I have a doubt in ISIS.
While redistributing routes from other protocols, how the metric is decided?
OSPF has deccribed this in RFC 2328 Section 16.4 :
'4) Let X be the cost specified by the preferred routing
entry for the ASBR/forwarding address, and Y the cost
specified in the LSA. X is in terms of the link state
metric, and Y is a type 1 or 2 external metric.
(5) Look up the routing table entry for the destination N. If
no entry exists for N, install the AS external path to N,
with next hop equal to the list of next hops to the
forwarding address, and advertising router equal to ASBR.
If the external metric type is 1, then the path-type is set
to type 1 external and the cost is equal to X+Y. If the
external metric type is 2, the path-type is set to type 2
external, the link state component of the route's cost is X,
and the type 2 cost is Y.'
What is the behavior in ISIS?