Subject: RFC vs. MIB internal metric contradiction

From: Magnus Andersson <[email-masked]>
Date: Tue, 30 Apr 2002 08:47:30 -0400

After reading both RFC2328 and J.Moy(OSPF, Anatonomy of an Internet Routing
protocol) I understand that 0 is not a valid number for the metric field in
the router-LSA. However in the OSPFv2 MIB it seems that 0 is a valid value.
Are there other situations where we allow a metric of 0, or why does the
MIB say that we can use 0??

--  Note the OSPF Metric is defined as an unsigned value in the range
Metric ::= TEXTUAL-CONVENTION        STATUS       current        DESCRIPTION
           "The OSPF Internal Metric."
        SYNTAX       Integer32 (0..'FFFF'h)

RFC2328:
Interface output cost(s)
        The cost of sending a data packet on the interface, expressed in
        the link state metric.  This is advertised as the link cost for
        this interface in the router-LSA. The cost of an interface must
        be greater than zero.Interface output cost(s)
        The cost of sending a data packet on the interface, expressed in
        the link state metric.  This is advertised as the link cost for
        this interface in the router-LSA. The cost of an interface must
        be greater than zero.

OSPF, Anatonomy of an Internet Routing protocol:
        Each link also contains a Metric field. This field ranging from 1
        to 65535, indicates the relative cost of sending packets over the
        link.