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Senior Member
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Link aggregation between switches blocking ports?

[ Edited ]

My network setup is as follows:

 

1 US 48 POE switch in the attic. Attached to it are the Cloudkey, a USG and two UAP-AC-Pro's.
There are also three Synology NAS devices and some other stuff connected to it.

 

The switch in the attic is connected with a US 16 POE switch in my office. 3 computers are wired to that switch.
The connection between the two switches is a fiber connection through SFP 1 on both switches.
The software version is 5.07. I am not using VLANs, all ports are configured to ALL.

 

This configuration is working fine.

 

Today I decided to try to make a second connection between the switches, to use link aggregation. I set up a second connection between the two SFP 2 ports of the switches.
The setup was easy and everything seemed to be working fine.

 

Then an hour after setting this up I had to access the managent interface of a Synology NAS. The computer, connected to the switch in the office, told me it could not connect to the NAS..
The computer can reach the shares on the NAS, it can reach the webserver that runs on the NAS, but it cannot reach its management interface (which is a webinterface using port 5000).

The other two NAS devices show exactly the same behaviour.

 

I can reach the management interface of the NAS through WiFi, through a wired connection to the switch in the attic, but not with a wired connection to the switch in my office.

 

I disabled the link aggregation and the problem went away.

 

So my question is: Is link aggregation somehow blocking ports? Is this a bug?

 

SuperUser
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Re: Link aggregation between switches blocking ports?

Seems to be a common problem when trying LAG between multiple SFP ports.

 

@UBNT-Brandon or @UBNT-MikeD - any ideas?  This has to be the fifth or sixth person having problems with LAG over the SFP ports specifically.

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Having wifi problems? Take a look here first: https://help.ubnt.com/hc/en-us/articles/221029967-UniFi-Debugging-Intermittent-Connectivity-Issues-on-your-UAP
Ubiquiti Employee
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Re: Link aggregation between switches blocking ports?

This is strange.

 

To be sure: You do have link aggregation enabled on all 4 ports?  

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Re: Link aggregation between switches blocking ports?

[ Edited ]

Link aggregation enabled on SFP 1 and  SFP 2 port of US-48-POE switch (port 51 and 52) and link aggregation enabled on SFP 1 and  SFP 2 port of US-16-POE switch (port 17 and 18). So it is a link aggregation over 2 ports.

 

 

Regular Member
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Re: Link aggregation between switches blocking ports?

[ Edited ]

I have read in another thread that you need to hard reboot both switches after making the changes and re-adopting… and after that it will work.

 

https://community.ubnt.com/t5/UniFi-Routing-Switching/Small-edit-on-Unifi-switch-brought-network-dow...


Victor Bottacco
 Apple Consultant

Senior Member
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Re: Link aggregation between switches blocking ports?

I did reboot the whole network. Everything "seems" to be working, except that I can't reach the webinterface on port 5000 of the NAS.

 

 

Ubiquiti Employee
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Re: Link aggregation between switches blocking ports?

So I have a similar setup at home.  I ran into some issues during initial setup (which I wrote off as user error).

 

We'll try to reproduce in our test-labs to see what's going on here.

 

BR,

Brandon

 

P.S.: I'm running a Synology NAS w/ TimeCapsule backup (now for several months) over this interface and all seems OK.  Not quite sure the difference in your environment.

Want to try out new features or fixes before they're released as Stable? Sign up for Beta here: https://help.ubnt.com/hc/en-us/articles/204908664-How-To-Signup-for-Beta-Access
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Re: Link aggregation between switches blocking ports?

[ Edited ]

Thanks for looking into this.

 

The strange thing is that:

 

- Network connections with the Synology work (both with Windows PC and Mac). So for me TimeMachine is also working.

- I can access a website running on the NAS.

 

The only problem I have is that I am not able to access the DSM interface of the NAS from the US-16-POE switch through the link. I tried this on a Windows PC and a Mac.

 

I ran out of time this weekend so I did not try too many things to troubleshoot, I reverted to a single link over SFP 1. 

 

 

 

 

 

 

New Member
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Re: Link aggregation between switches blocking ports?

I have a very similiar situation with pretty much the same problem!

 

Freenas <4 1gig LACP Aggregate> 48 US POE Switch <> rest of the house wired connections and APs

 

- no VLANS

- all ports set to ALL

- ports 43-46 set to normal Aggregate mode

 

My laptop is wired to the same switch. I CAN ping the FreeNAS ip, cannot open CIFS shares on it and cannot open the web gui over port 80. 

 

I can access the freenas web gui from my cell phone over wireless and my girlfriend's laptop over wireless.

 

In troubleshooting, I disconnected the wired connection to my laptop and joined it to wireless. Now from the same laptop it can browse the FreeNAS shares and management interface just fine. Is there a bug in the LACP implementation that messes up TCP connections?

New Member
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Re: Link aggregation between switches blocking ports?

Adding to that, the FreeNAS web server shows the get requests from my laptop when it is wired, but I get no replies

Member
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Re: Link aggregation between switches blocking ports?

Did this get fixed?
Senior Member
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Re: Link aggregation between switches blocking ports?

Yes, this has been fixed long ago. Problem was that Jumbo frame settings were not applied to LAG connections.

Member
Posts: 138
Registered: ‎09-29-2016
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Re: Link aggregation between switches blocking ports?

Awesome thanks, I'm soon to set up a very similar network Man Happy
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