F. SNMP MIB Objects
3160-A2-GB24-10 March 2001 F-11
IP Group – “ipRouteTable” Object (ip 21)
The routing table used by the DSU/CSU is supported as a read/write table. Entr ies
in this table may be added, deleted, or changed. You should exercise great caution
when adding or modifying routes in the ipRoutingTable. In general, it should not be
necessary to add or modify routes in the DSU/CSU. In those cases where it is
deemed necessary, the routes should only be added to the connected device
(i.e., the device closest to the destination). Internal routing mechanisms will
propagate the route to the other devices.
An existing route may be effectively deleted by setting the ipRouteType object to
“invalid”for the entry to be deleted. An existing route may be modified by changing
fields in the desired entry (indexed by ipRouteDest) of the routing table. A new
route may be added by specifying values for a table entry for which the index
(“ipRouteDest”) does not already exist.
To add a route using an SNMP set, you must specify a group of minimal objects.
These variable bindings must be contained in a single Protocol Data Unit (PDU).
The objects are described in more detail in the following sections. The minimal set
consists of:
ipRouteDest
ipRouteIfIndex
The following objects are defaulted if not specified in the set PDU used to add a
route.
ipRouteMetric1 – Defaulted to 1 hop.
ipRouteMetric2 – Defaulted to current slot for carrier devices and –1 for
standalone devices.
ipRouteType – Defaulted to indirect.
ipRouteMask – Defaulted as specified in the MIB description.
The following objects are unused in the DSU/CSU and setting them will have no
effect on the operation of the IP implementation.
ipRouteMetric3, ipRouteMetric4, ipRouteMetric5 – Defaulted to –1 as
specified in the MIB.
ipRouteNextHop – Defaulted to 0.0.0.0.
The following read-only objects must not be specified in the set PDU used to add a
route.
ipRouteProto – Set to netmgmt(3) by software.
ipRouteAge – Defaulted to 999.
ipRouteInfo – Set to OBJECT IDENTIFIER {0, 0} since it is unused.