Slow and intermittent connections to a SonicWall Pro 300

[ac3boy]

Hi,

First, thank you for creating this software. it was much needed.

I wass able to get the tunnel open from OS X 10.2.6 MDD 867 over a DSL line to the SW 300 through a T1.

Once the tunnel was open I was able to ping and connect to the local LAN without a problem. The 2 issues I was having is the tunnel going down very quickly, sometimes with traffic and sometimes with not. It was very intermittent but disintegrated quickly. One click of the vaporize button brought it right back up.

The second issue was speed. Using Timbuktu I did a speed test without the tunnel and was getting a solid 115K-120K/sec. With the tunnel I was getting only around 4K/sec and it was bouncing all all over the place. It was very very slow.

I would be glad to do more tests if I could get a little feedback. Please let me know what info you need from my configuration. I am basically using all the defaults in vapor on all tabs and on ID I am using address for local and remote.

Both the local and the remote network are using NAT.

This was tested on 2 different local networks on 2 different machines going to the same remote SonicWall.

Thanks in advance for any help you can offer.

Cheers, John.

[ac3boy]

I have the key negotiation set on 24 hours. I will test the on the DMZ port of the firewall and vpn in direct if I can. I did another speed test a bit ago with the SonicWall VPN client and it was very speedy. i immediately opened a tunnel with Vapor and it was extremely slow again.

I did close the other tunnel down before opening Vapor.

Any other ideas?

[opus]

It could be MTU, but I doubt it. I’d expect the Windows client to have the same behavior. You can adjust the Mac’s MTU using the terminal:

sudo ifconfig en0 mtu 1200

Enter an MTU value between 1-1500. You shouldn’t have to go any lower than 1000 or so.

Another way to test MTU is to send pings of varying size:

ping -s 1472 x.x.x.x

The max MTU for your connection is the ‘-s’ value + 28. Be sure to do this test through the VPN tunnel, because the IPSec headers added to the packet will decrease the actual packet size allowed.

What’s performing NAT on the SonicWALL side? Is it the firewall itself, or the router or some other device in front of it?

[Author]

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