Fix Shrew Soft VPN on Ubuntu 11.04

After upgrading my system to Ubuntu 11.04 I was no longer able to establish a VPN connection. Shrew Soft VPN would time out. It appears that the Reverse Path Filter was causing the issue.

Found the following solution:
Edit your network-security.conf to disable the Reverse Path Filter:

sudo vim /etc/sysctl.d/10-network-security.conf

Set the following items from 1 to 0:

net.ipv4.conf.default.rp_filter=0
net.ipv4.conf.all.rp_filter=0

Save and perform the following command.

sudo /sbin/sysctl -p