USW-EnterpriseXG-24 connecting in a daisy chain

[Reikalingas]

Hi,

I have 3 devices - USW-EnterpriseXG-24(XG24) and Dream Machine (DM), I thought the way it should work with the uplink ports (2x25G) on XG24 and 1 port on DM (1x10G):

I can connect DM to XG24-1 from 10G port to 25G port,

then second 25G port on XG24-1 would connect to another XG24-2 (25G port),

then on another 25G port would connect another XG24-3.(Daisy chain using 25G ports to connect multiple XG25),

but from what I tested I can only send both 25G uplink ports to the same device, am I missing something, like a setting for this or is this normal, I couldnt find anything on internet for XG24 - how to connect in a daisy chain.

Can I only connect multiple XG24 through the 10G ports?

thanks for any help

Edited May 26, 2022 by Reikalingas
adding tags

[Remarkable_Day]

Hi,

 

I believe the XG24 switches only support one autonegotiation speed across both SFP+ ports. I.e. if the DM is getting plugged into a 25G port, it will negotiate to 10G, and so will the other SFP+ port regardless of the capabilities on the other end.

 

You'd be better off connecting the DM to a copper 10G port using an RJ45 transceiver, then connecting the switches via the SFP+ if you need the full 25G link between switches.

 

This unifi forum thread details this behavior.

[Reikalingas]

8 minutes ago, Remarkable_Day said:

Hi,

 

I believe the XG24 switches only support one autonegotiation speed across both SFP+ ports. I.e. if the DM is getting plugged into a 25G port, it will negotiate to 10G, and so will the other SFP+ port regardless of the capabilities on the other end.

 

You'd be better off connecting the DM to a copper 10G port using an RJ45 transceiver, then connecting the switches via the SFP+ if you need the full 25G link between switches.

 

This unifi forum thread details this behavior.

I understand that part that 10G port connected to 25G will be still 10G, the part that I was trying to figure out, how do daisy chain three XG24 devices with 25G ports

[Remarkable_Day]

1 hour ago, Reikalingas said:

I understand that part that 10G port connected to 25G will be still 10G, the part that I was trying to figure out, how do daisy chain three XG24 devices with 25G ports

By default this should just work. 

If this isn't working, what configuration do you currently have on your switches? My points about the 10Gb was that the other switches will also only communicate at 10Gb even when using the 25G ports, because of the first negotiation link between the two SFP+ ports from the DM.

[Reikalingas]

3 hours ago, Remarkable_Day said:

By default this should just work. 

If this isn't working, what configuration do you currently have on your switches? My points about the 10Gb was that the other switches will also only communicate at 10Gb even when using the 25G ports, because of the first negotiation link between the two SFP+ ports from the DM.

no config, I just took out the box and plugged into the network, pressed adopt button and just set the names.

when i have two cables connected to the same switch, the lights are on, the second I plug 25G port into different switches the light is off (one of them off, the other one work, the first port that was plugged in that works, if you keep the second plugged and disconnect the first then the second port works) and in the settings it looks like there is nothing plugged in.

[Lurick]

Per the datasheet https://dl.ui.com/ds/USW-EnterpriseXG-24_ds

The two SFP28 ports don't support mixed speed at 25Gbps mode. Once one of the SFP28 ports is configured at 25Gbps mode the others will be limited to 25Gbps

The SFP28 ports only support mixed speed when all ports are at 1Gbps or10Gbps.

 

You cannot mix and match speeds in this case unlike in most gear. Either both SFP28 will be 25Gbps or 1/10Gbps, not a mix.

[LAwLz]

Can you please make a simple diagram of how you are plugging things in?

It is hard to understand how things are connected by how you describe things in the text.

 

3 hours ago, Reikalingas said:

when i have two cables connected to the same switch, the lights are on, the second I plug 25G port into different switches the light is off (one of them off, the other one work, the first port that was plugged in that works, if you keep the second plugged and disconnect the first then the second port works) and in the settings it looks like there is nothing plugged in.

Do you by any chance have a loop in the network? That would explain why the two interfaces won't stay on at the same time. Spanning tree will block one of the two ports.

 

Also, when you say "it looks like there is nothing plugged in", what exactly do you mean? Does the GUI report that both interfaces are down even when "the second port works" (after having unplugged the first port)?

Could it be a compatibility issue with your SFP or DAC cables?

[Reikalingas]

16 hours ago, LAwLz said:

Can you please make a simple diagram of how you are plugging things in?

It is hard to understand how things are connected by how you describe things in the text.

 

Do you by any chance have a loop in the network? That would explain why the two interfaces won't stay on at the same time. Spanning tree will block one of the two ports.

 

Also, when you say "it looks like there is nothing plugged in", what exactly do you mean? Does the GUI report that both interfaces are down even when "the second port works" (after having unplugged the first port)?

Could it be a compatibility issue with your SFP or DAC cables?

This is what I am trying to do. Basically forget Dream Machine, I jut want to connect 3 - XG24 devices with 25G port.

I dont think the cable is the issue, cos I used two cables from ubiquity and one OM4 spec cable, they all work when I plug as a single cable or two cables to the same machine.

This does NOT work (and i am trying to get this setup).

 

This works

[LAwLz]

5 hours ago, Reikalingas said:

This is what I am trying to do. Basically forget Dream Machine, I jut want to connect 3 - XG24 devices with 25G port.

I dont think the cable is the issue, cos I used two cables from ubiquity and one OM4 spec cable, they all work when I plug as a single cable or two cables to the same machine.

This does NOT work (and i am trying to get this setup).

-image-

 

This works

-image-

Thanks for the diagram.

 

Does this work?

 

 

Also, when you say it doesn't work, how exactly does it not work? Does the interface not come up at all? Or are you connecting some computers and trying to get contact between them?

[Reikalingas]

On 5/27/2022 at 4:40 PM, LAwLz said:

Thanks for the diagram.

 

Does this work?

 

 

Also, when you say it doesn't work, how exactly does it not work? Does the interface not come up at all? Or are you connecting some computers and trying to get contact between them?

yes that works (your drawing)

when I say it doesn't work (my 1st pic) it looks like - the light on the port doesn't come up, and in the controller it showing like there is nothing connected.

[LAwLz]

1 hour ago, Reikalingas said:

yes that works (your drawing)

when I say it doesn't work (my 1st pic) it looks like - the light on the port doesn't come up, and in the controller it showing like there is nothing connected.

That is very strange.

And you are sure that all connections are 25Gbps? It's not one cable that is damaged and thus negotiates down to 10Gbps?

 

Does the switches have any logs that you can look for errors in?

[Reikalingas]

17 hours ago, LAwLz said:

That is very strange.

And you are sure that all connections are 25Gbps? It's not one cable that is damaged and thus negotiates down to 10Gbps?

 

Does the switches have any logs that you can look for errors in?

there is no errors its not displaying anything.

 

connections on the software end are set to 25G speeds, cables are all good, because when I plug one of them its working (or two cable but only to the same machine, not different machines), tested on 2 different types and 2 cables each type, and tested both ports separately on all tree machines, the only combo is not working is the only one I need to work. (pic of the one its not working)

 

[LAwLz]

1 hour ago, Reikalingas said:

there is no errors its not displaying anything.

 

connections on the software end are set to 25G speeds, cables are all good, because when I plug one of them its working (or two cable but only to the same machine, not different machines), tested on 2 different types and 2 cables each type, and tested both ports separately on all tree machines, the only combo is not working is the only one I need to work. (pic of the one its not working)

 

Is there anything else connected to the switches?

Are you sure there is nothing configured on the switches? That they are factory reset?

 

I am not that familiar with Ubiquiti, but the fact that you can connect two switches together using two cables according to this diagram:

On 5/27/2022 at 11:43 AM, Reikalingas said:

This works

sends some pretty big alarm bells in my mind. One port should become disabled if you connect them like that in order to prevent loops.

 

Could it be that the ports on one switch are configured as a port-channel? That would explain why it behaves in this way. 

 

 

What happens if you connect all three switches with RJ45 cables? So instead of using the 25Gbps ports, you use the 1Gbps ports. Just as a test.