bernard.huang
Level 1 (4 points)
Notebooks

Q: Macbook - Is there anyway to have 2 internet connection at the same time?

Hi,

 

  Want to know if it is possible to have 2 internet connections both working at the same time. Specifically, one connection used mainly for downloading, and the other one used for uploading.

 

  The origin of my question is this. We have an ADSL connection, which is fast for download, but very slow for upload.

  We also have  4G mobile internet dongle, Both download and upload is fast, but as we all know, using 4G data is expensive.

  So we want to use ADSL for download, then use 4G connection for upload.

  Is there such a thing? I've been googleing and searching youtube. I don't see any similar subjects.

 

  I know from Macbook System Preferences > Network, you can have wifi and ethernet both active. Are they both active at the same time?

MacBook Air, OS X El Capitan (10.11)

Posted on Sep 10, 2016 12:57 AM

by Csound1,Apple recommended
Csound1 Csound1
Level 9 (50,267 points)
Desktops
A:

No, it won't use 2 connections simultaneously

Posted on Sep 10, 2016 7:46 AM

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bernard.huang

Q: Macbook - Is there anyway to have 2 internet connection at the same time?

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  • Helpful answers

  • by OGELTHORPE,

    OGELTHORPE OGELTHORPE Sep 10, 2016 3:28 AM in response to bernard.huang
    Level 9 (52,118 points)
    Mac OS X
    Sep 10, 2016 3:28 AM in response to bernard.huang

    bernard.huang wrote:

     

      I know from Macbook System Preferences > Network, you can have wifi and ethernet both active. Are they both active at the same time?

    Do they both have the green indicator displayed?

     

    Ciao.

  • by kaz-k,

    kaz-k kaz-k Sep 10, 2016 7:45 AM in response to bernard.huang
    Level 5 (5,650 points)
    Desktops
    Sep 10, 2016 7:45 AM in response to bernard.huang

    No, you can't.

  • by Csound1,Apple recommended

    Csound1 Csound1 Sep 10, 2016 7:46 AM in response to bernard.huang
    Level 9 (50,267 points)
    Desktops
    Sep 10, 2016 7:46 AM in response to bernard.huang

    No, it won't use 2 connections simultaneously

  • by Camelot,

    Camelot Camelot Sep 11, 2016 5:32 PM in response to bernard.huang
    Level 8 (47,243 points)
    Mac OS X
    Sep 11, 2016 5:32 PM in response to bernard.huang

    The answers given so far are not actually correct, but there is a matter of perspective.

     

    First of all, it IS possible to have multiple connections active at a time. This is actually quite common in server environments, but there is nothing preventing any client from having multiple links active at the same time. The issue is entirely a matter of which one is used.

     

    Secondly, because of the way IP addressing/routing works, it is NOT possible (at least not without playing multiple games that are beyond 99% of the population) to have incoming connections use one path (e.g. DSL) while the remote connection uses a different path (e.g. 4G). It is, however, possible to have all traffic to/from a specific address to use a specific link.

     

    The OS uses a routing table to decide which network connection to use. When you attempt to connect to a remote device, the OS looks up the routing table to determine which interface/connection it should use. If there is no specific rule then it uses the default router address. The kicker here is that you can have only one default address.

     

    So in the case of active links to the DSL and 4G networks, you may have a default route that points to the DSL router, and that link will be used for all outgoing traffic that doesn't have a more specific route. To do what you describe you could add a route to the specific upload server to use the 4G router, then all traffic to/from that server will use the 4G link, leaving other traffic on the DSL connection.

     

    This does require a) knowing the IP address of the server(s) that you want to communicate with in this way, b) knowing your IP configuration for each link (DSL and 4G), and c) admin-level privileges on your system. If you have all that then you might be able to do what you want.