How do I query from more than one server

Using SQL how would you make a query where your using the ip address as part of your table name in the select portion of the query?

Example

I have on IP xxx.xx.xx.xx DB1 table1 field1, field2

and

I have on IP zzz.zz.zz.zz DB2 table2 field1, field2

both servers are behind my fire wall and i can query them individually

I hope this makes sense.