5.3. The Address Translation Group Implementation of the Address Translation group is mandatory for all systems. Note however that this group is deprecated by MIB-II. That is, it is being included solely for compatibility with MIB-I nodes, and will most likely be excluded from MIB-III nodes. From MIB-II and onwards, each network protocol group contains its own address translation tables. The Address Translation group contains one table which is the union across all interfaces of the translation tables for converting a NetworkAddress (e.g., an IP address) into a subnetwork-specific address. For lack of a better term, this document refers to such a subnetwork-specific address as a "physical" address. Examples of such translation tables are: for broadcast media where ARP is in use, the translation table is equivalent to the ARP cache; or, on an X.25 network where non-algorithmic translation to X.121 addresses is required, the translation table contains the NetworkAddress to X.121 address equivalences. OBJECT: ------- atTable { at 1 } Syntax: SEQUENCE OF AtEntry Definition: The Address Translation tables contain the NetworkAddress to "physical" address equivalences. Some interfaces do not use translation tables for determining address equivalences (e.g., DDN-X.25 has an algorithmic method); if all interfaces are of this type, then the Address Translation table is empty, i.e., has zero entries. Access: read-write.
Status: deprecated. OBJECT: ------- atEntry { atTable 1 } Syntax: AtEntry ::= SEQUENCE { atIfIndex INTEGER, atPhysAddress OCTET STRING, atNetAddress NetworkAddress } Definition: Each entry contains one NetworkAddress to "physical" address equivalence. Access: read-write. Status: deprecated. We now consider the individual components of each Address Translation table entry: OBJECT: ------- atIfIndex { atEntry 1 } Syntax: INTEGER Definition: The interface on which this entry's equivalence is effective. The interface identified by a particular value of this index is the same interface as identified by the same value of ifIndex. Access: read-write.
Status: deprecated. OBJECT: ------- atPhysAddress { atEntry 2 } Syntax: OCTET STRING Definition: The media-dependent "physical" address. Setting this object to a null string (one of zero length) has the effect of invaliding the corresponding entry in the atTable object. That is, it effectively disassociates the interface identified with said entry from the mapping identified with said entry. It is an implementation-specific matter as to whether the agent removes an invalidated entry from the table. Accordingly, management stations must be prepared to receive tabular information from agents that corresponds to entries not currently in use. Proper interpretation of such entries requires examination of the relevant atPhysAddress object. Access: read-write. Status: deprecated. OBJECT: ------- atNetAddress { atEntry 3 } Syntax: NetworkAddress Definition: The NetworkAddress (e.g., the IP address) corresponding to the media-dependent "physical" address. Access: read-write.
Status: deprecated. 5.4. The IP Group Implementation of the IP group is mandatory for all systems. OBJECT: ------- ipForwarding { ip 1 } Syntax: INTEGER { forwarding(1), -- i.e., acting as a gateway not-forwarding(2) -- i.e., NOT acting as a gateway } Definition: The indication of whether this entity is acting as an IP gateway in respect to the forwarding of datagrams received by, but not addressed to, this entity. IP gateways forward datagrams. IP hosts do not (except those source-routed via the host). Access: read-write. Status: mandatory. OBJECT: ------- ipDefaultTTL { ip 2 } Syntax: INTEGER Definition: The default value inserted into the Time-To-Live field of the IP header of datagrams originated at this entity, whenever a TTL value is not supplied by the transport layer protocol. Access: read-write.
Status: mandatory. OBJECT: ------- ipInReceives { ip 3 } Syntax: Counter Definition: The total number of input datagrams received from interfaces, including those received in error. Access: read-only. Status: mandatory. OBJECT: ------- ipInHdrErrors { ip 4 } Syntax: Counter Definition: The number of input datagrams discarded due to errors in their IP headers, including bad checksums, version number mismatch, other format errors, time-to-live exceeded, errors discovered in processing their IP options, etc. Access: read-only. Status: mandatory. OBJECT: ------- ipInAddrErrors { ip 5 } Syntax: Counter
Definition: The number of input datagrams discarded because the IP address in their IP header's destination field was not a valid address to be received at this entity. This count includes invalid addresses (e.g., 0.0.0.0) and addresses of unsupported Classes (e.g., Class E). For entities which are not IP Gateways and therefore do not forward datagrams, this counter includes datagrams discarded because the destination address was not a local address. Access: read-only. Status: mandatory. OBJECT: ------- ipForwDatagrams { ip 6 } Syntax: Counter Definition: The number of input datagrams for which this entity was not their final IP destination, as a result of which an attempt was made to find a route to forward them to that final destination. In entities which do not act as IP Gateways, this counter will include only those packets which were Source-Routed via this entity, and the Source-Route option processing was successful. Access: read-only. Status: mandatory. OBJECT: ------- ipInUnknownProtos { ip 7 } Syntax: Counter
Definition: The number of locally-addressed datagrams received successfully but discarded because of an unknown or unsupported protocol. Access: read-only. Status: mandatory. OBJECT: ------- ipInDiscards { ip 8 } Syntax: Counter Definition: The number of input IP datagrams for which no problems were encountered to prevent their continued processing, but which were discarded (e.g., for lack of buffer space). Note that this counter does not include any datagrams discarded while awaiting re-assembly. Access: read-only. Status: mandatory. OBJECT: ------- ipInDelivers { ip 9 } Syntax: Counter Definition: The total number of input datagrams successfully delivered to IP user-protocols (including ICMP). Access: read-only.
Status: mandatory. OBJECT: ------- ipOutRequests { ip 10 } Syntax: Counter Definition: The total number of IP datagrams which local IP user- protocols (including ICMP) supplied to IP in requests for transmission. Note that this counter does not include any datagrams counted in ipForwDatagrams. Access: read-only. Status: mandatory. OBJECT: ipOutDiscards { ip 11 } Syntax: Counter Definition: The number of output IP datagrams for which no problem was encountered to prevent their transmission to their destination, but which were discarded (e.g., for lack of buffer space). Note that this counter would include datagrams counted in ipForwDatagrams if any such packets met this (discretionary) discard criterion. Access: read-only. Status: mandatory. OBJECT: ------- ipOutNoRoutes { ip 12 }
Syntax: Counter Definition: The number of IP datagrams discarded because no route could be found to transmit them to their destination. Note that this counter includes any packets counted in ipForwDatagrams which meet this "no-route" criterion. Note that this includes any datagarms which a host cannot route because all of its default gateways are down. Access: read-only. Status: mandatory. OBJECT: ------- ipReasmTimeout { ip 13 } Syntax: INTEGER Definition: The maximum number of seconds which received fragments are held while they are awaiting reassembly at this entity. Access: read-only. Status: mandatory. OBJECT: ------- ipReasmReqds { ip 14 } Syntax: Counter Definition: The number of IP fragments received which needed to be reassembled at this entity.
Access: read-only. Status: mandatory. OBJECT: ------- ipReasmOKs { ip 15 } Syntax: Counter Definition: The number of IP datagrams successfully re-assembled. Access: read-only. Status: mandatory. OBJECT: ------- ipReasmFails { ip 16 } Syntax: Counter Definition: The number of failures detected by the IP re-assembly algorithm (for whatever reason: timed out, errors, etc). Note that this is not necessarily a count of discarded IP fragments since some algorithms (notably the algorithm in RFC 815) can lose track of the number of fragments by combining them as they are received. Access: read-only. Status: mandatory.
OBJECT: ------- ipFragOKs { ip 17 } Syntax: Counter Definition: The number of IP datagrams that have been successfully fragmented at this entity. Access: read-only. Status: mandatory. OBJECT: ------- ipFragFails { ip 18 } Syntax: Counter Definition: The number of IP datagrams that have been discarded because they needed to be fragmented at this entity but could not be, e.g., because their "Don't Fragment" flag was set. Access: read-only. Status: mandatory. OBJECT: ------- ipFragCreates { ip 19 } Syntax: Counter Definition: The number of IP datagram fragments that have been generated as a result of fragmentation at this entity.
Access: read-only. Status: mandatory. 5.4.1. The IP Address table The Ip Address table contains this entity's IP addressing information. OBJECT: ------- ipAddrTable { ip 20 } Syntax: SEQUENCE OF IpAddrEntry Definition: The table of addressing information relevant to this entity's IP addresses. Access: read-only. Status: mandatory. OBJECT: ------- ipAddrEntry { ipAddrTable 1 } Syntax: IpAddrEntry ::= SEQUENCE { ipAdEntAddr IpAddress, ipAdEntIfIndex INTEGER, ipAdEntNetMask IpAddress, ipAdEntBcastAddr INTEGER, ipAdEntReasmMaxSize INTEGER (0..65535) }
Definition: The addressing information for one of this entity's IP addresses. Access: read-only. Status: mandatory. OBJECT: ------- ipAdEntAddr { ipAddrEntry 1 } Syntax: IpAddress Definition: The IP address to which this entry's addressing information pertains. Access: read-only. Status: mandatory. OBJECT: ------- ipAdEntIfIndex { ipAddrEntry 2 } Syntax: INTEGER Definition: The index value which uniquely identifies the interface to which this entry is applicable. The interface identified by a particular value of this index is the same interface as identified by the same value of ifIndex. Access: read-only. Status: mandatory.
OBJECT: ------- ipAdEntNetMask { ipAddrEntry 3 } Syntax: IpAddress Definition: The subnet mask associated with the IP address of this entry. The value of the mask is an IP address with all the network bits set to 1 and all the hosts bits set to 0. Access: read-only. Status: mandatory. OBJECT: ------- ipAdEntBcastAddr { ipAddrEntry 4 } Syntax: INTEGER Definition: The value of the least-significant bit in the IP broadcast address used for sending datagrams on the (logical) interface associated with the IP address of this entry. For example, when the Internet standard all-ones broadcast address is used, the value will be 1. This value applies to both the subnet and network broadcasts addresses used by the entity on this (logical) interface. Access: read-only. Status: mandatory. OBJECT: ------- ipAdEntReasmMaxSize { ipAddrEntry 5 }
Syntax: INTEGER (0..65535) Definition: The size of the largest IP datagram which this entity can re-assemble from incoming IP fragmented datagrams received on this interface. Access: read-only. Status: mandatory. 5.4.2. The IP Routing table The IP Routing table contains an entry for each route presently known to this entity. OBJECT: ------- ipRoutingTable { ip 21 } Syntax: SEQUENCE OF IpRouteEntry Definition: This entity's IP Routing table. Access: read-write. Status: mandatory. OBJECT: ------- ipRouteEntry { ipRoutingTable 1 } Syntax: IpRouteEntry ::= SEQUENCE { ipRouteDest IpAddress, ipRouteIfIndex INTEGER, ipRouteMetric1
INTEGER, ipRouteMetric2 INTEGER, ipRouteMetric3 INTEGER, ipRouteMetric4 INTEGER, ipRouteNextHop IpAddress, ipRouteType INTEGER, ipRouteProto INTEGER, ipRouteAge INTEGER, ipRouteMask IpAddress } Definition: A route to a particular destination. Access: read-write. Status: mandatory. We now consider the individual components of each route in the IP Routing table: OBJECT: ------- ipRouteDest { ipRouteEntry 1 } Syntax: IpAddress Definition: The destination IP address of this route. An entry with a value of 0.0.0.0 is considered a default route. Multiple routes to a single destination can appear in the table, but access to such multiple entries is dependent on the table-access mechanisms defined by the network management protocol in use.
Access: read-write. Status: mandatory. OBJECT: ------- ipRouteIfIndex { ipRouteEntry 2 } Syntax: INTEGER Definition: The index value which uniquely identifies the local interface through which the next hop of this route should be reached. The interface identified by a particular value of this index is the same interface as identified by the same value of ifIndex. Access: read-write. Status: mandatory. OBJECT: ------- ipRouteMetric1 { ipRouteEntry 3 } Syntax: INTEGER Definition: The primary routing metric for this route. The semantics of this metric are determined by the routing-protocol specified in the route's ipRouteProto value. If this metric is not used, its value should be set to -1. Access: read-write. Status: mandatory.
OBJECT: ------- ipRouteMetric2 { ipRouteEntry 4 } Syntax: INTEGER Definition: An alternate routing metric for this route. The semantics of this metric are determined by the routing- protocol specified in the route's ipRouteProto value. If this metric is not used, its value should be set to -1. Access: read-write. Status: mandatory. OBJECT: ------- ipRouteMetric3 { ipRouteEntry 5 } Syntax: INTEGER Definition: An alternate routing metric for this route. The semantics of this metric are determined by the routing- protocol specified in the route's ipRouteProto value. If this metric is not used, its value should be set to -1. Access: read-write. Status: mandatory. OBJECT: ------- ipRouteMetric4 { ipRouteEntry 6 } Syntax: INTEGER
Definition: An alternate routing metric for this route. The semantics of this metric are determined by the routing- protocol specified in the route's ipRouteProto value. If this metric is not used, its value should be set to -1. Access: read-write. Status: mandatory. OBJECT: ------- ipRouteNextHop { ipRouteEntry 7 } Syntax: IpAddress Definition: The IP address of the next hop of this route. (In the case of a route bound to an interface which is realized via a broadcast media, the value of this field is the agent's IP address on that interface.) Access: read-write. Status: mandatory. OBJECT: ------- ipRouteType { ipRouteEntry 8 } Syntax: INTEGER { other(1), -- none of the following invalid(2), -- an invalidated route -- route to directly direct(3), -- connected (sub-)network -- route to a non-local remote(4) -- host/network/sub-network
} Definition: The type of route. Setting this object to the value invalid(2) has the effect of invalidating the corresponding entry in the ipRoutingTable object. That is, it effectively disassociates the destination identified with said entry from the route identified with said entry. It is an implementation-specific matter as to whether the agent removes an invalidated entry from the table. Accordingly, management stations must be prepared to receive tabular information from agents that corresponds to entries not currently in use. Proper interpretation of such entries requires examination of the relevant ipRouteType object. Access: read-write. Status: mandatory. OBJECT: ------- ipRouteProto { ipRouteEntry 9 } Syntax: INTEGER { other(1), -- none of the following -- non-protocol information, -- e.g., manually configured local(2), -- entries -- set via a network management netmgmt(3), -- protocol -- obtained via ICMP, icmp(4), -- e.g., Redirect -- the remaining values are -- all gateway routing protocols egp(5), ggp(6), hello(7), rip(8), is-is(9),
es-is(10), ciscoIgrp(11), bbnSpfIgp(12), ospf(13), bgp(14) } Definition: The routing mechanism via which this route was learned. Inclusion of values for gateway routing protocols is not intended to imply that hosts should support those protocols. Access: read-only. Status: mandatory. OBJECT: ------- ipRouteAge { ipRouteEntry 10 } Syntax: INTEGER Definition: The number of seconds since this route was last updated or otherwise determined to be correct. Note that no semantics of "too old" can be implied except through knowledge of the routing protocol by which the route was learned. Access: read-write. Status: mandatory. OBJECT: ------- ipRouteMask { ipRouteEntry 11 } Syntax: IpAddress
Definition: Indicate the mask to be logical-ANDed with the destination address before being compared to the value in the ipRouteDest field. For those systems that do not support arbitrary subnet masks, an agent constructs the value of the ipRouteMask by determining whether the value of the correspondent ipRouteDest field belong to a class-A, B, or C network, and then using one of: mask network 255.0.0.0 class-A 255.255.0.0 class-B 255.255.255.0 class-C If the value of the ipRouteDest is 0.0.0.0 (a default route), then the mask value is also 0.0.0.0. It should be noted that all IP routing subsystems implicitly use this mechanism. Access: read-write. Status: mandatory. 5.4.3. The IP Address Translation table The Address Translation tables contain the IpAddress to "physical" address equivalences. Some interfaces do not use translation tables for determining address equivalences (e.g., DDN-X.25 has an algorithmic method); if all interfaces are of this type, then the Address Translation table is empty, i.e., has zero entries. OBJECT: ------- ipNetToMediaTable { ip 22 } Syntax: SEQUENCE OF IpNetToMediaEntry Definition: The IP Address Translation table used for mapping from IP addresses to physical addresses. Access: read-write.
Status: mandatory. OBJECT: ------- IpNetToMediaEntry { ipNetToMediaTable 1 } Syntax: IpNetToMediaEntry ::= SEQUENCE { ipNetToMediaIfIndex INTEGER, ipNetToMediaPhysAddress OCTET STRING, ipNetToMediaNetAddress IpAddress, ipNetToMediaType INTEGER } Definition: Each entry contains one IpAddress to "physical" address equivalence. Access: read-write. Status: mandatory. We now consider the individual components of each IP Address Translation table entry: OBJECT: ------- ipNetToMediaIfIndex { ipNetToMediaEntry 1 } Syntax: INTEGER Definition: The interface on which this entry's equivalence is effective. The interface identified by a particular value of this index is the same interface as identified by the same value of ifIndex.
Access: read-write. Status: mandatory. OBJECT: ------- ipNetToMediaPhysAddress { ipNetToMediaEntry 2 } Syntax: OCTET STRING Definition: The media-dependent "physical" address. Access: read-write. Status: mandatory. OBJECT: ------- ipNetToMediaNetAddress { ipNetToMediaEntry 3 } Syntax: IpAddress Definition: The IpAddress corresponding to the media-dependent "physical" address. Access: read-write. Status: mandatory. OBJECT: ------- ipNetToMediaType { ipNetToMediaEntry 4 } Syntax: INTEGER {
other(1), -- none of the following invalid(2), -- an invalidated mapping dynamic(3), static(4) } Definition: The type of mapping. Setting this object to the value invalid(2) has the effect of invalidating the corresponding entry in the ipNetToMediaTable. That is, it effectively disassociates the interface identified with said entry from the mapping identified with said entry. It is an implementation-specific matter as to whether the agent removes an invalidated entry from the table. Accordingly, management stations must be prepared to receive tabular information from agents that corresponds to entries not currently in use. Proper interpretation of such entries requires examination of the relevant ipNetToMediaType object. Access: read-write. Status: mandatory. 5.5. The ICMP Group Implementation of the ICMP group is mandatory for all systems. The ICMP group contains the ICMP input and output statistics. OBJECT: ------- icmpInMsgs { icmp 1 } Syntax: Counter Definition: The total number of ICMP messages which the entity received. Note that this counter includes all those counted by icmpInErrors.
Access: read-only. Status: mandatory. OBJECT: ------- icmpInErrors { icmp 2 } Syntax: Counter Definition: The number of ICMP messages which the entity received but determined as having ICMP-specific errors (bad ICMP checksums, bad length, etc.). Access: read-only. Status: mandatory. OBJECT: ------- icmpInDestUnreachs { icmp 3 } Syntax: Counter Definition: The number of ICMP Destination Unreachable messages received. Access: read-only. Status: mandatory. OBJECT: ------- icmpInTimeExcds { icmp 4 }
Syntax: Counter Definition: The number of ICMP Time Exceeded messages received. Access: read-only. Status: mandatory. OBJECT: ------- icmpInParmProbs { icmp 5 } Syntax: Counter Definition: The number of ICMP Parameter Problem messages received. Access: read-only. Status: mandatory. OBJECT: ------- icmpInSrcQuenchs { icmp 6 } Syntax: Counter Definition: The number of ICMP Source Quench messages received. Access: read-only. Status: mandatory.
OBJECT: ------- icmpInRedirects { icmp 7 } Syntax: Counter Definition: The number of ICMP Redirect messages received. Access: read-only. Status: mandatory. OBJECT: ------- icmpInEchos { icmp 8 } Syntax: Counter Definition: The number of ICMP Echo (request) messages received. Access: read-only. Status: mandatory. OBJECT: ------- icmpInEchoReps { icmp 9 } Syntax: Counter Definition: The number of ICMP Echo Reply messages received. Access: read-only.
Status: mandatory. OBJECT: ------- icmpInTimestamps { icmp 10 } Syntax: Counter Definition: The number of ICMP Timestamp (request) messages received. Access: read-only. Status: mandatory. OBJECT: ------- icmpInTimestampReps { icmp 11 } Syntax: Counter Definition: The number of ICMP Timestamp Reply messages received. Access: read-only. Status: mandatory. OBJECT: ------- icmpInAddrMasks { icmp 12 } Syntax: Counter Definition: The number of ICMP Address Mask Request messages received.
Access: read-only. Status: mandatory. OBJECT: ------- icmpInAddrMaskReps { icmp 13 } Syntax: Counter Definition: The number of ICMP Address Mask Reply messages received. Access: read-only. Status: mandatory. OBJECT: ------- icmpOutMsgs { icmp 14 } Syntax: Counter Definition: The total number of ICMP messages which this entity attempted to send. Note that this counter includes all those counted by icmpOutErrors. Access: read-only. Status: mandatory. OBJECT: ------- icmpOutErrors { icmp 15 }
Syntax: Counter Definition: The number of ICMP messages which this entity did not send due to problems discovered within ICMP such as a lack of buffers. This value should not include errors discovered outside the ICMP layer such as the inability of IP to route the resultant datagram. In some implementations there may be no types of error which contribute to this counter's value. Access: read-only. Status: mandatory. OBJECT: ------- icmpOutDestUnreachs { icmp 16 } Syntax: Counter Definition: The number of ICMP Destination Unreachable messages sent. Access: read-only. Status: mandatory. OBJECT: ------- icmpOutTimeExcds { icmp 17 } Syntax: Counter Definition: The number of ICMP Time Exceeded messages sent. Access: read-only.
Status: mandatory. OBJECT: ------- icmpOutParmProbs { icmp 18 } Syntax: Counter Definition: The number of ICMP Parameter Problem messages sent. Access: read-only. Status: mandatory. OBJECT: ------- icmpOutSrcQuenchs { icmp 19 } Syntax: Counter Definition: The number of ICMP Source Quench messages sent. Access: read-only. Status: mandatory. OBJECT: ------- icmpOutRedirects { icmp 20 } Syntax: Counter Definition: The number of ICMP Redirect messages sent. For a host, this object will always be zero, since hosts do not send
redirects. Access: read-only. Status: mandatory. OBJECT: ------- icmpOutEchos { icmp 21 } Syntax: Counter Definition: The number of ICMP Echo (request) messages sent. Access: read-only. Status: mandatory. OBJECT: ------- icmpOutEchoReps { icmp 22 } Syntax: Counter Definition: The number of ICMP Echo Reply messages sent. Access: read-only. Status: mandatory. OBJECT: ------- icmpOutTimestamps { icmp 23 }
Syntax: Counter Definition: The number of ICMP Timestamp (request) messages sent. Access: read-only. Status: mandatory. OBJECT: ------- icmpOutTimestampReps { icmp 24 } Syntax: Counter Definition: The number of ICMP Timestamp Reply messages sent. Access: read-only. Status: mandatory. OBJECT: ------- icmpOutAddrMasks { icmp 25 } Syntax: Counter Definition: The number of ICMP Address Mask Request messages sent. Access: read-only. Status: mandatory.
OBJECT: ------- icmpOutAddrMaskReps { icmp 26 } Syntax: Counter Definition: The number of ICMP Address Mask Reply messages sent. Access: read-only. Status: mandatory.