Ethernet Link Aggregation W/ Thunderbolt Display

Discussion in 'Mac Accessories' started by ThisIsNotMe, Jun 15, 2013.

  1. ThisIsNotMe Suspended

    Aug 11, 2008
    Title says it all.
    Currently considering a 2012 iMac and 2 additional Thunderbolt displays.
    Curious if link aggregation works (for 3xGbE) through Thunderbolt.
  2. John Kotches macrumors 6502

    Jan 19, 2010
    Troy, IL (STL Area)
    Keeping in mind, I have not actually done this but...

    The link aggregation should have no dependence on whether it's thunderbolt or not.

    Don't forget your switch/switches must support link aggregation to make this work. However, unless you're doing lots of large transfers to disk arrays, the added expense of smart/managed switch isn't worth it.

    For me, the switch to jumbo frames was a big jump in and of itself.
  3. wserbia macrumors newbie

    Aug 1, 2013
    Thunderbolt Ethernet link aggregation totally works

    Just configured link aggregation on my MacMini with the built-in ethernet and a Thunderbolt ethernet adapter and it smoking fast. I was frustrated with 40-80MB-sec transfers to a Synology NAS that is link aggregated. Now I'm getting 90-170MB-sec transfer speeds while doing a 3TB+ TimeMachine backup.
  4. opinio macrumors 65816

    Mar 23, 2013
    I run aggregation through the Mac mini ethernet and a T-bolt adapter. It is very fast but only between devices running aggregation. You also need switches that support aggregation. I also found if the mini sleeps the aggregate link sometimes does not re-link. The T-bolt part of it doesn't re-link. I need to usually reboot. It is not so much of an issue for me though as I run my mini 24/7 with no sleep.
  5. longhuay macrumors newbie

    Aug 2, 2013
    I need to usually reboot. It is not so much of an issue for me though as I run my mini 24/7 with no sleep.[​IMG]
  6. mvmanolov macrumors 6502a

    Aug 27, 2013
    Opino, if i understand correctly, you have a mini with LAG, which feeds to a LAG enabled switch, and from there you a re connected to another machine again through LAG? and at this point, when you do a file transfer from one machine to the other, you can see the speed difference (200+MB/s)? did i get this right?
  7. opinio macrumors 65816

    Mar 23, 2013
    Yeah that is correct. But I gave up on it months ago because I never used the speed. Gigabit was enough. Plus, occasionally the tbolt adapter would lose its connecion so the aggregation would go down every few months or so.
  8. mvmanolov macrumors 6502a

    Aug 27, 2013
    Thank you, alternatively to increased user to user throughput you can use aggregation to increased overall multi-user throughput no?

    User 1 connected to mini can draw and the 100MB/s max
    simultaneously user 2 can do the same..
    (if user 1 and 2 are not on the LAG)

    Do i get this right?
  9. opinio macrumors 65816

    Mar 23, 2013
    I am resonably certain you are right.

    I ran two configs.

    One: With a 2012 Mac mini with aggregated link to a D-Link 8 port switch and the the other 2011 Mac mini connected aggregated to the switch. The speed was exceptional when writing on the SSD via Black Magic fromt he other mini. But since then Apple has introduced the T-bolt link which is similar to the aggregated link so perhaps my first config is only beneficial over a longer distance.

    The second config was with the 2012 mini once again aggregated to the Di-link switch, but all other Macs (two minis and two MBAs) connected via gigabit only to the switch. I tried multiple tests by running Black Magic from the 'workstation' Macs to read/write on the drives of the 2012 mini thereby using the network link. I made sure I used very fast drives to write to (1 SSD, one RAID-0 8TB 7200rpm, one RAID-0 6TB 7200rom drive). So I had plenty of writable and readable drives on the 2012 mini which could absorb the onslaught of data.

    So anyway it appeared the aggregated link allowed for the 'workstations' to read/write faster as the total on the numerous black magic tests (run simaltaneously) was well above 100MB/s. I roughyl got 105MB/s reading and writing across single gigabit. But the three 'work stations' were functioning in the 50-60s (times three is about 150MB/s).

    I think it really depends on your switch. YOu need to make sure it formally supports aggregation.

    But anyway, as I said. I found 99% of the time I did not use the aggregated link as it was rare to have two Macs writing simultaneously and using the full bandwidth of the link. So I only run on single gigabit now.

    Having said that, if you had a server that received a lot of network data, and had an exceltionally fast drive/s attached to it the it would be beneficial.
  10. mvmanolov macrumors 6502a

    Aug 27, 2013
    Sounds quite cool... I don't have any "reasonable" use for it, but did land a rather nice smart switch :D so it's more like wanting to try things out experiment and learn about networking. I'll run the mini in a LAG and see what happens :D

    And thanks, for the detail! I appreciate it :D
  11. opinio macrumors 65816

    Mar 23, 2013
    I am guessing you know how to set up the aggregate link but just in case:

    1. Make sure you have two or more ethernet connections connected to the Mac. For example 1 on-board gigabit ethernet link and 1 T-Bolt or USB3.0 gigabit ethernet adapter.
    2. Make sure they are both connected to the switch and are pulling an IP address each (i.e. set up as two standard gigabit connections to the Mac)
    2. Go to Network Settings.
    2. Click the drop-down settings box ('gear' icon next to the +- buttons) at the bottom of the network connection options window.
    3. Choose Manage Virtual Interfaces.
    4. Click + and New Link Aggregate.
    5. Highlight 2 or more links (I am assuming you will have only two though).
    6. Name the aggregate link. I used 'Dual Gigabit'.
    7. Click Create.

    The switch must support the IEEE 802.3ad (which I believe is now called IEEE 802.1ax). Generally the specs will say link aggregation is supported. If it is supported then the lights will go green at step 7 above, but if link aggregation is not supported then the lights will remain red. I say that because I found one switch that did support aggregation even though is was not set out in the specs.

    From memory you may need to reboot or wait a minute for the link (green lights) to become active (at point 7 when you click create).

    Also I remember that the IP address that is the lower of the two is the one used for the link. I say this in case you need to assign an IP from your router. In other words if one link is and one is then the IP for the aggregate link will be This is really only relevant if you use static IP addresses and you forward ports etc.

    Attached Files:

    • 1.jpg
      File size:
      29.3 KB
    • 2.jpg
      File size:
      28 KB
  12. mvmanolov macrumors 6502a

    Aug 27, 2013
    I didn't know that it takes the lower IP for the link... and that was important for me as i use static ip for the server. so thanks for that :D
    heh, just got my patch panel :D

Share This Page