To use the IBM VPN (MTS — managed tunnel service) under linux, you’re required to run some binary code from AT&T that also requires a very tiny patch to the linux kernel to operate (the patch allows for heartbeat replies to come back to the attvpnctl daemon and not get dropped by the kernel).
If you try to use the VPN under a vanilla kernel, you are quickly booted for missing a heartbeat. Apparently it’s only the client-side daemon that cares about the heartbeat!
A fine hacker at work has replaced some of the ASM instructions in the binary to fool the (poorly-supported by ATT) vpn client, so that people can now use stock kernels! Wahoo!.
