IPSec VPN SPA can use multiple Fast Ethernet or Gigabit Ethernet ports on other Catalyst 6500 series switch modules to connect to the Internet through WAN routers. Packets that are received from the WAN routers pass through the IPSec VPN SPA for IPSec processing.
On the LAN side, traffic between the LAN ports can be routed or bridged on multiple Fast Ethernet or Gigabit Ethernet ports. Because the LAN traffic is not encrypted or decrypted, it does not pass through the IPSec VPN SPA. The IPSec VPN SPA does not maintain routing information, route, or change the MAC header of a packet (except for the VLAN ID from one VLAN to another).