Connection fails during large consecutive data transfers

[nyerup]

Hi,

My Viscosity client (on Mac) reproducibly fails, when I attempt to upload larger amounts of data (more than a few MB, I'm unsure about the actual limit) through the VPN connection. When it fails, I see the following in the Viscosity log:

Code: Select all

Feb 27 11:07:03: write UDPv4: No buffer space available (code=55)
Feb 27 11:07:03: write UDPv4: No buffer space available (code=55)
Feb 27 11:07:03: write UDPv4: No buffer space available (code=55)
Feb 27 11:07:03: write UDPv4: No buffer space available (code=55)
Feb 27 11:07:03: write UDPv4: No buffer space available (code=55)
Feb 27 11:07:03: write UDPv4: No buffer space available (code=55)
Feb 27 11:07:03: write UDPv4: No buffer space available (code=55)
Feb 27 11:07:03: write UDPv4: No buffer space available (code=55)
Feb 27 11:07:03: write UDPv4: No buffer space available (code=55)
Feb 27 11:07:03: write UDPv4: No buffer space available (code=55)
Feb 27 11:07:03: write UDPv4: No buffer space available (code=55)
Feb 27 11:07:03: write UDPv4: No buffer space available (code=55)
Feb 27 11:07:03: write UDPv4: No buffer space available (code=55)
Feb 27 11:07:03: write UDPv4: No buffer space available (code=55)
Feb 27 11:07:03: write UDPv4: No buffer space available (code=55)
Feb 27 11:07:03: write UDPv4: No buffer space available (code=55)
Feb 27 11:07:03: write UDPv4: No buffer space available (code=55)
Feb 27 11:07:03: write UDPv4: No buffer space available (code=55)
Feb 27 11:07:03: write UDPv4: No buffer space available (code=55)
Feb 27 11:07:04: write UDPv4: No buffer space available (code=55)
Feb 27 11:07:04: write UDPv4: No buffer space available (code=55)
Feb 27 11:07:04: write UDPv4: No buffer space available (code=55)
Feb 27 11:07:04: write UDPv4: No buffer space available (code=55)
Feb 27 11:07:05: write UDPv4: No buffer space available (code=55)
Feb 27 11:07:05: write UDPv4: No buffer space available (code=55)
Feb 27 11:07:05: write UDPv4: No buffer space available (code=55)
Feb 27 11:07:05: write UDPv4: No buffer space available (code=55)
Feb 27 11:07:05: write UDPv4: No buffer space available (code=55)
Feb 27 11:07:05: write UDPv4: No buffer space available (code=55)
Feb 27 11:07:05: write UDPv4: No buffer space available (code=55)
Feb 27 11:07:05: Disconnecting due to "No buffer space available" errors.
Feb 27 11:07:05: write UDPv4: No buffer space available (code=55)

I'll appreciate any help in debugging this.

J.

[James]

Hi nyerup,

As this is happening when you start to upload data my guess would be that the VPN connection is dropping when this occurs, causing the interface buffer to fill up (as packets can't be sent, but for UDP connections OpenVPN doesn't know the VPN connection has actually dropped until a ping-restart timeout is reached). Your ISP may be terminating the connection, or something else could be at play.

My recommendation would be to try switching to TCP and see if you see the same behaviour. If you do other factors that cause No buffer space available messages to consider include:

1. A problem with Mac OS X's network stack. Rebooting your computer will usually solve this.

2. A bad routing setup for your VPN connection. If one or more of the routes for your VPN connection clash it can result in such errors. These include routes set locally in Viscosity and those pushed out by the VPN server. In these instances you should get in touch with your VPN administrator.

3. Firewall or other network security software is preventing network traffic from being sent. In this case if you have any network security software try temporarily disabling it and see if it resolves the problem for you.

Cheers,
James

[xBlack]

I'm also running into this issue.

Code: Select all

write UDPv4: No buffer space available (code=55)

1. I tried restarting and the issue persists.
2-3. I can connect to the same VPN on Windows using the official OpenVPN client.

I'm on 10.10.2 with Viscosity 1.5.4.

[SpookyCow]

Same here but, I'm being told basically, oh well.