Using multiple network ports not recommended??

[koifish59]

So one of the stickies written by jgreco (HERE) says that using multiple interfaces on the same subnet is a big no-no. The thread is locked, so I'm asking here.

I have a server motherboard that has two 1gb ethernet ports. So I need to disable one of the ports in the BIOS to avoid this multiple interface problem? If it's not recommended to use more than 1, then why is there an option to add more than 1 interface in the GUI?

Also, perhaps something unrelated, I tried configure these two ports for link aggregation, but in the GUI, it does not list any of the network interface at the screen where I have to choose two. Why is this so, and how to fix?

 

[DrKK]

By "aggregation" you are probably thinking of LACP, which we don't recommend that home users use as it required equipment that is far fancier than the average home user has. If you only use one port, which is what I recommend, then you don't need to disable the other one. As long as you have nothing hooked to it, it's as good as disabled.

If, however, you would like to use multiple ports for any reason, the only safe thing to do really, in your shoes, is this:

https://forums.freenas.org/index.ph...failover-on-your-x10-or-similar-server.39366/

 

[jgreco]

You can add as many interfaces as you like. They just can't be on the same subnet unless you use LACP. Well, actually, they can even be on the same subnet without LACP, but they won't work the way you expect if you do, and then some other stuff can mysteriously break. But you can absolutely add as many interfaces as you can cram into a modern machine and have them all on different subnets. The LACP failover thing is okay too. Note that your switch needs to support LACP for any LACP option to be assured of working correctly.

 

[koifish59]

Yes, link aggretation/teaming is what I'm referring to. This is actually for a small business, and our switches here support 802.3ad. However, I don't even see my two network interfaces show up in the GUI section of Link Aggregation. Here's the screenshot. You can see clearly that I do have 2 ports configured and working, but I can't select them from available list in the Aggregation screen.

http://screencast.com/t/iyni1rYZrHZ


Anyways, so even though there is options for LACP and multiple interfaces, I should just unplug one port and only run on one?

 

[jgreco]

Yes, link aggretation/teaming is what I'm referring to. This is actually for a small business, and our switches here support 802.3ad. However, I don't even see my two network interfaces show up in the GUI section of Link Aggregation. Here's the screenshot. You can see clearly that I do have 2 parts configured and working, but I can't select them from available list in the Aggregation screen.

http://screencast.com/t/iyni1rYZrHZ


Anyways, so even though there is options for LACP and multiple interfaces, I should just unplug one port and only run on one?

What kind of switch do you have?

 

[Hugo Ochoa]

I'm interested in using link aggregation with the NETGEAR Nighthawk X8 R8500. I'm currently using a Netgear R7000 which is getting a bit overloaded for my use (4 hd WiFi cameras, 3-6 mobile phones (gest network), 4 laptops, PS3 through a Linksys WUMC710 Wi Fi AC, 2 DirecTV genie, wired gaming PC and FreeNAS). The NAS can be used for backups and streaming HD video at any time so I figured link aggregation could help speed things up. I'm wondering if my FreeNAS motherboard (MBD-X9SCM-F-O) does support link aggregation and if it would be cheaper to just buy a switch like the LINKSYS LGS308 ($85 newegg). My main concern is that connecting such switch to my R7000 would be done via 1 gigabit port which would (in my eyes) be the same as connecting it directly to my FreeNAS using the same gigabit port. Maybe I'm missing something but in my noob mind it would seem like the R8500 would be able to serve my WiFi clients better than a R7000 + LINKSYS LGS308 configuration even though the latter would be cheaper. Any thoughts?

 

[tvsjr]

You need to start by evaluating all that crap you have hanging off your WiFi. WiFi is not a replacement for wire... things like cameras, PS3s, DirecTV Genies, etc. should be hardwired. Your speed limitation is undoubtedly on the wireless side.

Link aggregation only helps you when making connections to multiple devices. You can bond 16 gig interfaces together... from your FreeNAS system to your gaming PC, for instance, you're still only getting 1Gbps.

 

[jgreco]

You need to start by evaluating all that crap you have hanging off your WiFi. WiFi is not a replacement for wire... things like cameras, PS3s, DirecTV Genies, etc. should be hardwired. Your speed limitation is undoubtedly on the wireless side.

Link aggregation only helps you when making connections to multiple devices. You can bond 16 gig interfaces together... from your FreeNAS system to your gaming PC, for instance, you're still only getting 1Gbps.

This is very wise advice. Link aggregation isn't likely to help a problem that is essentially a too-busy wireless network.

 

[BillCardiff]

Maybe he has those new fancy cordless phones :D

 

[jgreco]

Maybe he has those new fancy cordless phones :D

Are they wifi phones? ;-)

I'm kinda the opposite, fancy wireless network with almost everything wired anyways.

 

[koifish59]

What kind of switch do you have?

Sorry for such late reply. I had this project on hold for a while, but now back to it.

Anyways, switches we use are TP-Link SG108E (HERE), which supports link aggregation, but not the standard 802.3ad standard protocol like I had initially thought it would. So I'm assuming this switch can still be used with the freenas and use two of the ports on the motherboard, right?

 

[jgreco]

You can plug in two ports but it won't do what you probably want/think, so, no.

https://forums.freenas.org/index.php?threads/multiple-network-interfaces-on-a-single-subnet.20204/

 

[koifish59]

So if we're not suppose to use multiple interfaces in FreeNAS, when why is Link Aggregation even an option in the GUI? Are the developers not aware of limitation?

And in case one port or ethernet cable fail, how can I achieve some form of redundancy if we can't use two interfaces?

 

[Mirfster]

And in case one port or ethernet cable fail, how can I achieve some form of redundancy if we can't use two interfaces?

You can use failover mode for the link aggregations.

I tried configure these two ports for link aggregation, but in the GUI, it does not list any of the network interface at the screen where I have to choose two

You are not seeing the options to select the interface(s) because you already added the interface (under [Network] - [Interfaces]). When I setup my system(s); I configure the Link Aggregation(s) first (which I usually do at the physical console), then you will have the option to select the physical interface(s); once all that is done it then the item will automatically show up under [Interfaces]

Of course all of this is explained in the thread by @DrKK ; I am just summarizing :D

 

[anodos]

So if we're not suppose to use multiple interfaces in FreeNAS, when why is Link Aggregation even an option in the GUI? Are the developers not aware of limitation?

And in case one port or ethernet cable fail, how can I achieve some form of redundancy if we can't use two interfaces?

LACP works fine if you have a switch that supports it. The problem is that you need a lot of clients. If you only have one or two you won't see any benefit. As far as switches that support it, I've seen some cheap switches that claim to support it but their implementation appears broken. So YMMV.

 

[jgreco]

So if we're not suppose to use multiple interfaces in FreeNAS, when why is Link Aggregation even an option in the GUI? Are the developers not aware of limitation?

And in case one port or ethernet cable fail, how can I achieve some form of redundancy if we can't use two interfaces?

Because a link aggregation is a single interface as far as the UNIX system is concerned, of course. The underlying hardware implements it as several channels. This is not really much different from how a 40Gbps ethernet is actually physically 4x10GbE.

Using multiple interfaces on a single ethernet segment is not supported. It may "work" for some version of "work" that is not what you expect. Using a link aggregation on a single ethernet segment is definitely supported, but may still not be doing what you're expecting it to. Please see the sticky you previously referenced. I don't mind getting you straightened out but I'd suggest you re-read the paragraph immediately preceding this one to make sure you've dispelled some of the inevitable terminology boggles.