleftmost’ robotic would have the identical non-public IP Addresses however distinctive public IP addresses.

Word: The IP Addresses for the within hosts are the identical in every of the 2 translation cases, and the translated public IP Addresses are distinctive. They must be distinctive if they’re for use within the upstream community to uniquely determine the robotic parts.

The subsequent step within the configuration course of is to use the interpretation cases to the proper interface. The ‘leftmost’ robotic is related to port Gi1/2, and the robotic subsequent to it’s related to Gi1/4.

Disclaimer: This configuration, whereas legitimate, is simply an instance.

Relating to configuring something within the IOS CLI, the instance above exhibits how easy it may be. For these of you who don’t like utilizing the IOS CLI, the identical configuration might be performed utilizing the IE’sweb primarily based GUI.


For these of you searching for an answer to the duplicate IP Addressing downside, utilizing the IE change you have already got in place simply is smart. For these you with out an IE Swap, now you could have an excuse to deploy one within the entry layer. Particularly in case you have unmanaged switches within the entry layer as we speak. Utilizing an IE change is a one field resolution. The IE switches do the IPv4 tackle translation at line charge. In addition they translate the IPv4 addresses within the payload for ICMP and ARP.

L2 NAT is simply one of many many options on Cisco’s IE switching options that clear up buyer points with high quality and reliability.

Get extra info on Layer 2 NAT

Be taught extra about IE Switching

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