Showing results for 
Search instead for 
Did you mean: 

Cisco 3850 does not support REP (Resilient Ethernet Protocol), alternative??



In our plant, we have a Ring of Industrial Switches that run the Cisco REP (Resilient Ethernet Protocol) for fast convergence.


In our server room, we planned to place a Cisco 3750X because that switch is stackable (redundancy),  supports this protocol and is ideal for our server connections. Also, this switch 3750X is adviced as explained in this document released by Rockwell/Cisco:


But now comes the issue: when navigating to the Cisco 3750X page, it says: "please consider buying the better next generation Cisco 3850". This means our boss/end customer does not want the 3750X anylonger because he fears it will be investing money in old technology. But when looking for "Resilient Ethernet Protocol 3850" we find out it is not supported.


The only switch that we can find that has the "REP" support and that is "Orderable / New" is the Catalyst 4500E-R (modular switch) with SUP6LE controller. If we want this redundant and put dual controllers and dual 10/100/1000 cards in it, pricing expands x6 from dual 3750X 6,000 usd to 4500E-R 30,000 usd. Of course, the end customer finds this also not acceptable and wants an explanation for this. We know that a REP ring can support 1-not REP compatible device, so the 3850 or even the 2960X will work, but customer prefers the 'ideal' solution with full REP.


Is there any solution for this? Can we expect REP to be supported on future 3850 releases? Is there any other switch we can use that is

- redundant / stackable / dual power

- has full gigabit connectivity + sfp fiber possibility

- is "orderable" and is not in the process of being succeeded by another switch

- REP + mst support


Also, what are the expectations of the End Of Life for the 3750X? If we could have any written confirmation that it will not be EoL soon, we can try and use that to still order the 3750X.


Best Regards,





Accepted Solutions
Cisco Employee

Is there any solution for this? Can we expect REP to be supported on future 3850 releases? Is there any other switch we can use that is


Answer:- Currently there is no plan to have the REP on the 3850. I dont have the timeframe when that will/can be implemented.



 End Of Life for the 3750X :- I dont see this going EOS as of now who told you that?





*********Please do not forget to rate if this info is helpfull******



OK so a few months after your response, EOL was annouced.

Is there still no plan to have REP on the successor, the 3850? What are 3750X users that use REP are supposed to replace their switches with in the future then?


Hi Joris,

I recently learned that 3850 is going to support REP in release 16.2.1 It will be available in the coming months. We are also waiting on it...

An alternative that you could consider  today is 2960XR. I believe it also has all the features you need.

best regards,

Wim Van Liedekerke


It seems that the guide was put out prematurely.

REP will be supported in 16.2.2 – July 2016 (on the 3850).


O common... 16.2.2 is still not released, your response was from 8 months ago. We still have no REP on the 3850X ??? It is unclear if the 16.3 firmware supports REP, I can't find this. The 16.2.2 document mentions REP but is a delayed release (not downloadeble), the 16.3 release notes do not mention REP.

EDITI found a manual that mentions REP config on 16.3 but a manual is not a 100% go for purchase for me.


The Cisco Feature Navigator does not list it as being a supported feature on the 3850 in any of those releases yet either ...


Cisco "TAC" has officially replied us it is supported from version 16.2.2 onwards on IP Base and IP Services image.

Support for Resilient Ethernet Protocol (REP):

3850 LAN Base - not supported

3850 IP Base and IP Services - yes, version 16.2.2 onwards


Actually I see 16.2.2 was released - under deferred releases.  So that means it has a critical bug and should not be used.


This is interesting.  In the release notes for 16.3.2 it mentions lots of fixed bugs for REP.  This implies it has REP support.


Cat3850: REP LSL PDU counter up on shut down interface


REP Multicast Traffic does not resume after neighbor switch reloaded


REP Multicast packet loss for 10+seconds during re-convergence


SVI Ping fails after HA-SSO during REP Topology change


REP packet drop after 3rd SSO on one of the nodes


Cat3850: REP LSL PDU counter incrementing when link is in down state (remote end)

The release notes mention this unresolved bug.


During REP ring failure, duplicate packets may be seen for a short time


Yes it is all very weird because it is not in the feature navigator but it is mentioned on some other locations. We called a Cisco sales person and he would call us back in 10 minutes but 2 hours have past and no response. I guess Cisco doesn't know for sure themselves. Hopefully get an answer very fast.

Few years ago we bought a 2960X because the feature navigator said it supported REP. Turned out it didn't support REP and after we mentioned that they just made the change in the feature navigator. So this REP support uncertainty has been a real pain for several years.


I have confirmed that the REP feature is supported on the 3850 in the latest code release.


Take a look at the Industrial Ethernet 5000 Series switches. These are intended to serve as an Industrial Ethernet aggregation switch with 10G SFP+ ports and up to 24 10/100/1000 RJ45 ports. The IE5K supports all your feature requirements with the exception of stacking. However, in an industrial environment stacking can introduce some challenges. Remember, that stack failover is not very fast. So building dual-ring topologies on pairs of standalone switches might be more suitable.Especially when running REP where link failure detection and convergence is about as fast as it gets with Cisco switches. If you haven't already read Cisco's Converged Plantwide Ethernet Design and Implementation Guide you may want to. This is a large DIG but your scenario is directly addressed by CPwE.

Cisco CPwE



I read the complete CPwE guide about 3 years ago and we have built plants upon this guide. We use the 3750X as mentioned in the CPwE guide. In fact, almost that complete guide is based on ring structures with the Stacked 3750X as the central routing point linking all rings together. Just browse through it and all you see is this architecture (f.e. page 3-20).

So please don't say that the 3750X stacking is not ideal and that I should read CPwE?!

Now, these plants can start questioning that we used obsolete technology while Cisco/Rockwell are still mentioning this architecture in CPwE!

Content for Community-Ad