1) For the load-balancing you can use different approaches,
http://wiki.mikrotik.com/wiki/Routing
You can try PCC option.
2) Just add IP addresses to the local interface and do not use NAT rules.
3) Give us more information about PPP/Virtual cache.
In PCC Routing it says that:
/ ip address
add address=192.168.0.1/24 network=192.168.0.0 broadcast=192.168.0.255 interface=Local
add address=10.111.0.2/24 network=10.111.0.0 broadcast=10.111.0.255 interface=wlan1
add address=10.112.0.2/24 network=10.112.0.0 broadcast=10.112.0.255 interface=wlan2
/ ip firewall mangle
add chain=input in-interface=wlan1 action=mark-connection new-connection-mark=wlan1_conn
add chain=input in-interface=wlan2 action=mark-connection new-connection-mark=wlan2_conn
add chain=output connection-mark=wlan1_conn action=mark-routing new-routing-mark=to_wlan1
add chain=output connection-mark=wlan2_conn action=mark-routing new-routing-mark=to_wlan2
add chain=prerouting dst-address=10.111.0.0/24 action=accept in-interface=Local
add chain=prerouting dst-address=10.112.0.0/24 action=accept in-interface=Local
add chain=prerouting dst-address-type=!local in-interface=Local per-connection-classifier=both-addresses:2/0 \
action=mark-connection new-connection-mark=wlan1_conn passthrough=yes
add chain=prerouting dst-address-type=!local in-interface=Local per-connection-classifier=both-addresses:2/1 \
action=mark-connection new-connection-mark=wlan2_conn passthrough=yes
add chain=prerouting connection-mark=wlan1_conn in-interface=Local action=mark-routing new-routing-mark=to_wlan1
add chain=prerouting connection-mark=wlan2_conn in-interface=Local action=mark-routing new-routing-mark=to_wlan2
/ ip route
add dst-address=0.0.0.0/0 gateway=10.111.0.1 routing-mark=to_wlan1 check-gateway=ping
add dst-address=0.0.0.0/0 gateway=10.112.0.1 routing-mark=to_wlan2 check-gateway=ping
add dst-address=0.0.0.0/0 gateway=10.111.0.1 distance=1 check-gateway=ping
add dst-address=0.0.0.0/0 gateway=10.112.0.1 distance=2 check-gateway=ping
/ ip firewall nat
add chain=srcnat out-interface=wlan1 action=masquerade
add chain=srcnat out-interface=wlan2 action=masquerade
And the problem here is
/ ip firewall nat
add chain=srcnat out-interface=wlan1 action=masquerade
add chain=srcnat out-interface=wlan2 action=masquerade
if we use this 2 rules the clients have Virtual ip
NOT REAL IP
So this can't be use in our company.
for simple introduction we are Internet Service Providers
ALL of our recent topology is Cisco
we need to develope our topology with mikrotik and caching to improve our service
we are using now ( every Cisco 7200 for bandwidth and ip routing about
5 different REAL IP ranges)
Cisco 7200 --- Go to ---> Dslams --Go to--> ADSL Modems
and another
Cisco 7200 --- Go to ---> Dslams --Go to--> ADSL Modems
WE NEED TO IMPROVE IT TO BE
Cisco 7200 -->
MIKROTIK LoadBalancing/PPP --> Caching Server --> Dslams --> ADSL Modems
Cisco 7200 -->
OR TO BE
Cisco 7200 -->
MIKROTIK LoadBalancing/PPP -->
SWITCH <-- Dslams --> ADSL Modems
Caching Server -->
Cisco 7200 -->
This Adsl Modems (every customer) must has his real/public ip to use it over internet for rapidshare, 4shared ....
HOPE I explained the topology well else HOPE To Find Good Configuration For this