guys we have 4 sites A,B,C,D all are connected via dark fiber (ethernet).
now A is also connected with ---D
ISIS is the routing protocol
all routers have loopbacks as well
now all physical interfaces should be in area 43.0010 and shd run level 1
now site BC loopback interfaces should be in same area as above and should run level 1 as well.
site A and D loopback should be in different area 47.2010 and should run level 2
the problem is its poretty straight forward but i am nnot allowed to use seperate instance of ISIS i m going nuts is it possible if yes how....thanks for your help guys.....