Hello,

on your 1811 you have to use NAT.

You define two different NAT address pools one for public block 1 (70.x.x.x) and one for public block 2 (69.x.x.x).

You declare the interface(s) to the outer world as NAT outside using ip nat outside.

You define two standard IP ACLs that you use in combination with the addres pools to specify that 192.168.0./24 has to be translated into block1 and 192.168.2.0/24 into block2.

see the following link:

http://www.cisco.com/en/US/docs/ios/ipaddr/configuration/guide/iadnat_addr_consv_ps6350_TSD_Products_Configuration_Guide_Chapter.html#wp1047771

Example:

access-list 11 permit 192.168.0.0 0.0.0.255

access-list 12 permit 192.168.2.0 0.0.0.255

ip nat pool block1 70.x.x.2 70.x.x.254 netmask 255.255.255.0

ip nat pool block2 69.x.x.2 69.x.x.254 netmask 255.255.255.0

! here the nat

ip nat inside source list 11 pool block1

ip nat inside source list 12 pool block2

int fas0/1

ip nat outside

int fas0/0.50

desc regular wired users here

ip nat inside

intfas0/0.100

desc wireless users here

ip nat inside

for the requirement you just need to use and extended outbound acl to deny traffic originated by 192.168.2.0/24

access-list 125 deny ip 192.168.2.0 0.0.0.255 any

access-list 125 permit ip any any

int fas0/0.50

desc regular wired users here

ip access-group 125 out

hope to help

Giuseppe