yet another newb question... what's the point of having two RJ-45 ports on a mobo?

Discussion in 'Motherboards' started by Turbonium, Oct 23, 2012.

  1. Turbonium

    Turbonium Golden Member

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    As the title says.

    Is it literally for hooking up to two separate networks at the same time? If so, what sort of environment would warrant the need to do this?

    Also: the motherboard I'm looking at actually has two different LAN controllers for each RJ-45 port. One of the ports is red, the other black. I'm assuming the black is the "regular" port. But still, why two different controller models?
     
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  3. Deaks2

    Deaks2 Member

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    Either to act as a bridge, or you bond both connections (ie: 2*GigE).
     
  4. Turbonium

    Turbonium Golden Member

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    I got so much to learn, lol.

    Thanks.
     
  5. kleinkinstein

    kleinkinstein Senior member

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    On the few boards I've had that had dual LAN ports, I never actually used both. Unless your WAN connection is greater than 2Gbps (or 200Mbps, if you've only got 10/100 ports), or you want to run a small cluster with several dual-port systems all running "teamed", having two ports is mostly useless, and just a false "feature" they can charge more for.

    It's not useful for the home bound consumer rig. It is really only useful for redundancy if one port has issues or if you have a very advanced network setup - two separate networks with the computer on both networks. Yet very rare outside of business servers which wouldn't generally use "normal" motherboards anyway.
     
  6. pauldun170

    pauldun170 Diamond Member

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    VM instance #1 assigned to physical NIC #1
    Host OS + Oracle instance bound to NIC # 2

    In the past I've setup Routing And Remote Access Services..
    I had one box with 6 nics in at one point.
    I can't even remember what the hell I was doing with it but I did need to have 6 nics installed at one point.
    Nowadays I don't have that kind of time on my hands.

    Having said that, when I get home I'm de3finitely going to play around with the ep45-udp3 + q9550 box I have set up as a vm host.


    p.s. Any want some PCI nic 100mb cards?
    I have a bajillion of them.
    lol
     
  7. BrightCandle

    BrightCandle Diamond Member

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    In the past I bonded them to get 2gbps. 1gbps is easily saturated with modern drives and I needed a lot more for uncompressed video.

    At work I mostly use them for different networks such as dev and production. So you can do backups without breaking the app. Very occasionally we use it for redundancy.
     
  8. Deaks2

    Deaks2 Member

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    I could use a bonded setup. My NAS has a 3 disk ZFS RAID5 array with a 30GB SSD cache and 8 GB of RAM. I can transfer a huge file before running out of cache and hitting the spinners...

    However, the most I ever send to it are BluRay rips, so it is more of a once off transfer.

    It is fun to watch the network counter showing sustained 115 MBps though.
     
  9. mv2devnull

    mv2devnull Senior member

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    First one is probably courtesy of the main chipset and the second by a third-party chip. There is variation on what is easy for the board makers to build "as default" and what they tag on top for the "more bells and whistles" models.

    Between two network segments can be either a bridge or a router. Bonding attempts to improve bandwidth or availability of a single "link". VM's were mentioned already.

    I do know of a setup, were two NICs form a bond and through that bond flows several VLANs, since VMs are on different networks. Another, a ga-ep45-dq6 with *four* builtin NICs serves as a bridge between single Gbps outbound three and three other network devices -- a switch on a budget. Neither setup is "home stuff".


    I did have a while a NAS with Gbps and a mere 100Mbps router/switch at home. It was better to hook the NAS to the net via PC that had two Gbps NICs.
     
  10. red454

    red454 Senior member

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    Good info - I always wondered about that too...
     
  11. piasabird

    piasabird Lifer

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    For most people there is no realistic use for having 2 ethernet ports.
     
  12. _Rick_

    _Rick_ Diamond Member

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    ...to daisy chain Gigabit Ethernet :O

    Actually, there's several other ways to use the second port:

    Dedicated remote management (vPro, IPMI...)
    Routing (hook up a dsl or cable modem)
    Redundancy (in case of cable failure, unplugging, port failure)
    Also you can use it to create two local networks and route between those, i.e. to manage a separate open wireless network, or even a closed guest network.
    Currently thinking about getting a third NIC for my next server, so I can have both a high performance internal port, and a dedicated vPro port as well as the WAN port.
     
  13. Wall Street

    Wall Street Senior member

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    I have two NICs on my board. One is a premium Intel chip that isn't supported by Windows 7 out of the box and requires you to install drivers from the net. The other is a Realtek chip that I used exactly long enough to download the Intel drivers and now sits idle because it has drivers embedded in the Windows 7 install disk.

    I concur that very few people can use both ports. However the same can be said for many motherboard connectors (Floppy connectors, IDE connectors, COM headers, multiple PCI slots) but motherboard makers need to put something because the boards won't look "premium" if it only supports the Intel chipset features.
     
  14. wpcoe

    wpcoe Senior member

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    When I has a mobo with two LAN ports, I used them both because I was lazy:

    I would use one port with file sharing disabled to connect to ADSL.

    I would use the other port with file sharing enabed to network with my other computers.

    With my current mobo with one LAN port, I keep enabling/disabling file sharing if I change use from ADSL to LAN. But, actually these days, I just use WiFi for my WAN access, and only use the LAN port for actual LAN file sharing, but it does address the OP's question about "what sort of environment would warrant the need to do this?"
     
  15. Sheep221

    Sheep221 Golden Member

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    The example use of 2 ports is in industrial setting, via one is computer connected to the LAN and internet and second port is used to control attached electro-mechanical system, such as assembly line or specific machinery, such as spindle, engraver and many more.

    Another advantage is to have the second port available in the case your first one fails.
     
  16. ericloewe

    ericloewe Senior member

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    Intel network chips requiring drivers not shipped with the OS? That's something I don't see everyday. Every OS I could imagine using has the Intel drivers.
     
  17. Alaa

    Alaa Senior member

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    I have 2 phone lines and each one can support 4Mbps ADSL connection. Can I combine both with 2 RJ45 ports and two ADSL routers/modems?
     
  18. GrumpyMan

    GrumpyMan Diamond Member

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    One for my cable modem and one for my PS3...
     
  19. mv2devnull

    mv2devnull Senior member

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    Probably. You will have to pay for two connections and configure routing somehow. The following example most likely does not work for you directly:
    http://lartc.org/howto/lartc.rpdb.multiple-links.html
     
  20. tweakboy

    tweakboy Diamond Member

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    My OG ASUS A7N8X E Deluxe had 2 Ethernet ports.... just like above says. One to act as bridge. gl
     
  21. CryHavoc

    CryHavoc Senior member

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    in the server world, two nics can be setup for Teaming with auto failover and for load balancing.

    In the gaming and home user world, very few would use the second one unless they have two separate networks or some other special setup.
     
  22. ash316

    ash316 Junior Member

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    Also, two ports are used in clustered server environments where fail over support is required. One port is connected to your network and other one two another system which keeps on sensing the other system (known as heart beat check). As soon as it detects that the other system is not responding, it takes the control and serves all the requests