If you get the following message on your Cisco router when you connect a VPN client using PPTP *Mar 17 16:43:02.371: Vi5 PPP: Control packet rate limit 10 reached *Mar 17 16:43:02.371: Vi5 PPP: Entering block state for 30 seconds *Mar 17 16:43:02.371: Vi5 PPP: Packet throttled, Dropping packet Then it means you have an IOS version which greatly reduced the allowed rate of PPP control packets before it triggers a block....
So, like me, you want to have redundancy for your virtual machine network. For my lab setup, I use a refurbished Cisco router 3825 with two gigabit interfaces, two Procurve 2810-24G and a small server with 4 gigabit interfaces for the ESXi. You just have to: team the NICs on the ESXi (use src-mac + beacon probing), use port-channel on the Cisco router and src-mac too, configure the switches exactly the same way as if there wasn’t any redundancy, add a link between the two switches and configure it to transmit the VLANs you need, don’t forget to add STP on the switches and put a high priority (low number) on the link between the switches....