VPNs are the United Nations of computing: Important people who don't know what's going on sit around waiting for their fellow countrymen to translate into their ear-pieces because the technology is no good in real time. And that's when everyone in your organization runs Windows! Throw in other operating systems, and you've got yourself a support nightmarebut it doesn't have to be that kind of world. Free Secure Wide Area Network (FreeS/WAN) brings IPsec to Linux, and Netlock pulls the Mac, Solaris, HP-UX, and IBM-AIX onto the VPN. Watch the Virtual Private Network Consortium (VPNC) for information about other multi-platform developments.
That's it for part 2. Keep the fixes simple and you'll probably keep the tunnel traffic moving faster than a speeding bulletor at least moving again sooner.