Managed Switches "Out of the box".

[Tharon]

We had recently started using Ethernet networks on some smaller machines. Mostly just a PLC, HMI, Laptop Port.

As we had begun moving to small CIP networks, a PLC, two drives, and an HMI (isolated network), it was suggested that we move to Managed Switches. And a few people had purchased some Managed Switches and installed them (Just plugged them in and left them at that).

But my concern is, does a Managed Switch do anything differently "out of the box"? Or does it need to be configured to provide any benefit to a network? There's a lot of stuff on these forums about Managed Switches but I couldn't find anything about what they did by Default.

 

[JesperMP]

You mentioned CIP, so I am guessing you have an Ethernet/IP network.
At least a managed switch with IGMP snooping has this feature on by default.
And most managed switches have diagnostics features that may be useful, even if you just use them with default settings.
I do not know so much about Ethernet/IP, but for Profinet if you have included the switch in the topology, and have given it a device name, then that will give you pretty decent diagnostics. I suspect it to be the same with Ethernet/IP.

 

[Tharon]

Yes, they would be on an Ethernet/IP network with CompactLogix PLCs and some AB Drives, mostly. Sometimes Point/IO Remote IO units or Robot controllers, HMIs, etc.

These few that have been changed have been nothing more than taking an existing, running, machine with an unmanaged switch, and powering it down, removing the unmanaaged switch, physically installing the managed switch, and powering it back up. Nothing changed program-wise. They did so with the belief that the managed switch would make the network "stronger" (less likely to have communication issues). I did not think that out of the box it would do anything differently like that. And I don't think they are using it in any way to go and look at a diagnostics during or after the faults that happen.

 

[JesperMP]

IGMP snooping will make the network "stronger", by filtering traffic so it does not burden unrelated network nodes.

 

[Tharon]

Ok. So there would be some out of the box benefit. Related to the size of the network and whether or not it's connected to anything external to itself. Thanks.

 

[JohnCalderwood]

you could do some simple configs, to set up Automatic Device Replacement, so your techs could replace a drive or an I/O adapter, and the replacement device would be given the correct IP address...

 

[LoganB]

As far as I know (my sister is a networks security guru for a Rockwell Distributor) managed switches out of the box are unmanaged switches. They need to be configured to enable things like IGMP snooping.

 

[Tom Jenkins]

Phoenix Digital has some innovative products and great tech support: http://www.phoenixdigitalcorp.com/products.html

 

[Phil Buchanan]

As with most things in life it depends. It depends on the switch make and model.

Most of the time out of the box all managed features are disabled until you set them up but sometimes on some switches some things are enabled and will cause problems if not configured.

General rule is don't buy managed unless you plan to configure them and use them.

Also without going into a deep dive here putting a managed switch in and not configuring it is worse than having an un-managed switch because you can have problems with it that you would not have with the un-managed switch.

 

[Toine]

Most managed switches are managed through a web interface and just about all of them have an IP address of their own, for management purposes. They often come with a preset fixed IP. Chances are you may install two or more in the same network. Two or more devices on one network with the same IP address is trouble (search duplicate IP if this is new for you, you are curious and want to know - yes you should want to know these things).

Apart from that, the preset IP address of your switch may actually be part of a DHCP range on your network and thus be leased to another device on the network. Yet another way to run into duplicate IP's. This latter case of duplicate IP's may rear its' ugly head long after installing the switch, so nobody would realize it has anything to do with the switch.

Therefore, at the very least check and if necessary change the default IP address to something outside of any DHCP range and not colliding with any other fixed IP device in order to avoid duplicate IP's. Document the address, even if you don't change it. Mark the IP address on the device itself. Share with IT if they have anything to say on the network and IP addressing.

 

[rdrast]

Depending on your network, 99.9% of the switches just 'Out of the box' will shut down upstream communications. I have no idea why everyone seems to think it a great idea to enable spanning tree by default, but it is a serious problem in some networks if it is enabled on end-point switches.

 

[mk42]

As with most things in life it depends. It depends on the switch make and model.

Most of the time out of the box all managed features are disabled until you set them up but sometimes on some switches some things are enabled and will cause problems if not configured.

General rule is don't buy managed unless you plan to configure them and use them.

Also without going into a deep dive here putting a managed switch in and not configuring it is worse than having an un-managed switch because you can have problems with it that you would not have with the un-managed switch.

Agree 100% on this. If the switch is called "managed", don't be surprised that you need to manage it. By the same token, don't be surprised when you buy a PLC, and your Programmable Logic Controller doesn't actually do anything out of the box until you program it.

That said, I have used some managed switches that were designed with the assumption that they would be powered on and then left unmanaged. Each switch had 2 part numbers, depending on whether you wanted it pre-configured for Profinet or EIP, and the settings were chosen to be the most likely useful (or least damaging) in each situation.

 

[ndzied1]

Phoenix Contact has some managed switches (they actually call them Lean Managed Switches) that are pre-configured to be used in Ethernet/IP networks.

Here is an example of an 8 port switch:
https://www.phoenixcontact.com/onli...pcck=P-08-10-09-10&tab=1&selectedCategory=ALL

<disclaimer - I work for a company that distributes Phoenix Contact products>