This is a really odd issue. When connected to corporate VPN all http requests are normal and as expected. When not on vpn using either my laptop, desktop, or ipad all http requests appear to be extreamly sluggish. My network topology is a linksys WRT310, and a ubee modem, all set to stock settings, thoughts? I am thinking it should be impossible for the VPN to run faster than the native connection it is using.

  • Could be slow DNS on your connection, and when your on vpn- it's using your company DNS which is much quicker. Try some tracert's.
    – AliGibbs
    Apr 20 '12 at 13:15
  • OK the actual problem turned out to be there was something running on all my systems using up resources, when vpn was engaged firewall blocked it thus increasing output of my connection. My ipad is an ipad 3 so I think it is just running slow because of the new ipads wifi problems since I tried it on another connection and it had the same issues. Thank you everyone for your input, great stuff! Apr 20 '12 at 14:40

The only things that should affect your web browsing over what should be a slower connection (the VPN) actually being faster than when you're disconnected would be a proxy server and/or DNS.

Check if you're using DNS over the VPN compared to responses when disconnected. It's possible your work DNS is faster than whatever you're using without the VPN.

The proxy one might be possible, but really should be a remote possibility.

(Use a packet sniffer to help determine what is happening with timing on your DNS lookups, or use nslookup or similar tool to see where your requests are defaulting.)

  • It's also possible that the work DNS is left as the preferred DNS when the VPN no longer is on and DNS requests time out before falling back to the normal DNS server.
    – ptman
    Apr 20 '12 at 13:22
  • @ptman - good point, depending on how the VPN client is implemented. Apr 20 '12 at 13:23
  • Theoretically the VPN connection can also be faster even if the problem doesn't lie with DNS. When cryptography is done right, data is first compressed and only then encrypted. So the VPN may end up transferring less data in the end. But this is all very theoretical.
    – ptman
    Apr 20 '12 at 13:25
  • I would have thought the act of encrypting would affect the average speed along with the load on the CPU doing it; at first I thought the compression could affect it but then I thought better of it. Plus once it reaches the endpoint, you're pulling data back through at "normal" speeds from your employer's end, any boost would just be at the vpn points. Apr 20 '12 at 13:33
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    They could also be using proxy servers, caching, acceleration devices, etc. Apr 20 '12 at 14:15

Since a VPN connection locks off several ports that are normally available, my first thought is that you have service running that might be hogging your regular bandwidth. If this is the case and the VPN tunnel shuts off these ports, it might explain how the request are answered faster.

Have you tried monitoring your network traffic on the iPad when your VPN tunnell is open on the desktop versus when not in VPN?


I doubt this accounts for it, but one feature of a VPN is to encrypt the traffic passing through, and one side-effect of encryption is that the encrypted data is often compressed. Therefore, you're sending slightly less data through the connection, which means it can complete requests faster.

  • Depending on the content and nature of the material, the benefits of the compression may/should average out. If OP is web browsing outside of work, the compression only benefits for one leg of the trip through however many hops the VPN covers. The rest still depends on requesting and pulling information from the employer's (uncompressed) connection, then getting encrypted and compressed and sent back to you. Apr 20 '12 at 14:21

Some VPNs offers compression, if you are downloading compressable data - your VPN connection may be faster than native. Also, it's possible, that after your router there's some big router that can shape your speed using QoS - VPN trafic can have bigger priority than your direct connections.

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