You are welcome about comments about vlan needed or not. Sometimes we need to be careful about assumptions that we are making - and this was certainly one of those times. Your point was spot on that vlans were not needed and an IP address configured on the switch interface (with no switchport) was sufficient.
I do not think that DHCP would be particularly helpful in what you are planning to do. With DHCP addresses are assigned dynamically and there is some chance that, over time, a device might get a different IP address from what it had before. You need to be clear which devices go to D-Link for Internet and which devices go to ASA for Internet. I believe that manual configuration of devices would be safer than DHCP.
I am not sure what documentation you have been looking at for PBR. Let me give you some explanation and if you need more than what I give I will find some documentation that might be more simple and helpful.
Basically PBR uses a Policy that provides an over ride of normal IP routing logic in the routing table. PBR uses a route map to identify traffic and to specify how to forward that traffic that is different from what is found in the ip routing table. The route map uses an access list to identify the traffic that is to have special forwarding. The route map is assigned to the interface where the traffic enters the switch/router (a very common mistake is to assign the route map to the exit interface, which seems logical since we want to change how the packet gets out of the router).
This is a brief example of what you would need to do:
1) create 2 extended access lists (one will identify traffic going to D-Link and the other will identify traffic going to ASA). In this case the access list will match on source address. For this example I will assume that devices going to D-Link are using IP addresses 192.168.5.1 through 192.168.5.15 and devices going to ASA are using IP addresses 192.168.5.32 through 192.168.5.47. Of course your situation will probably be different.
access-list 101 permit ip 192.168.5.0 0.0.0.15 any
access-list 102 permit ip 192.168.5.32 0.0.0.15 any
2) configure a route map that will identify traffic and will specify how to forward it
ip policy ToInternet permit 10
match ip address 101
set ip next-hop 10.0.2.1
ip policy ToInternet permit 20
match ip address 102
set ip next-hop 192.168.1.1
3) assign the route map to the vlan interface where traffic enters the switch
interface vlan 12
ip policy route-map ToInternet
That should do it. If you want additional documentation let me know.
HTH
Rick
