serv
Forum Maven
Networking FAQ and Troubleshooting Guide
Parallels Desktop Networking FAQ and Troubleshooting Guide
NOTE: this FAQ was written for builds prior to 1966. As of 1966 Parallels Desktop has "Shared Networking" mode. This mode is preferred over Host-Only with Internet Sharing and is much simpler to set up.
The Basics
Parallels Desktop provides four basic network configurations:
The small print provides some additional technical detail that you don’t have to understand.
. Bridged to Built-in Ethernet Adapter
One last thing is Default bridging. This simply bridges either to Ethernet Adapter or to AirPort depending on which one is active and has higher priority set in MacOSX Network Preferences.
Which configuration should I choose?
. If you’re in an office or at home with local network available you should normally choose Bridged Network to Ethernet or to AirPort. However if you need nothing more than sharing documents between VM and the Mac you may choose Host-Only as well.
. If you’re in a hotel room, in a restaurant or on a flight where charges are per IP address used, simply choose Host-Only w/ Internet Sharing.
. If you have no network connection in your Mac or are concerned about security of your VM, use Host-Only Networking. This will limit network communication of a VM to Mac only.
When in doubt try different configurations to see which one works or consult your Network Administrator.
How to turn on Internet Sharing
1. Open “System Preferences†and click “Sharing†in “Internet & Network†section
2. Select “Ethernet Adaptor (en2)†from “To computers using†list. Note that System Preferences shows Parallels Host-Guest Adapter as “Ethernet Adaptor (en2)†in this case.
3. Select the adapter you want sharing from in “Share your connection from†dropdown
4. Click “Start†button and confirm staring the service
How do I configure my guest OS?
You should generally use DHCP, Windows and Linux do it by default. If you know what you’re doing you may assign IP address and network mask manually, but you better be sure you’re allowed to.
Yikes! No network in my VM!
The simple solution is to consult your Network Administrator. Quite seriously! The network is an infrastructure and it’s her mission to keep it healthy. Do you always set up new computers yourself? If not, please, seek for help, because a new virtual machine is just like new computer to the network. Well… I assume you’ve already tried those four configurations above, did you?
How to pin down bridged network problems yourself
Let’s say your VM is in bridged mode, your guest OS is configured via DHCP but you can’t open your favorite web page in a browser. Here’s a check list to follow:
. Check your MacOSX network connection by opening, say, www.parallels.com in Safari.
. Open Terminal application in MacOSX and issue “ifconfigâ€. Note IP addresses of Ethernet Adapter (which shows as en0) and/or AirPort (shows as en1).
. Open a Terminal in the guest OS and issue “ipconfig /all†on Windows or “ifconfig†on Linux/BSD/Solaris. Check guest OS IP address: if no address shows up, or the address shows as 0.0.0.0 or as some address too different to what MacOSX indicates or if guest OS IP matches exactly MacOSX IP address, proceed to DHCP Problems section.
. Assuming your VM has got valid IP address check if you can ping machines on the local network from the guest OS by issuing “ping <address>â€. If you can successfully ping the Mac, some other machine on the network but not the router see Router Problems section.
. Try pinging your VM form the Mac and from some other machine on the local network. If the VM doesn’t respond try disabling firewall in the guest OS.
. Now try pinging some external site. If you see no responses proceed to Router Problems section.
If everything works OK till this point your problem may not be directly related to Parallels Desktop. It’s now time to meet your Network Administrator.
DHCP Problems
DHCP and Bridging to Ethernet Adapter
A DHCP server may be configured to assign IP addresses only to clients which hardware addresses are listed on the server. Talk to your Network Administrator to make appropriate changes to the server configuration to resolve this issue.
Also note that each time a new VM is created it’s assigned a new hardware address. You can change hardware address manually on the Advanced tab of VM Network Adapter Configuration should you need to do so.
DHCP and Bridging to AirPort
Some DHCP servers (including those embedded into Wireless routers) may refuse to assign an IP address to a VM bridged to AirPort or worse return the same address assigned to the Mac. One reason may be merely a server configuration issue, in which case you should visit your Network Administrator. The other possible reason is that the server distinguishes clients by their hardware address instead of the client identifier as required by DHCP standard.
To work around this problem assign IP address to the VM statically or use Host-Only Networking with Internet Sharing.
Router Problems
An advanced router may be configured to restrict outbound access based on machine hardware and/or IP address. Since your VM is acting like a new machine it should be assigned explicit permissions by router administrator.
Parallels Desktop Networking FAQ and Troubleshooting Guide
NOTE: this FAQ was written for builds prior to 1966. As of 1966 Parallels Desktop has "Shared Networking" mode. This mode is preferred over Host-Only with Internet Sharing and is much simpler to set up.
The Basics
Parallels Desktop provides four basic network configurations:
The small print provides some additional technical detail that you don’t have to understand.
. Bridged to Built-in Ethernet Adapter
This works as if your VM were a separate PC plugged into the network. This configuration is most compatible and transparent.
Bridging to Built-in Ethernet takes advantage of wired ethernet capability to “spoof†hardware address, i.e. to send frames with VM hardware address through Mac ethernet adapter.
. Bridged to AirPort AdapterThis mode works as if MacOSX were configured to have one more IP address and that address being handled by your VM. Note that wireless security (WEP/WPA) is handled by MacOSX, no additional configuration is needed in guest OS.
Due to limitations of 802.11 standard which is implemented by AirPort it’s not possible to spoof hardware address in this configuration. Ethernet frames sent from the VM have Mac AirPort hardware address on them.
. Host-Only NetworkIn this mode your VM is attached to a private network accessible by MacOSX but invisible to the outside world and can not access outside world either, but… read on.
Host-Only network is implemented by bridging to Parallels Host-Guest Adapter which is a virtual Ethernet adapter installed with Parallels Desktop.
. Host-Only Network with Internet SharingThis mode provides your VM with outside network access while still not allowing external access to guest OS. On the positive side of this mode is the possibility to share Bluetooth Modem or VPN connections from your Mac to a VM.
Internet Sharing in MacOSX is merely a NAT service supported by DHCP server and DNS proxy configured with a click of a mouse.
One last thing is Default bridging. This simply bridges either to Ethernet Adapter or to AirPort depending on which one is active and has higher priority set in MacOSX Network Preferences.
Which configuration should I choose?
. If you’re in an office or at home with local network available you should normally choose Bridged Network to Ethernet or to AirPort. However if you need nothing more than sharing documents between VM and the Mac you may choose Host-Only as well.
. If you’re in a hotel room, in a restaurant or on a flight where charges are per IP address used, simply choose Host-Only w/ Internet Sharing.
. If you have no network connection in your Mac or are concerned about security of your VM, use Host-Only Networking. This will limit network communication of a VM to Mac only.
When in doubt try different configurations to see which one works or consult your Network Administrator.
How to turn on Internet Sharing
1. Open “System Preferences†and click “Sharing†in “Internet & Network†section
2. Select “Ethernet Adaptor (en2)†from “To computers using†list. Note that System Preferences shows Parallels Host-Guest Adapter as “Ethernet Adaptor (en2)†in this case.
3. Select the adapter you want sharing from in “Share your connection from†dropdown
4. Click “Start†button and confirm staring the service
How do I configure my guest OS?
You should generally use DHCP, Windows and Linux do it by default. If you know what you’re doing you may assign IP address and network mask manually, but you better be sure you’re allowed to.
Yikes! No network in my VM!
The simple solution is to consult your Network Administrator. Quite seriously! The network is an infrastructure and it’s her mission to keep it healthy. Do you always set up new computers yourself? If not, please, seek for help, because a new virtual machine is just like new computer to the network. Well… I assume you’ve already tried those four configurations above, did you?
How to pin down bridged network problems yourself
Let’s say your VM is in bridged mode, your guest OS is configured via DHCP but you can’t open your favorite web page in a browser. Here’s a check list to follow:
. Check your MacOSX network connection by opening, say, www.parallels.com in Safari.
. Open Terminal application in MacOSX and issue “ifconfigâ€. Note IP addresses of Ethernet Adapter (which shows as en0) and/or AirPort (shows as en1).
. Open a Terminal in the guest OS and issue “ipconfig /all†on Windows or “ifconfig†on Linux/BSD/Solaris. Check guest OS IP address: if no address shows up, or the address shows as 0.0.0.0 or as some address too different to what MacOSX indicates or if guest OS IP matches exactly MacOSX IP address, proceed to DHCP Problems section.
. Assuming your VM has got valid IP address check if you can ping machines on the local network from the guest OS by issuing “ping <address>â€. If you can successfully ping the Mac, some other machine on the network but not the router see Router Problems section.
. Try pinging your VM form the Mac and from some other machine on the local network. If the VM doesn’t respond try disabling firewall in the guest OS.
. Now try pinging some external site. If you see no responses proceed to Router Problems section.
If everything works OK till this point your problem may not be directly related to Parallels Desktop. It’s now time to meet your Network Administrator.
DHCP Problems
DHCP and Bridging to Ethernet Adapter
A DHCP server may be configured to assign IP addresses only to clients which hardware addresses are listed on the server. Talk to your Network Administrator to make appropriate changes to the server configuration to resolve this issue.
Also note that each time a new VM is created it’s assigned a new hardware address. You can change hardware address manually on the Advanced tab of VM Network Adapter Configuration should you need to do so.
DHCP and Bridging to AirPort
Some DHCP servers (including those embedded into Wireless routers) may refuse to assign an IP address to a VM bridged to AirPort or worse return the same address assigned to the Mac. One reason may be merely a server configuration issue, in which case you should visit your Network Administrator. The other possible reason is that the server distinguishes clients by their hardware address instead of the client identifier as required by DHCP standard.
To work around this problem assign IP address to the VM statically or use Host-Only Networking with Internet Sharing.
Router Problems
An advanced router may be configured to restrict outbound access based on machine hardware and/or IP address. Since your VM is acting like a new machine it should be assigned explicit permissions by router administrator.
