Can any one explain me about parameter permanent
ip route X.Y.Z.0 255.255.255.0 A.B.C.1 permanent
If you have a static route with AD equal 1 and with permanent specified, then it will always be in the routing table (even if the next hop is not reachable) and the second route with higher distance will never be put into the routing table or used.
This is one aspect that should be evaluated in making the decision whether to specify permanent. Someone made the decision to use permanent and it prevents using floating static routes to get around a failure.