mac pro ethernet 2 port not working

Discussion in 'Mac Pro' started by howard, Jan 20, 2008.

  1. howard macrumors 68020


    Nov 18, 2002
    I've discovered that my ethernet 2 port on my mac pro is not work. When i plug my internet into it it does not connect properly, when ethernet 1 works fine. But when i plug in the cable to ethernet 2 it does change the state in system preferences and reads that the connection has a self attained IP but may not be able to connect. This makes me think that its not a hardware problem, but I'm not sure.

    anyone else experience this or know what to do?

    ultimately I'm trying to connect a network backup drive, which seems to connect from ethernet 1, but again not from ethernet 2.
  2. Sergei macrumors newbie

    Jan 10, 2008
    possible solution

    I know this sounds unlikely, but often these issues can be fixed by simply unplugging your computer for a few minutes before plugging it back in and starting up. I would suggest giving it a try.
  3. Infrared macrumors 68000


    Mar 28, 2007
    What does it say if you type "ifconfig" in
  4. kps macrumors regular

    Jan 10, 2008
    Connect to what? Do you mean you have a DSL or cable modem on the other end of the cable, and you can't access the outside world?

    Yes, it's a configuration issue.

    Can you clarify what your network looks like? Is it correct to assume that you don't have a hub or switch, and you want to put your modem on one link and your NAS on the other?
  5. Sepharial macrumors newbie

    Jan 12, 2008
    Both my ports are working fine on my 2008 pm. One is for the internet and the other one goes to a writer.
  6. howard thread starter macrumors 68020


    Nov 18, 2002
    yes I was planning on putting my modem on 1 jack and the backup network drive on the other. I think the internet was not coming through on jack 2 cause I learned that road runner is set up to work with one jack and once its set up with that it won't work with the other on the same machine due to a different MAC address or something... just something I heard don't know if thats true.

    anyway, when I do try and connect my network drive on the jack 1 it at least shows up, and does not at all on jack 2. Ultimately I think i just need to get a router to hook that up to as I have had a hard time getting it an ip address that I can connect to.

    this is what it says after I type ifconfig:

    lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384
    inet6 fe80::1%lo0 prefixlen 64 scopeid 0x1
    inet netmask 0xff000000
    inet6 ::1 prefixlen 128
    gif0: flags=8010<POINTOPOINT,MULTICAST> mtu 1280
    stf0: flags=0<> mtu 1280
    inet6 fe80::217:f2ff:fe05:2472%en0 prefixlen 64 scopeid 0x4
    inet netmask 0xfffffc00 broadcast
    ether 00:17:f2:05:24:72
    media: autoselect (100baseTX <full-duplex,flow-control>) status: active
    supported media: autoselect 10baseT/UTP <half-duplex> 10baseT/UTP <full-duplex> 10baseT/UTP <full-duplex,hw-loopback> 10baseT/UTP <full-duplex,flow-control> 100baseTX <half-duplex> 100baseTX <full-duplex> 100baseTX <full-duplex,hw-loopback> 100baseTX <full-duplex,flow-control> 1000baseT <full-duplex> 1000baseT <full-duplex,hw-loopback> 1000baseT <full-duplex,flow-control>
    ether 00:17:f2:05:24:73
    media: autoselect status: inactive
    supported media: autoselect 10baseT/UTP <half-duplex> 10baseT/UTP <full-duplex> 10baseT/UTP <full-duplex,hw-loopback> 10baseT/UTP <full-duplex,flow-control> 100baseTX <half-duplex> 100baseTX <full-duplex> 100baseTX <full-duplex,hw-loopback> 100baseTX <full-duplex,flow-control> 1000baseT <full-duplex> 1000baseT <full-duplex,hw-loopback> 1000baseT <full-duplex,flow-control>
    lladdr 00:16:cb:ff:fe:70:53:86
    media: autoselect <full-duplex> status: inactive
    supported media: autoselect <full-duplex>
    inet netmask 0xffffff00 broadcast
    inet6 fe80::219:e3ff:fe09:513d%en2 prefixlen 64 scopeid 0x7
    inet netmask 0xffff0000 broadcast
    ether 00:19:e3:09:51:3d
    media: autoselect status: active
    supported media: autoselect
  7. supercooled macrumors 6502a

    Sep 6, 2007

    writer = printer?

    I actually don't know the immediate and practical use of a second LAN on a machine like this. Before the use of routers in the home were made pervasive, I had to add a second NIC card to share my internet with other computers via a HUB. Yeah.
  8. kps macrumors regular

    Jan 10, 2008
    That would explain what you see.

    You don't need to get a router; the Mac can act as one.

    First try turning on Internet Sharing in the Sharing settings, from Ethernet port 1 to Ethernet port 2. If that doesn't let your drive work on port 2, you will need to do some manual configuration of port 2 -- in that case, it might help to know what model NAS you have, in case it has some particular requirements.
  9. howard thread starter macrumors 68020


    Nov 18, 2002
    I tried that but the NAS still doesn't come up. (it still does on port 1).

    Its a Buffalo Terastation. I just found out that it apparently works best when it can automatically get assigned an IP through DHCP. Isn't it the router that does that?
  10. kps macrumors regular

    Jan 10, 2008
    Yes, typically, the router does that. With "Internet Sharing" turned on, the Mac should have been forwarding the DHCP between the NAS and router. However, typically, the router also doesn't care what ethernet port it's connected to. I am guessing that the router declined to provide DHCP service for the NAS, just as it declined to do so for the Mac port 2. If that is the case, adding an ethernet switch won't help you -- you would need a full-fledged IP router, and ones that do gigabit ethernet aren't cheap (you don't want to cut your disk access speed to 1/10 capacity).

    Connecting the NAS to the Mac's port 2 isn't a bad idea for your setup, since it will make the full 1Gb/s link available to disk traffic, without competition from internet traffic. You can set up the Mac to provide DHCP service for the NAS on port 2. However, I've never done this, so I can't tell you exactly how to do that.
  11. msealey macrumors newbie

    Feb 19, 2008
    Ports 1 and 2

    I think I may be having a similar problem: sometimes port 1 works and sometimes port 2; it's consistent across cable modem recycles.

    If I power-cycle the TW RoadRunner-supplied cable modem (and sometimes when I restart my Xeon Mac Pro, 10.5.2), they usually switch:The port that worked in the last session (that is, before the restart(s)) stops working while the one that typically gave the IP address assignment message you get then starts to work.

    I have a case open with the ever helpful Apple and am waiting to see if it's hardware... a new and pristine machine with no haxies etc., and permissions repaired daily etc.

    I tried it with another RoadRunner modem and got the same behavior.
  12. sandylp macrumors regular


    Jul 10, 2004
    San Francisco Bay Area
    Fixed It!

    I, too, had the problem with the ethernet port. It had a self assigned ip address. Apple has an article about it on this page: I found that it wasn't enough to turn the cable modem off and unplug everything connected to it. I had to take out the modem's battery, which was easy to do. Then I put the battery back and put back the cable, etc., went to system preferences (with that ethernet port connected ), Advanced, Renew DHCP lease and clicked OK...and it connected after a few seconds. :)

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