We have the problem of reading data from four PLCs with the same IP from a single PC. We want to implement 1:1 NAT, something similar to what I saw in this forum: Quick Guide: Bidirectional 1:1 NAT (SNAT, DNAT) Setup w/ working example
They used the CCR2004-16G-2S+ on that forum, but were told it was a very expensive option. I've been looking at the HEX and CRS options, but I'm not sure they all support what I need.
If anyone could help me with options, I'd appreciate it.
Well, you're well on your way, you have found the correct guide!
The (strange to me) selection of the ccr2004 was pointed out in the original thread that forms the basis to the one linked here: 1:1 NAT / DNAT configuration help - #2 by lurker888
All Mikrotik's devices that run RouterOS, which is most of them, run (almost) the same software and support the same feature set. This means that they can all fully support your use case.
There is also a sort of RouterOS "lite" - so with some limitations for very limited devices; they can be spotted as architecture: SMIPS (MIPSBE is not affected) - and also some devices (mainly CSSxxx) that can only run SwOS (or SwOS Light), these are the only ones not suitable.
Your options roughly:
The first two can be seen as "industrial" in that they are fully passive and will run well even is harsher environments. Of the CRS, some are passively, some actively cooled, but generally these are meant for desktop applications. (There are a few outdoor ones as well...)
The main difference can be seen in their performance. A good estimate for what you can expect can be obtained by looking at the Test results on the product page and look at Routing / 512 byte packets / 25 filter rules. Usually for these sorts of PLC applications all of the above listed can work fine. (The ccr2004 with 5 Gbps of forwarding performance is way overkill.)
If you're looking for a one device solution, choose one with enough ports. Even the smallest I suggest above has 5 ports, so is just enough for your (current) needs. Unless the application is fully static and set in stone it's always good practice to plan for some expansion (i.e. +1 backup PLC just being configured, etc.)
Another option is to go with a router + switch combo. The router then can be a hEX, and the switch has to be vlan-aware (managed/smart). There is no requirement for the switch to be Mikrotik brand, or Mikrotik "approved" in any way, the only requirement is that it's vlan capable.
The router+switch solution diverges a bit (not much) from the article, and that version was never written. But I'm willing to help with configuring it, if you're willing to add the solution to the article, if it turns out satisfactorily.
The router+switch solution is actually way more elegant and appropriate from a networking standpoint. The only downside is that you will have two boxes, two power supplies, etc. so it's probably not as neat or self-contained.
EDIT: If this wasn't long enough already, you may additionally wish to consider the hAP ax2 model. This has wifi, so if you would consider managing things that way easier, it's a valid choice. The wifi can be turned off fully. All other features are the same as the hEX Refresh, with roughly double the forwarding performance.
EDIT2: Clarified about SMIPS devices.
One tiny teeny correction, if I may ?
There is also a RouterOS Lite and also some devices (CSSxxx) that can only run SwOS, these are the only ones not suitable.
RouterOS Lite ? Surely you mean SWOS Lite ?
I actually meant SMIPS devices - somehow I got it stuck in my head that it had a different name (I think it should have...). Anyway, corrected.
Thanks!
Well, it probably depends from the PLC's involved, but also an old hex or even a hex lite or hap (these can be found used and even if new the hex lite costs 40 bucks and the hap 45) would most probably do.
Since it probably is "internal" only even running RouterOS 6 would do.
Just in case:
HEX Lite for routing between subnets
Port based Routing to 2 identical IP
Thank you very much for your response. I'll get a price quote for the models and purchase the one that best suits us.
In addition, I saw that a license is required to use the RouterOS software. I saw that there are levels 4, 5, and 6.
Do you know which license is best for me in this case?
License is included when you buy a device.
As @holvoetn said, licenses are included in the price. Which level is included is stated clearly on the product page for each product. The device you are likely to buy will have a L4 or L5 license. The limits are here: RouterOS license keys - RouterOS - MikroTik Documentation
Honestly, it's not even worth looking at.
None of the limits apply to your use case. Even if you develop your solution further, there's basically no way to reach the limits.
Each router specs have a license level. In general, it mainly ISP features where the level matter. For routing/NAT, it does not matter. Other than the specific features listed here: RouterOS license keys - RouterOS - MikroTik Documentation - the license does not limit anything else — now CPU/memory of hardware might, see the "Test Results" on product package for a guide on that (as noted above).
Any config should work on any router, and there is not "routeros lite" although some newer (not DNAT) features are only on ARM devices. Also, MikroTik seems to put more development/test resources on ARM platforms these days. Now some routers (CRS) do have special hardware switching features, but that wouldn't help for DNAT and doubt PLCs need much CPU. My advice if buying new I'd stick to an ARM-based model. Personally I like the RB5009 since it has good specs that might be overkill but leaves options for containers/zerotier/etc. But folks are right even an old hEX-S would likely fit the bill if DNAT for 4 PLCs is what's needed.