IPv6-MIB

1.3.6.1.2.1.55.1.1

ipv6Forwarding

INTEGER{forwarding(1),notForwarding(2)}

Read-write

The indication of whether this entity is acting as an IPv6 router in respect to the forwarding of datagrams received by, but not addressed to, this entity. IPv6 routers forward datagrams.

IPv6 hosts do not (except those source-routed via the host).

Note that for some managed nodes, this object may take on only a subset of the values possible.

Accordingly, it is appropriate for an agent to return a 'wrongValue' response if a management station attempts to change this object to an inappropriate value.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.2

ipv6DefaultHopLimit

INTEGER (0..255)

Read-write

The default value inserted into the Hop Limit field of the IPv6 header of datagrams originated at this entity, whenever a Hop Limit value is not supplied by the transport layer protocol.

By default, its value is 64.

Currently, only the values from 1 through 255 are supported.

1.3.6.1.2.1.55.1.3

ipv6Interfaces

Unsigned32

Read-only

The number of IPv6 interfaces (regardless of their current state) present on this system.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.4

ipv6IfTableLastChange

TimeTicks

Read-only

The value of sysUpTime at the time of the last insertion or removal of an entry in the ipv6IfTable. If the number of entries has been unchanged since the last re-initialization of the local network management subsystem, then this object contains a zero value.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.9

ipv6RouteNumber

INTEGER (0..4294967295)

Read-only

The number of current ipv6RouteTable entries.

This is primarily to avoid having to read the table in order to determine this number.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.10

ipv6DiscardedRoutes

INTEGER (0..4294967295)

Read-only

The number of routing entries which were chosen to be discarded even though they are valid.

One possible reason for discarding such an entry could be to free-up buffer space for other routing entries.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.5.1.1

ipv6IfIndex

Integer32 (1..2147483647)

Not-accessible

The value of the object is a unique non-zero value, which is used to identify a specified IPv6 interface.

The value ranges from 1 to 2147483647.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.5.1.2

ipv6IfDescr

OCTET STRING (SIZE (1..64))

Read-write

The field contains the text character string of port information with empty string supported. This string may be set by the network management system.

The value ranges from 1 to 242.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.5.1.3

ipv6IfLowerLayer

OBJECT IDENTIFIER

Read-only

This object identifies the protocol layer over which this network interface operates.

If this network interface operates over the data-link layer, then the value of this object refers to an instance of ifIndex [6].

If this network interface operates over an IPv4 interface, the value of this object refers to an instance of ipAdEntAddr [3].

If this network interface operates over another IPv6 interface, the value of this object refers to an instance of ipv6IfIndex.

If this network interface is not currently operating over an active protocol layer, then the value of this object should be set to the OBJECT ID { 0 0 }.

Currently, only the value OBJECT ID { 0 0 } is supported.

1.3.6.1.2.1.55.1.5.1.4

ipv6IfEffectiveMtu

INTEGER (0..4294967295)

Read-only

The value of this object identifies the largest size of the IPv6 packets that can be sent and received on the interface, in octets.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.5.1.5

ipv6IfReasmMaxSize

Unsigned32(0..65535)

Read-only

The size of the largest IPv6 datagram which this entity can re-assemble from incoming IPv6 fragmented datagrams received on this interface.

Currently, only the maximum size 65535 is supported.

1.3.6.1.2.1.55.1.5.1.6

ipv6IfIdentifier

OCTET STRING (SIZE (0..8))

Read-write

The Interface Identifier for this interface that is (at least) unique on the link this interface is attached to.

The Interface Identifier is combined with an address prefix to form an interface address.

By default, the Interface Identifier is automatically configured according to the rules of the link type this interface is attached to.

The value ranges from 0 to 8.

Currently, the maximum access is read-only.

1.3.6.1.2.1.55.1.5.1.7

ipv6IfIdentifierLength

INTEGER (0..64)

Read-write

The value of this object identifies the length of the interface identifier, in bits.

Currently, the maximum access is read-only; maximum length 64 is supported only.

1.3.6.1.2.1.55.1.5.1.8

ipv6IfPhysicalAddress

DisplayString (SIZE (0..255))

Read-only

The interface's physical address. For example, for an IPv6 interface attached to an 802.x link, this object normally contains a MAC address.

Note that in some cases this address may differ from the address of the interface's protocol sub-layer. The interface's media-specific MIB must define the bit and byte ordering and the format of the value of this object.

For interfaces which do not have such an address, this object should contain an octet string of zero length.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.5.1.9

ipv6IfAdminStatus

INTEGER{up(1),down(2)}

Read-write

The value of this object identifies the desired status of the interface.

When a managed system initializes, all IPv6 interfaces start with ipv6IfAdminStatus in the down(2) state.

As a result of either explicit management action or per configuration information retained by the managed system, ipv6IfAdminStatus is then changed to the up(1) state (or remains in the down(2) state).

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.5.1.10

ipv6IfOperStatus

INTEGER{up(1),down(2),noIfIdentifier(3),unknown(4),notPresent(5)}

Read-only

The value of this object identifies the current operating status of this interface.

The noIfIdentifier(3) state indicates that no valid Interface Identifier is assigned to the interface.

This state usually indicates that the link-local interface address failed Duplicate Address Detection.

If ipv6IfAdminStatus is down(2) then ipv6IfOperStatus should be down(2).

If ipv6IfAdminStatus is changed to up(1) then ipv6IfOperStatus should change to up(1) if the interface is ready to transmit and receive network traffic; it should remain in the down(2) or noIfIdentifier(3) state if and only if there is a fault that prevents it from going to the up(1) state; it should remain in the notPresent(5) state if the interface has missing (typically, lower layer) components.

Currently, only the statuses up(1) and down(2) are supported.

1.3.6.1.2.1.55.1.5.1.11

ipv6IfLastChange

TimeTicks

Read-only

The value of sysUpTime at the time the interface entered its current operational state.

If the current state was entered prior to the last re-initialization of the local network management subsystem, then this object contains a zero value.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.6.1.1

ipv6IfStatsInReceives

INTEGER (0..4294967295)

Read-only

The total number of input datagrams received by the interface, including those received in error.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.6.1.2

ipv6IfStatsInHdrErrors

INTEGER (0..4294967295)

Read-only

The number of input datagrams discarded due to errors in their IPv6 headers, such as version number mismatch, other format errors, hop count exceeded and errors discovered in processing their IPv6 options.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.6.1.3

ipv6IfStatsInTooBigErrors

INTEGER (0..4294967295)

Read-only

The number of input datagrams that could not be forwarded because their size exceeded the link MTU of outgoing interface. Statistics are actually collected on the outgoing interface.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.6.1.4

ipv6IfStatsInNoRoutes

INTEGER (0..4294967295)

Read-only

The number of input datagrams discarded because no route could be found to transmit them to their destination.

When the system forwards packets and fails to query a route, statistics are collected on the incoming interface; when the system sends packets and fails to query a router, statistics are collected on the outgoing interface.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.6.1.5

ipv6IfStatsInAddrErrors

INTEGER (0..4294967295)

Read-only

The number of input datagrams discarded because the IPv6 address in their IPv6 header's destination field was not a valid address to be received at this entity. This count includes invalid addresses (for example, ::) and unsupported addresses (for example, addresses with unallocated prefixes).

For entities which are not IPv6 routers and therefore do not forward datagrams, this counter includes datagrams discarded because the destination address was not a local address.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.6.1.6

ipv6IfStatsInUnknownProtos

INTEGER (0..4294967295)

Read-only

The number of locally-addressed datagrams received successfully but discarded because of an unknown or unsupported protocol.

This counter is incremented at the interface to which these datagrams were addressed which might not be necessarily the input interface for some of the datagrams.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.6.1.7

ipv6IfStatsInTruncatedPkts

INTEGER (0..4294967295)

Read-only

The number of input datagrams discarded because datagram frame didn't carry enough data.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.6.1.8

ipv6IfStatsInDiscards

INTEGER (0..4294967295)

Read-only

The number of input IPv6 datagrams for which no problems were encountered to prevent their continued processing, but which were discarded (for example, for lack of buffer space).

Note that this counter does not include any datagrams discarded while awaiting reassembly.

Statistics are disabled at present.

1.3.6.1.2.1.55.1.6.1.9

ipv6IfStatsInDelivers

INTEGER (0..4294967295)

Read-only

The total number of datagrams successfully delivered to IPv6 user-protocols (including ICMPv6).

This counter is incremented at the interface to which these datagrams were addressed which might not be necessarily the input interface for some of the datagrams.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.6.1.10

ipv6IfStatsOutForwDatagrams

INTEGER (0..4294967295)

Read-only

The number of output datagrams which this entity received and forwarded to their final destinations.

In entities which do not act as IPv6 routers, this counter will include only those packets which were Source-Routed via this entity, and the Source-Route processing was successful.

Note that for a successfully forwarded datagram the counter of the outgoing interface is incremented.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.6.1.11

ipv6IfStatsOutRequests

INTEGER (0..4294967295)

Read-only

The total number of IPv6 datagrams which local IPv6 user-protocols (including ICMPv6) supplied to IPv6 in requests for transmission.

Note that this counter does not include any datagrams counted in ipv6IfStatsOutForwDatagrams.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.6.1.12

ipv6IfStatsOutDiscards

INTEGER (0..4294967295)

Read-only

The number of output IPv6 datagrams for which no problem was encountered to prevent their transmission to their destination, but which were discarded (for example, for lack of buffer space).

Note that this counter would include datagrams counted in ipv6IfStatsOutForwDatagrams if any such packets met this (discretionary) discard criterion.

Statistics are disabled at present.

1.3.6.1.2.1.55.1.6.1.13

ipv6IfStatsOutFragOKs

INTEGER (0..4294967295)

Read-only

The number of IPv6 datagrams that have been successfully fragmented at this output interface.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.6.1.14

ipv6IfStatsOutFragFails

INTEGER (0..4294967295)

Read-only

The number of IPv6 datagrams that have been discarded because they needed to be fragmented at this output interface but could not be.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.6.1.15

ipv6IfStatsOutFragCreates

INTEGER (0..4294967295)

Read-only

The number of output datagram fragments that have been generated as a result of fragmentation at this output interface.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.6.1.16

ipv6IfStatsReasmReqds

INTEGER (0..4294967295)

Read-only

The number of IPv6 fragments received which needed to be reassembled at this interface.

Note that this counter is incremented at the interface to which these fragments were addressed which might not be necessarily the input interface for some of the fragments.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.6.1.17

ipv6IfStatsReasmOKs

INTEGER (0..4294967295)

Read-only

The number of IPv6 datagrams successfully reassembled.

Note that this counter is incremented at the interface to which these datagrams were addressed which might not be necessarily the input interface for some of the fragments.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.6.1.18

ipv6IfStatsReasmFails

INTEGER (0..4294967295)

Read-only

The number of failures detected by the IPv6 re-assembly algorithm (for whatever reason: such as timed out and errors).

Note that this is not necessarily a count of discarded IPv6 fragments since some algorithms (notably the algorithm in RFC 815) can lose information about the number of fragments by combining them as they are received.

This counter is incremented at the interface to which these fragments were addressed which might not be necessarily the input interface for some of the fragments.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.6.1.19

ipv6IfStatsInMcastPkts

INTEGER (0..4294967295)

Read-only

The value of this object identifies the number of multicast packets received by this interface.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.6.1.20

ipv6IfStatsOutMcastPkts

INTEGER (0..4294967295)

Read-only

The value of this object identifies the number of multicast packets sent by this interface.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.7.1.1

ipv6AddrPrefix

OCTET STRING (SIZE (0..16))

Not-accessible

The prefix associated with the interface.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.7.1.2

ipv6AddrPrefixLength

INTEGER (0..128)

Not-accessible

The value of this object identifies the length of the address prefix of the interface, in bits.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.7.1.3

ipv6AddrPrefixOnLinkFlag

INTEGER{true(1),false(2)}

Read-only

This object has the value 'true(1)', if this prefix can be used for on-link determination and the value 'false(2)' otherwise.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.7.1.4

ipv6AddrPrefixAutonomousFlag

INTEGER{true(1),false(2)}

Read-only

Autonomous address configuration flag.

The values are as follows:

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.7.1.5

ipv6AddrPrefixAdvPreferredLifetime

INTEGER (0..4294967295)

Read-only

It is the length of time in seconds that this prefix will remain preferred, that is time until deprecation.

A value of 4294967295 represents infinity.

The address generated from a deprecated prefix should no longer be used as a source address in new communications, but packets received on such an interface are processed as expected.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.7.1.6

ipv6AddrPrefixAdvValidLifetime

INTEGER (0..4294967295)

Read-only

It is the length of time in seconds that this prefix will remain valid, that is time until invalidation.

A value of 4294967295 represents infinity.

The address generated from an invalidated prefix should not appear as the destination or source address of a packet.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.8.1.1

ipv6AddrAddress

OCTET STRING (SIZE (16))

Not-accessible

The IPv6 address to which this entry's addressing information pertains.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.8.1.2

ipv6AddrPfxLength

INTEGER(0..128)

Read-only

The length of the prefix (in bits) associated with the IPv6 address of this entry.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.8.1.3

ipv6AddrType

INTEGER{stateless(1),stateful(2),unknown(3)}

Read-only

The value of this object identifies the address type.

The values are as follows:

Currently, the return value stateful(2) is supported only.

1.3.6.1.2.1.55.1.8.1.4

ipv6AddrAnycastFlag

INTEGER{true(1),false(2)}

Read-only

This object has the value 'true(1)', if this address is an anycast address and the value 'false(2)' otherwise.

Currently, the return value false(2) is supported only.

1.3.6.1.2.1.55.1.8.1.5

ipv6AddrStatus

INTEGER{preferred(1),deprecated(2),invalid(3),inaccessible(4),unknown(5)}

Read-only

The value of this object identifies the address status.

The values are as follows:

Currently, the return value preferred(1) and inaccessible(4) are supported only.

1.3.6.1.2.1.55.1.11.1.1

ipv6RouteDest

OCTET STRING (SIZE (16))

Not-accessible

This object indicates the destination IPv6 address of this route. This object may not take a multicast address value.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.11.1.2

ipv6RoutePfxLength

INTEGER(0..128)

Not-accessible

The value of this object identifies the prefix length of the destination address.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.11.1.3

ipv6RouteIndex

INTEGER (0..4294967295)

Not-accessible

The value which uniquely identifies the route among the routes to the same network layer destination.

The way this value is chosen is implementation specific but it must be unique for ipv6RouteDest/ipv6RoutePfxLength pair and remain constant for the life of the route.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.11.1.4

ipv6RouteIfIndex

Integer32 (0..2147483647)

Read-only

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 ipv6IfIndex.

For routes of the discard type this value can be zero.

The value ranges from 0 to 2147483647.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.11.1.5

ipv6RouteNextHop

OCTET STRING (SIZE (16))

Read-only

On remote routes, the address of the next system en route; otherwise, ::0.('00000000000000000000000000000000'H in ASN.1 string representation).

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.11.1.6

ipv6RouteType

INTEGER{other(1),discard(2),local(3),remote(4)}

Read-only

The value of this object identifies the route type.

The values are as follows:

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.11.1.7

ipv6RouteProtocol

INTEGER{other(1),local(2),netmgmt(3),ndisc(4),rip(5),ospf(6),bgp(7),idrp(8),igrp(9)}

Read-only

The value of this object identifies the route learning mechanism.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.11.1.8

ipv6RoutePolicy

Integer32

Read-only

The general set of conditions that would cause the selection of one multipath route (set of next hops for a given destination) is referred to as 'policy'. Unless the mechanism indicated by ipv6RouteProtocol specified otherwise, the policy specifier is the 8-bit Traffic Class field of the IPv6 packet header that is zero extended at the left to a 32-bit value.

Protocols defining 'policy' otherwise must either define a set of values which are valid for this object or must implement an integer-instanced policy table for which this object's value acts as an index.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.11.1.9

ipv6RouteAge

INTEGER (0..4294967295)

Read-only

The value of this object identifies the number of seconds since this route was last updated or the route was 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.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.11.1.10

ipv6RouteNextHopRDI

INTEGER (0..4294967295)

Read-only

The value of this object identifies the routing domain ID of the next hop.

The semantics of this object are determined by the routing-protocol specified in the route's ipv6RouteProtocol value.

When this object is unknown or not relevant, its value should be set to zero.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.11.1.11

ipv6RouteMetric

INTEGER (0..4294967295)

Read-only

The value of this object identifies the metric value of this route. The semantics of this metric are determined by the routing protocol specified in the route's ipv6RouteProtocol value.

When this is unknown or not relevant to the protocol indicated by ipv6RouteProtocol, the object value should be set to its maximum value (4294967295).

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.11.1.12

ipv6RouteWeight

INTEGER (0..4294967295)

Read-only

The value of this object identifies the system internal weight of this route. The semantics of this value are determined by the implementation specific rules.

Generally, within routes with the same ipv6RoutePolicy value, the lower the weight value the more preferred is the route.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.11.1.13

ipv6RouteInfo

OBJECT IDENTIFIER

Read-only

A reference to MIB definitions specific to the particular routing protocol which is responsible for this route, as determined by the value specified in the route's ipv6RouteProtocol value.

If this information is not present, its value should be set to the OBJECT IDENTIFIER 0 0, which is a syntactically valid object identifier, and any implementation conforming to ASN.1 and the Basic Encoding Rules must be able to generate and recognize this value.

Currently, the return value 0.0 is supported only.

1.3.6.1.2.1.55.1.11.1.14

ipv6RouteValid

INTEGER{true(1),false(2)}

Read-write

Setting this object to the value 'false(2)' has the effect of invalidating the corresponding entry in the ipv6RouteTable 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 ipv6RouteValid object.

Currently, the maximum access is read-only.

1.3.6.1.2.1.55.1.12.1.1

ipv6NetToMediaNetAddress

OCTET STRING (SIZE (16))

Not-accessible

This object indicates the IPv6 address corresponding to the media dependent physical address.

The fixed length is 16 bytes.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.12.1.2

ipv6NetToMediaPhysAddress

DisplayString (SIZE (0..255))

Read-only

This object indicates the media-dependent physical address.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.12.1.3

ipv6NetToMediaType

INTEGER{other(1),dynamic(2),static(3),local(4)}

Read-only

The value of this object identifies the mapping type.

The values are as follows:

Currently, the return value dynamic(2) and static(3) are supported only.

1.3.6.1.2.1.55.1.12.1.4

ipv6IfNetToMediaState

INTEGER{reachable(1),stale(2),delay(3),probe(4),invalid(5),unknown(6)}

Read-only

The value of this object identifies the status of the neighbor unreachability detection for the interface when the address mapping in this entry is used.

Currently, the return value invalid(5) is not supported.

1.3.6.1.2.1.55.1.12.1.5

ipv6IfNetToMediaLastUpdated

TimeTicks

Read-only

The value of this object identifies the value of sysUpTime when this entry is last updated.

If this entry was updated prior to the last re-initialization of the local network management subsystem, then this object contains a zero value.

This object is implemented as defined in the corresponding MIB files.

1.3.6.1.2.1.55.1.12.1.6

ipv6NetToMediaValid

INTEGER{true(1),false(2)}

Read-write

Setting this object to the value 'false(2)' has the effect of invalidating the corresponding entry in the ipv6NetToMediaTable.

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 ipv6NetToMediaValid object.

Currently, the maximum access is read-only; the return value true(1) is supported only.

1.3.6.1.2.1.55.2.0.1

ipv6IfStateChange

An ipv6IfStateChange notification signifies that there has been a change in the state of an ipv6 interface.

This notification should be generated when the interface's operating status transitions to or from the up(1) state.

This object is implemented as defined in the corresponding MIB files.