TrueNAS 13U1 - does not preserve LACP interface

[ikroumov]

My TrueNAS has 4 NICs . I am using the first NIC as a standalone for setup
I am configuring NIC2-NIC4 into a LACP configuration interface.
There are two issues:
- issue 1
the LACP interface cannot accept IP address on the same network as the standalone interface. It require an IP address from different network
- issue 2 -
Configuring LACP interface (via Web interface )with 3 physical NICs proceed with the creation of the LACP interface while looses connection to the main interface (the standalone) and LACP never finishes configuration. It is gone !

 

[Patrick M. Hausen]

You cannot have two interfaces with addresses from the same network. You should always have an even number of member interfaces in a lagg. And last, you are aware of the two step "Test", then "Save" process?

 

[Hellrazorx]

-Issue 1 I experienced the same problem. But I'm ALWAYS using two nics on the same subnet with a similar setup as yours. I don't know if it's a trick but here's what I do to be able to achieve it.
--Configure your LACP with a fixed ip address
--Enable the standalone nic with dhcp
here's proof:

I don't understand this limitation and what trouble it's trying to prevent us from.

But anyway, maybe this solution will be patched away eventually

Just redid the same two days ago on TN 12.0-U8 and it just works.

-Issue 2 In the process, have you ever chose the Standalone nic (maybe by mistake ONCE) to be part of NIC team?
I had my share of cold sweat once when I tried to Reassign an adapter to standalone use after it was on lagg interface.
-- The issue was the MAC adresss mirroring that kept sticking to it.
--- Had to change manually the mac of the adapter(s)
--- Kick all network configs and redo it.

 

[Patrick M. Hausen]

Yes, did that. Change primary adapter to LACP, then quickly change switch, too - worked. You can set the timeout between "Test" and "Save" to a couple of minutes in a situation like that.

And the limitation will not be patched, because it is fundamental to the workings of IP. You cannot have two interfaces in the same prefix/broadcast domain, period.

If you force it somehow (e.g. with DHCP) you are doing it wrong and you will have odd behavior sooner or later.

See this post for all the details:

Multiple network interfaces on a single subnet

We've had a number of people over the years bring up the topic of multiple network interfaces on a single subnet. Often done by Windows administrators or storage admins, where it works to varying degrees, this is sadly not proper IP networking practice. Multiple interfaces on a single network...

www.truenas.com

 

[Hellrazorx]

Yes, did that. Change primary adapter to LACP, then quickly change switch, too - worked. You can set the timeout between "Test" and "Save" to a couple of minutes in a situation like that.

And the limitation will not be patched, because it is fundamental to the workings of IP. You cannot have two interfaces in the same prefix/broadcast domain, period.

If you force it somehow (e.g. with DHCP) you are doing it wrong and you will have odd behavior sooner or later.

See this post for all the details:

Multiple network interfaces on a single subnet

We've had a number of people over the years bring up the topic of multiple network interfaces on a single subnet. Often done by Windows administrators or storage admins, where it works to varying degrees, this is sadly not proper IP networking practice. Multiple interfaces on a single network...

www.truenas.com

I agree, it's not ideal, but I have no choice for now, router needs to be replaced asap .

 

[ikroumov]

I did try LAG configuration with 2 NICs and IP on the same subnet with a standalone NIC on OMV, (Open Media Vault) and other NAS solutions and it worked well without any issue. TrueNAS cannot configure LAG and standalone on the same network. It must be something with FreeBSD or how TrueNAS handles the network

 

[sretalla]

I did try LAG configuration with 2 NICs and IP on the same subnet with a standalone NIC on OMV, (Open Media Vault) and other NAS solutions and it worked well without any issue. TrueNAS cannot configure LAG and standalone on the same network. It must be something with FreeBSD or how TrueNAS handles the network

You can't talk about 2 NICs on the same subnet and LAGG at the same time, it's not the same thing. Of course you can have 2 NICs on the same subnet with LAGG.

You really should read the linked post above which explains why it's not right to do it on any unix variant (whether the OS lets you or not).

And maybe an analogy to round it out:

It's just like drink-driving... We absolutely know that it can be done, but that some of the time bad outcomes happen.... we're just telling you not to drink and drive so you don't get bad outcomes, we're not saying it's impossible to do.