osx - Mac OS X Lion cannot access a website, but another PC on the same network can - dns issue?

07
2014-07
  • Adam

    I have a Mac OS X Lion laptop and a Windows 7 machine on my network. I can access a website from one, but not the other. When I try and access this website from my Mac Safari says it cannot find the server. I have Chrome installed on the same machine and it cannot find it either.

    I checked the DNS settings, adding a couple more servers to the list but this didn't help (I reordered them so I knew it was using a new DNS server).

    I also flushed the DNS cache using the following command in terminal:

     dscacheutil -flushcache

    That did nothing. Finally I cleared the cache in Safari, that did nothing.

    Any ideas? I had a problem with this host before putting my IP on a backlist, which I was able to confirm by going through a proxy - but this time the Windows PC is okay, and they are both behind the same router and same IP.

    • Answers
  • Adam

    Turns out it was a DNS issue on the domain side. Still dont understand why one computer could access and another one could not. I would have thought a DNS issue would have prevented all from accessing.


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    networking - How do I get SSH access to a Mac, connected to another Mac by Ethernet, from a MacBookPro on the same network?
  • i0n

    Ok, so the scenario is this:

    I have a G5 Quad (running Leopard) with no wireless card. The G5 is connected by Ethernet to a Mac Mini (running Lion), which is picking up my AirPort Extreme network over WiFi. The Mac Mini shares its internet connection over Ethernet to the G5, enabling it to connect to the internet perfectly. I can also screen share or SSH into the G5 from the Mac-Mini without any problems.

    Now comes the trouble:

    I have a MacBook Pro (running Lion) which also connects to the same WiFi network as the Mac Mini. I can see (and connect to) the Mac Mini from the MBP without trouble, but I cannot see or connect to the G5 from the MBP.

    How can I configure this so that I can SSH or screen share the G5 from my MBP?

    IPs and subnets of machines:

    • Mac Mini IP: 10.0.0.9
      Subnet Mask: 255.255.255.0

    • MBP IP: 10.0.0.4
      Subnet Mask: 255.255.255.0

    • G5 IP: 192.168.2.3
      Subnet Mask: 255.255.255.0


    • Related Answers
  • slhck

    Port forwarding VNC

    If you use VNC for screen sharing it should be easy to just tunnel the port through the Mac Mini. So, from the MacBook Pro, you'd call:

    ssh -L5900:192.168.2.3:5900 10.0.0.9

    … where:

    ssh -L<local-VNC-port>:<IP-of-G5>:<port-of-screensharing-at-G5> <IP-of-Mac-Mini>

    This way, you'll have to actually connect to your localhost:5900 from the MacBook Pro (e.g. using Chicken of the VNC or a similar program).

    SSH Proxy

    If you can SSH from your Mac Mini to the G5, and from the MBP to the Mac Mini, then all you need is to "hop" over the Mac Mini to SSH to the G5 directly.

    On your MacBook Pro, edit the file ~/.ssh/config (create it if it doesn't exist). Add the following:

    Host g5
  User <username-for-Mac-Mini>
  HostName <hostname-of-Mac-Mini>
  ProxyCommand nohup ssh <hostname-of-G5> %h %p

    The next time you want to connect to your G5, just call ssh g5. You will be directly connected to the G5. You could replace the host names with IPs too, if you like.