IP Monitoring

IP monitoring is an important task in network management. The ip group  OID is 1.3.6.1.2.1.4(mib.ip).

This group defines 20 variables and three tables. All variables are ordered in the next table by its OID.

OID      Name                   Datatype  Writable Description

1        ipForwading           INTEGER        yes        Indicates if this device is working as a gateway

2        ipDefaultTTL           INTEGER        yes        The default Time-To-Live value if the transport protocol doesn't provide one

3        ipInReceives           Counter        no        Total number of ip datagrams received

4        ipInHdrErrors           Counter        no        Number of discarded datagrams because a header error was found

5        ipInAddrErrors           Counter        no        Total number of discarded datagrams because an error in the destination address was found

6        ipForwDatagrams   Counter        no        Number of forwaded ip datagrams

7        ipInUnknownProtos Counter        no        Number of received ip datagrams discarded due to an invalid protocol field

8        ipInDiscards           Counter        no        Total number of input IP datagrams without processing errors, but were discarded(e.g., lack of

                                                                      buffer space)

9        ipInDelivers           Counter        no        Number of received IP datagrams correctly delivered to the user-protocol.

10        ipOutRequests           Counter        no        Total number of sent IP datagrams. This counter don't include those counted in ipForwDatagrams

11        ipOutDiscards           Counter        no        Number of output IP datagrams discarded due to lack of buffer space

12        ipOutNoRoute           Counter        no        Total number of output IP datagrams discarded due no route could be found to transmit them to

                                                                      their destination

13        ipReasmTimeout    INTEGER        no        Number of seconds that received fragments are held awaiting reassembly

14        ipReasmReqds           Counter        no        Total number of received IP fragments that needed to be reassembled

15        ipReasmOKs           Counter        no        Total number of IP datagrams successfully reassembled

16        ipReasmFails           Counter        no        Total number of IP datagrams failed on the reassembly

17        ipFragOKs           Counter        no        Number of IP datagrams successfully fragmented

18        ipFragFails           Counter        no        Number of IP datagrams failed during the fragmentation

19        ipFragCreates           Counter        no        Number of IP fragments created as a result of fragmentation

23        ipRoutingDiscards  Counter        no        Number of discarded route entries even if no error was found

The first table is the ipAddrTable with the OID 20. It has one row for each IP address on the system.

All itens of this table is listed below:

OID      Name                           Datatype         Writable       Description

1        ipAdEntAddr                   IpAddress        no                IP address of the current table entry

2        ipAdEntIfIndex                   INTEGER        no                The interface number specified in ifIndex for this IP address

3        ipAdEntNetMask                   IpAddress        no                Associated subnet for this IP address

4        ipAdEntBcastAddr        INTEGER        no                Least-significant bit in the IP broadcast

5        ipAdEntReasmMaxSize        INTEGER        no                Maximum size of the IP datagram can be reassembled

The OID 21 of the ip group is the ipRouteTable. It is a table with 13 columns and a row for each destination address inserted.

OID      Name               Datatype   Writable    Description

1        ipRouteDest        IpAddress        yes        Destination IP address of this route.

2        ipRouteIfIndex        INTEGER        yes        Corresponding interface id(ifIndex)

3        ipRouteMetric1        INTEGER        yes        Primary route metric for this route. The value depends of ipRouteProto. If it

                                                                      is not in use the value will be -1

4        ipRouteMetric2        INTEGER        yes        Alternative routing metric for this route

5        ipRouteMetric3        INTEGER        yes        Alternative routing metric for this route

6        ipRouteMetric4        INTEGER        yes        Alternative routing metric for this route

7        ipRouteNextHop        IpAddress        yes        The next hop of this route

8        ipRouteType        INTEGER        yes        The type of the route that can be 1 for other, 2 for invalidated route, 3 for

                                                                      directly route and 4 for a non-local route

9        ipRouteProto        INTEGER        no        Routing protocol for this route. Possible values are 1 to other, 2 for local, 4 to

                                                                      ICMP redirect. The complete possible values is in The Internet Task Force -

                                                                      Management Information Base for Network Management of TCP/IP-based

                                                                      internets: MIB-II

10        ipRouteAge        INTEGER        yes        Time in seconds since the last update of this route

11        ipRouteMask        IpAddress        yes        A mask to be ANDed with the destination IP address before being compared

                                                                      to the value in ipRouteDest field

12        ipRouteMetric5        INTEGER        yes        Alternative routing metric for this route

13        ipRouteInfo        ObjectID        no        OID of the reference of this routing protocol

And the last table in the ip group is the ipNetToMediaTable with the OID 22. It is used to mapping the IP address to physical address.

OID      Name                                       Datatype        Writable          Description

1        ipNetToMediaIfIndex                   INTEGER        yes                  Wich interface this entry is effective

2        ipNetToMediaPhysAddress        PhysAddress        yes                  The physical address

3        ipNetToMediaNetAddress        IpAddress        yes                  Corresponding IP address to the physical address

4        ipNetToMediaType                   INTEGER        yes                  The type of mapping. It can be 1 for other, 2 for

                                                                                                         invalidated, 3 for dynamic and 4 for static