Tag Archives: default gateway

How Apple’s Bonjour service may break your net config…

Suddenly my brand-new, only a couple of days old Windows 7 installation had an odd problem: After a system boot or restart, networking would be broken in a way that hosts in the Internet could not be reached.

I investigated the problem and noticed that my Ethernet adapter had two default gateways assigned, while the first was

C:\Users\rabe>ipconfig /all
Ethernet adapter Local Area Connection:
   Default Gateway . . . . . . . . . :

I googled for this problem and found some hint that pointed toward’s Apple’s Bonjour service. Supposedly it sometimes starts up before networking is fully up, and in consequence assigns the invalid default gateway. The advice given there to solve the problem was to completely disable this service.

While I currently don’t need this service, I didn’t want to use this “brutal” approach, so what I did was switch the service to start up as Automatic (Delayed Start) as opposed to Automatic (which causes the service to start as early as possible).

And this indeed did the trick — I don’t have these annoying networking problems anymore. 🙂

Update: To correct the name in the “Services” application which will often be Id_String2.6844F930_1628_4223_B5CC_5BB94B879762 you can use a command sequence as follows (your path to mDNSResponder.exe may vary):

"C:\Program Files\Bonjour\mDNSResponder.exe" -remove
"C:\Program Files\Bonjour\mDNSResponder.exe" -install