here is my diagram. how can i configure both mikrotik and squid server?
WAN LINK
|
| Mikrotik Box | | Cache Linux Server |
| /
| / |
|---|
| Switch ( Cheap one ) |
| | |
Client1 Client2 Client3 etc.
can anybody help me about the above scenario 
Just setup a transparent proxy and point it to your external proxy address, or send it to the MT proxy, and specify a parent proxy in there.
Better yet, just use the MT proxy built in!