[OpenVPN home] [Date Prev] [Date Index] [Date Next]
[OpenVPN mailing lists] [Thread Prev] [Thread Index] [Thread Next]
Google
 
Web openvpn.net

Re: [Openvpn-users] RE: Scalability?


  • Subject: Re: [Openvpn-users] RE: Scalability?
  • From: Martijn Lievaart <m@xxxxxxx>
  • Date: Thu, 03 Mar 2005 22:09:42 +0100

James Yonan wrote:

In general, crypto accelerators focus on symmetric encryption (AES or
Triple-DES), secure hashes (SHA-x), and random number generation.  This
will accelerate the encrypted "conversation" that occurs after initial
authentication, but not necessarily the authentication process itself.

OpenVPN can take advantage of all of these features in both SSL/TLS and static key mode, as long as the crypto accelerator is supported by OpenSSL (OpenSSL has a plugin capability where drivers for different crypto accelerators can be supplied as shared objects).





Thanks. So OpenVPN will benefit from hardware encryption with static keys on connection setup where it will not benefit when using PKI.


My servers cost much less than E600, but then I have to pay for them
myself. Still, as long as you don't have hunderds of users (I have 5) you
can provide professional quality service. Only the Internet link will
remain a SPOF, the rest will be redundant before long.



Speaking of redundancy in the internet connection, the new multi-homed patch for 2.0 that was discussed recently on the list will let you do something like host two redundant OpenVPN servers, and have each server be multihomed to two separate ISPs.

That would eliminate both the OpenVPN server machine and the internet connection from the set of server-side SPOFs.


I''m thinking of going one better. I probably can get a set of IPs from a /24 (one would be enough for OpenVPN but I need more for other reasons). Use RIP or OSPF and IPIP to tunnel that to home over two consumer DSL connections. That way the IPs I get from the /24 are always routed to my home. I'll use linux-ha to make stuff fail-over, so my incoming connections always get routed to a live box. I'll probably run into mtu issues, but I'll tackle that as it occurs. I already have ran with an artificially lowered mtu some time ago to investigate pmtu blackholes, so I know what I'm up against, I just still don't completely understand OpenVPN combined with LZO compression and fragmentation. What happens when I send full size packets over a VPN link? Does fragmentation happen and when? Maybe there is something worthwhile to be said about this on the site?


Now to find time to set it up..... :-(

M4