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Very slow UltraVNC when network adapters are combined with a virtual bridge

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mlei
Posts: 1
Joined: 2025-02-01 18:18

Very slow UltraVNC when network adapters are combined with a virtual bridge

Post by mlei »

I'm running UltraVNC Server on a PC with 2 Ethernet ports.
These ports are combined with a virtual bridge from Microsoft in Windows 11.
One of the port is connected to a laptop with 1 Gbit/s link to a laptop. The other port is not connected.
On the laptop there is a UltraVNC Viewer running.
The connection is established very quick but the response after connection when moving windows is very slow.
It takes up to 30 s to refresh.
If i disable the virtual bridge everything works fast.
Both PC and Laptop have Windows 11 with UltraVNC 1.4.3.6 with SecurePlugin enabled.
Any ideas why this happens?
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Rudi De Vos
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Posts: 7018
Joined: 2004-04-23 10:21
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Re: Very slow UltraVNC when network adapters are combined with a virtual bridge

Post by Rudi De Vos »

There are many posts on the net that sometimes virtual bridges are slow for tcp .
I'm not a bridge specialist but it seems to happen when there are routing issue's.

Google "virtual bridge microsoft slow"
Perhaps you understand the answers better
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