Network Working Group R. B. Hibbs INTERNET-DRAFT Pacific Bell G. Waters Nortel Networks February 1999 Dynamic Host Configuration Protocol (DHCP) Server MIB Friday, February 19, 1999, 3:39 PM Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." To learn the current status of any Internet-Draft, please check the "1id-abstracts.txt" listing contained in the Internet-Drafts Shadow Directories on ds.internic.net (US East Coast), nic.nordu.net (Europe), ftp.isi.edu (US West Coast), or munnari.oz.au (Pacific Rim). Copyright Notice Copyright (C) The Internet Society (1999). All Rights Reserved. Abstract This memo defines an experimental portion of the Management Information Base (MIB) for use with network management protocols in the Internet Community. In particular, it defines objects used for the management of Dynamic Host Configuration Protocol (DHCP) and Bootstrap Protocol (BOOTP) servers. Hibbs & Waters Expires: Feb 1999 + 6 months [Page 1] Internet Draft DHCP Server MIB February 1999 Table of Contents 1. Introduction......................................................2 2. Overview..........................................................2 2.1. BOOTP and DHCP Counter Groups................................3 2.2. BOOTP and DHCP Statistics Group..............................3 2.3. Server Configuration Group...................................4 2.4. Response Times and ICMP Echo.................................5 3. Definitions.......................................................5 4. Intellectual Property............................................25 5. Notes............................................................26 5.1. Issues......................................................26 5.2. Changes from Prior Drafts...................................26 6. Acknowledgements.................................................27 7. Security Considerations..........................................27 8. References.......................................................28 9. Editors' Addresses...............................................28 10. Full Copyright Statement........................................29 1. Introduction This memo was produced by the DHCP Working Group and defines a portion of the Management Information Base (MIB) for use with network management protocols in the Internet community. In particular, it describes a set of extensions that DHCP and Bootstrap Protocol (BOOTP) servers implement. Many implementations support both DHCP and BOOTP within a single server and hence this memo describes the MIB for both DHCP and BOOTP servers. This memo is applicable only to IPv4 addresses. This memo does not cover DHCP/BOOTP client nor relay agent extensions: these are possibly the subjects of future investigation. This memo is based on the Internet-standard Network Management Framework as defined by [RFC1902, RFC1903, RFC1904]. Objects defined in this MIB allow access to and control of DHCP Server Software. Servers MAY also provide additional management capabilities through the use of the Applications MIB [RFC2287]. The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. 2. Overview In the tradition of the Simple Network Management Protocol (SNMP) the minimum number of objects possible are defined in this MIB, while Hibbs & Waters Expires: Feb 1999 + 6 months [Page 2] Internet Draft DHCP Server MIB February 1999 still providing as rich a set of management information as possible. An object is left out of this MIB when it can be derived from other objects that are provided. Further to the tradition of the SNMP, computationally intense operations are left to the domain of the management station. Thus, this MIB provides a set of objects from which other management information may be derived. The examples provided in the following sections are not meant to be comprehensive, they are merely illustrative of the potential uses of the objects defined by this MIB. 2.1. BOOTP and DHCP Counter Groups This section describes some of the management information that may be derived from the objects provided in the counter groups. The total number of valid DHCP packets received by the server is computed as the sum of the dhcpCountDiscovers, dhcpCountRequests, dhcpCountReleases, dhcpCountDeclines, and dhcpCountInforms objects. The total number of valid packets (BOOTP and DHCP) received is computed as the total number of valid DHCP packets plus the value of the bootpCountRequests object. The total number of packets received is computed as the total number of valid packets plus bootpCountInvalids and dhcpCountInvalids. Similar to the received computations, the total number of DHCP packets sent by the server is computed as the sum of the dhcpCountOffers, dhcpCountAcks, and dhcpCountNacks objects. The number of packets (BOOTP and DHCP) sent by the server is computed as the total number of DHCP packets sent plus the value of the bootpCountReplies object. 2.2. BOOTP and DHCP Statistics Group This section describes some of the management information that may be derived from the objects provided in the statistics group. Given time 1 (t1) and time 2 (t2) greater than t1, the mean inter- arrival time of valid DHCP messages for the interval t1 to t2 can be computed as (dhcpStatLastArrivalTime at t2 minus dhcpStatLastArrivalTime at t1) divided by (valid DHCP received packet count at t2 minus valid DHCP received packet count at t1). Under the simplifying assumption that the capture of packet counts and times is discontinuous (that is, for the measurement interval the captured data represents the complete set for the server) the variance of the mean may be computed as (dhcpStatSumSquaresArrivalTime at t2 less dhcpStatSumSquaresArrivalTime at t1) divided by (valid DHCP received packet count at t2 less valid DHCP received packet count at t1). Standard deviation of the mean is the square root of the variance. Hibbs & Waters Expires: Feb 1999 + 6 months [Page 3] Internet Draft DHCP Server MIB February 1999 Calculation of statistics for message response time is entirely similar to the calculations for inter-arrival time, except that the response time objects are used for the calculations. Calculation of statistics for BOOTP is similar to the calculations for DHCP, except that the similar objects from the bootStatistics group are used instead of the objects from dhcpStatistics group. 2.3. Server Configuration Group The server configuration group contains objects that describe the configuration information that is contained in the server. Some of the configuration information is static (e.g.: a statically configured IP address) and some of the configuration is dynamic (e.g.: an assigned DHCP lease). The intent of the server configuration group is to be able to read the server's configuration. Mechanisms outside of the SNMP are currently in use (e.g.: vendor defined solutions) and are being standardized (e.g.: the Directory Enabled Networks [DEN] initiative) to update a server's configuration. The configuration information provides a minimal set of information that most servers should be able to provide. Each row of the serverSubnetTable lists the subnet, the subnet mask, and the subnet that is equivalent to this subnet. Equivalence is defined as more than one subnet being present on the same physical media as some other subnet. The serverRangeTable lists the start and end IP addresses of the ranges and the subnet which the range is a member of. The serverRangeInUse object indicates the amount of the range that is currently in use, either through dynamic allocation or being reserved. The range size can be computed by taking the difference of the serverRangeStart and serverRangeEnd objects. The serverAddressTable provides information about the static and dynamic addresses that the server contains in its configuration. Addresses may be: o Static, in which case they are predefined though the server's configuration. Static addresses may or may not have been previously served by the server; o Dynamic, in which case the server has served the addresses at least once. Leases which have expired MAY appear in the address list; o Configuration-reserved, in which case the address is not available for the server to allocate to a client. A configuration-reserved address is one that has been reserved by the administrator. An example of a configuration-reserved address is an address that is assigned to a client, not through DHCP (e.g.: statically assigned), and the address is within a DHCP range; and, Hibbs & Waters Expires: Feb 1999 + 6 months [Page 4] Internet Draft DHCP Server MIB February 1999 o Server-reserved, in which case the server has taken the address out of use. Examples of server-reserved addresses are those which have been declined (i.e.: through a DHCPDECLINE) by a client or those which have responded to an ICMP echo before they were assigned. The protocol used to allocate the address may be determined from the serverAddressServedProtocol object. This object indicates whether the address has never been served (value of none(1)), or, whether BOOTP or DHCP was used to allocate the address. 2.4. Response Times and ICMP Echo According to [RFC2131], servers SHOULD try to determine if an address is in use before assigning it. Some servers choose not to perform this check, letting the client determine for itself if the address is in use. Other servers perform an ICMP echo (Ping) just prior to assigning an address. Servers that perform a Ping before responding to a DHCPDISCOVER should not include in the response time the time from when the Ping was transmitted until the time that either a response was received or that the server timed out waiting for a response. 3. Definitions DHCP-SERVER-MIB DEFINITIONS ::= BEGIN IMPORTS Counter64, Counter32, Gauge32, Unsigned32, mib-2, MODULE-IDENTITY, OBJECT-TYPE, OBJECT-IDENTITY, IpAddress FROM SNMPv2-SMI TEXTUAL-CONVENTION, RowStatus, DisplayString, TruthValue, DateAndTime FROM SNMPv2-TC MODULE-COMPLIANCE, OBJECT-GROUP FROM SNMPv2-CONF; dhcp OBJECT-IDENTITY STATUS current DESCRIPTION "The dhcp branch in the standard network management framework." ::= { mib-2 ?? } -- IANA will make official assignment dhcpServerMib MODULE-IDENTITY LAST-UPDATED "9902190000Z" ORGANIZATION "IETF DHCP Working Group" CONTACT-INFO " Richard Barr Hibbs Hibbs & Waters Expires: Feb 1999 + 6 months [Page 5] Internet Draft DHCP Server MIB February 1999 Postal: Pacific Bell 666 Folsom Street, Room 1225 San Francisco, CA 94107-1384 USA Tel: +1 415-545-1576 Fax: +1 415-543-3539 Email: rbhibbs@pacbell.com Glenn Waters Postal: Nortel Networks, Inc. 310-875 Carling Avenue Ottawa, Ontario K1S 5P1 Canada Tel: +1 613-798-4925 Email: gww@nortelnetworks.com " DESCRIPTION "The MIB module for entities implementing the server side of the Bootstrap Protocol (BOOTP) and the Dynamic Host Configuration protocol (DHCP) for Internet Protocol version 4 (IPv4)." ::= { dhcp 1 } dhcpServerMibObjects OBJECT-IDENTITY STATUS current DESCRIPTION "DHCP Server MIB objects are all defined in this branch." ::= { dhcpServerMib 1 } serverSystem OBJECT-IDENTITY STATUS current DESCRIPTION "Group of objects that are related to the overall system." ::= { dhcpServerMibObjects 1 } bootpCounters OBJECT-IDENTITY STATUS current DESCRIPTION "Group of objects that count various BOOTP events." ::= { dhcpServerMibObjects 2 } dhcpCounters OBJECT-IDENTITY STATUS current DESCRIPTION "Group of objects that count various DHCP events." ::= { dhcpServerMibObjects 3 } bootpStatistics OBJECT-IDENTITY STATUS current DESCRIPTION "Group of objects that measure various BOOTP statistics." ::= { dhcpServerMibObjects 4 } Hibbs & Waters Expires: Feb 1999 + 6 months [Page 6] Internet Draft DHCP Server MIB February 1999 dhcpStatistics OBJECT-IDENTITY STATUS current DESCRIPTION "Group of objects that measure various DHCP statistics." ::= { dhcpServerMibObjects 5 } serverConfiguration OBJECT-IDENTITY STATUS current DESCRIPTION "Objects that contain pre-configured and dynamic configuration information." ::= { dhcpServerMibObjects 6 } bootpClients OBJECT-IDENTITY STATUS current DESCRIPTION "Objects that map bootp clients to IP addresses." ::= { dhcpServerMibObjects 7 } dhcpClients OBJECT-IDENTITY STATUS current DESCRIPTION "Objects that map DHCP clients to IP addresses." ::= { dhcpServerMibObjects 8 } dhcpServerConformance OBJECT-IDENTITY STATUS current DESCRIPTION "DHCP Server MIB objects are all defined in this branch." ::= { dhcpServerMib 1 } -- Textual conventions defined by this memo DhcpTimeInterval ::= TEXTUAL-CONVENTION STATUS current DESCRIPTION "The number of milli-seconds that has elapsed since some epoch. Systems that cannot measure events to the milli-second resolution SHOULD round this value to the next available resolution that the system supports." SYNTAX Unsigned32 -- serverSystem Group serverSystemDescr OBJECT-TYPE SYNTAX DisplayString (SIZE (0..255)) MAX-ACCESS read-only STATUS current DESCRIPTION Hibbs & Waters Expires: Feb 1999 + 6 months [Page 7] Internet Draft DHCP Server MIB February 1999 "A textual description of the server. This value should include the full name and version identification of the server. This string MUST contain only printable NVT ASCII characters." ::= { serverSystem 1 } serverSystemObjectID OBJECT-TYPE SYNTAX OBJECT IDENTIFIER MAX-ACCESS read-only STATUS current DESCRIPTION "The vendor's authoritative identification of the network management subsystem contained in this entity. This value is allocated within the SMI enterprise subtree (1.3.6.1.4.1) and provides an easy and unambiguous means for determining 'what kind of server' is being managed. For example, if vendor 'VeryBigServers, Inc.' was assigned the subtree 1.3.6.1.4.1.4242, it may assign the identifier 1.3.6.1.4.1.4242.1.1 to its `Hercules DHCP Server'." ::= { serverSystem 2 } -- bootpCounters Group bootpCountRequests OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of packets received that contain a Message Type of 1 (BOOTREQUEST) in the first octet and do not contain option number 53 (DHCP Message Type) in the options." ::= { bootpCounters 1 } bootpCountInvalids OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of packets received that do not contain a Message Type of 1 (BOOTREQUEST) in the first octet or are not valid BOOTP packets (e.g.: too short, invalid field in packet header)." ::= { bootpCounters 2 } bootpCountReplies OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of packets sent that contain a Message Type of 1 (BOOTREQUEST) in the first octet and do not contain option number 53 (DHCP Message Type) in the options." Hibbs & Waters Expires: Feb 1999 + 6 months [Page 8] Internet Draft DHCP Server MIB February 1999 ::= { bootpCounters 3 } bootpCountDroppedUnknownClients OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of BOOTP packets dropped due to the server not recognizing or not providing service to the hardware address received in the incoming packet." ::= { bootpCounters 4 } bootpCountDroppedNotServingSubnet OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of BOOTP packets dropped due to the server not being configured or not otherwise able to serve addresses on the subnet from which this message was received." ::= { bootpCounters 5 } -- dhcpCounters Group dhcpCountDiscovers OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of DHCPDISCOVER (option 53 with value 1) packets received." ::= { dhcpCounters 1 } dhcpCountRequests OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of DHCPREQUEST (option 53 with value 3) packets received." ::= { dhcpCounters 2 } dhcpCountReleases OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of DHCPRELEASE (option 53 with value 7) packets received." ::= { dhcpCounters 3 } Hibbs & Waters Expires: Feb 1999 + 6 months [Page 9] Internet Draft DHCP Server MIB February 1999 dhcpCountDeclines OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of DHCPDECLINE (option 53 with value 4) packets received." ::= { dhcpCounters 4 } dhcpCountInforms OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of DHCPINFORM (option 53 with value 8) packets received." ::= { dhcpCounters 5 } dhcpCountInvalids OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of DHCP packets received whose DHCP message type (i.e.: option number 53) is not understood or handled by the server." ::= { dhcpCounters 6 } dhcpCountOffers OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of DHCPOFFER (option 53 with value 2) packets sent." ::= { dhcpCounters 7 } dhcpCountAcks OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of DHCPACK (option 53 with value 5) packets sent." ::= { dhcpCounters 8 } dhcpCountNacks OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of DHCPNACK (option 53 with value 6) packets sent." ::= { dhcpCounters 9 } Hibbs & Waters Expires: Feb 1999 + 6 months [Page 10] Internet Draft DHCP Server MIB February 1999 dhcpCountDroppedUnknownClient OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of DHCP packets dropped due to the server not recognizing or not providing service to the client-id and/or hardware address received in the incoming packet." ::= { dhcpCounters 10 } dhcpCountDroppedNotServingSubnet OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of DHCP packets dropped due to the server not being configured or not otherwise able to serve addresses on the subnet from which this message was received." ::= { dhcpCounters 11 } -- bootpStatistics group bootpStatMinArrivalInterval OBJECT-TYPE SYNTAX DhcpTimeInterval MAX-ACCESS read-write STATUS current DESCRIPTION "The minimum amount of time between receiving two BOOTP messages. A message is received at the server when the server is able to begin processing the message. This typically occurs immediately after the message is read into server memory. If no messages have been received, then this object contains a zero value." ::= { bootpStatistics 1 } bootpStatMaxArrivalInterval OBJECT-TYPE SYNTAX DhcpTimeInterval MAX-ACCESS read-write STATUS current DESCRIPTION "The maximum amount of time between receiving two BOOTP messages. A message is received at the server when the server is able to begin processing the message. This typically occurs immediately after the message is read into server memory. If no messages have been received, then this object contains a zero value." ::= { bootpStatistics 2 } bootpStatLastArrivalTime OBJECT-TYPE SYNTAX DateAndTime Hibbs & Waters Expires: Feb 1999 + 6 months [Page 11] Internet Draft DHCP Server MIB February 1999 MAX-ACCESS read-only STATUS current DESCRIPTION "The date and time that the last valid BOOTP message was received by the server. Invalid messages do not cause this value to change. If valid no messages have been received, then this object contains a date and time that is all zero." ::= { bootpStatistics 3 } bootpStatSumSquaresArrivalTime OBJECT-TYPE SYNTAX Counter64 MAX-ACCESS read-only STATUS current DESCRIPTION "The sum of the squared BOOTP packet inter-arrival times in micro-seconds. This value may be used to compute the variance and standard deviation of the BOOTP arrival times. Note that a micro-second resolution of this object requires a clock resolution to the milli-second since the square of a milli- second value produces a value with micro-second resolution." ::= { bootpStatistics 4 } bootpStatMinResponseTime OBJECT-TYPE SYNTAX DhcpTimeInterval MAX-ACCESS read-write STATUS current DESCRIPTION "The smallest time interval measured as the difference between the arrival of a BOOTP message at the server and the successful transmission of the response to that message. A message is received at the server when the server is able to begin processing the message. A message is transmitted after the server has no further use for the message. Note that the operating system may still have the message queued internally. The operating system queue time is not to be considered as part of the response time. Invalid messages do not cause this value to change. If no valid messages have been received, then this object contains a zero value." ::= { bootpStatistics 5 } bootpStatMaxResponseTime OBJECT-TYPE SYNTAX DhcpTimeInterval MAX-ACCESS read-write STATUS current DESCRIPTION "The largest time interval measured as the difference between the arrival of a BOOTP message at the server and the successful transmission of the response to that message. A message is received at the server when the server is able to begin processing the message. A message is transmitted after the server has no further use for the message. Note that the operating system may still have the message queued internally. Hibbs & Waters Expires: Feb 1999 + 6 months [Page 12] Internet Draft DHCP Server MIB February 1999 The operating system queue time is not to be considered as part of the response time. Invalid messages do not cause this value to change. If no valid messages have been received, then this object contains a zero value." ::= { bootpStatistics 6 } bootpStatSumResponseTime OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The sum of the response time intervals in milli-seconds where a response time interval is measured as the difference between the arrival of a BOOTP message at the server and the successful transmission of the response to that message. A message is received at the server when the server is able to begin processing the message. A message is transmitted after the server has no further use for the message. Note that the operating system may still have the message queued internally. The operating system queue time is not to be considered as part of the response time. Invalid messages do not cause this value to change. If no valid messages have been received, then this object contains a zero value." ::= { bootpStatistics 7 } bootpStatSumSquaresResponseTime OBJECT-TYPE SYNTAX Counter64 MAX-ACCESS read-only STATUS current DESCRIPTION "The sum of the squared BOOTP packet response times in micro- seconds. This value may be used to compute the variance and standard deviation of the BOOTP response times. Note that a micro-second resolution of this object requires a clock resolution to the milli-second since the square of a milli- second value produces a value with micro-second resolution." ::= { bootpStatistics 8 } -- dhcpStatistics group dhcpStatMinArrivalInterval OBJECT-TYPE SYNTAX DhcpTimeInterval MAX-ACCESS read-write STATUS current DESCRIPTION "The minimum amount of time between receiving two DHCP messages. A message is received at the server when the server is able to begin processing the message. This typically occurs immediately after the message is read into server memory. If no messages have been received, then this object contains a zero value." Hibbs & Waters Expires: Feb 1999 + 6 months [Page 13] Internet Draft DHCP Server MIB February 1999 ::= { dhcpStatistics 1 } dhcpStatMaxArrivalInterval OBJECT-TYPE SYNTAX DhcpTimeInterval MAX-ACCESS read-write STATUS current DESCRIPTION "The maximum amount of time between receiving two DHCP messages. A message is received at the server when the server is able to begin processing the message. This typically occurs immediately after the message is read into server memory. If no messages have been received, then this object contains a zero value." ::= { dhcpStatistics 2 } dhcpStatLastArrivalTime OBJECT-TYPE SYNTAX DateAndTime MAX-ACCESS read-only STATUS current DESCRIPTION "The date and time that the last valid DHCP message was received by the server. Invalid messages do not cause this value to change. If no valid messages have been received, then this object contains a date and time that is all zero." ::= { dhcpStatistics 3 } dhcpStatSumSquaresArrivalTime OBJECT-TYPE SYNTAX Counter64 MAX-ACCESS read-only STATUS current DESCRIPTION "The sum of the squared DHCP packet inter-arrival times in micro-seconds. This value may be used to compute the variance and standard deviation of the DHCP arrival times. Note that a micro-second resolution of this object requires a clock resolution to the milli-second since the square of a milli- second value produces a value with micro-second resolution." ::= { dhcpStatistics 4 } dhcpStatMinResponseTime OBJECT-TYPE SYNTAX DhcpTimeInterval MAX-ACCESS read-write STATUS current DESCRIPTION "The smallest time interval measured as the difference between the arrival of a DHCP message at the server and the successful transmission of the response to that message. A message is received at the server when the server is able to begin processing the message. A message is transmitted after the server has no further use for the message. Note that the operating system may still have the message queued internally. The operating system queue time is not to be considered as part Hibbs & Waters Expires: Feb 1999 + 6 months [Page 14] Internet Draft DHCP Server MIB February 1999 of the response time. Invalid messages do not cause this value to change. If no valid messages have been received, then this object contains a zero value." ::= { dhcpStatistics 5 } dhcpStatMaxResponseTime OBJECT-TYPE SYNTAX DhcpTimeInterval MAX-ACCESS read-write STATUS current DESCRIPTION "The largest time interval measured as the difference between the arrival of a DHCP message at the server and the successful transmission of the response to that message. A message is received at the server when the server is able to begin processing the message. A message is transmitted after the server has no further use for the message. Note that the operating system may still have the message queued internally. The operating system queue time is not to be considered as part of the response time. Invalid messages do not cause this value to change. If no valid messages have been received, then this object contains a zero value." ::= { dhcpStatistics 6 } dhcpStatSumResponseTime OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The sum of the response time intervals in milli-seconds where a response time interval is measured as the difference between the arrival of a DHCP message at the server and the successful transmission of the response to that message. A message is received at the server when the server is able to begin processing the message. A message is transmitted after the server has no further use for the message. Note that the operating system may still have the message queued internally. The operating system queue time is not to be considered as part of the response time. Invalid messages do not cause this value to change. If no valid messages have been received, then this object contains a zero value." ::= { dhcpStatistics 7 } dhcpStatSumSquaresResponseTime OBJECT-TYPE SYNTAX Counter64 MAX-ACCESS read-only STATUS current DESCRIPTION "The sum of the squared DHCP packet response times in micro- seconds. This value may be used to compute the variance and standard deviation of the DHCP response times. Note that a micro-second resolution of this object requires a clock Hibbs & Waters Expires: Feb 1999 + 6 months [Page 15] Internet Draft DHCP Server MIB February 1999 resolution to the milli-second since the square of a milli- second value produces a value with micro-second resolution." ::= { dhcpStatistics 8 } -- serverConfiguration group serverSubnetTable OBJECT-TYPE SYNTAX SEQUENCE OF ServerSubnetEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "A list of subnets that are configured in this server." ::= { serverConfiguration 1 } serverSubnetEntry OBJECT-TYPE SYNTAX ServerSubnetEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "A logical row in the serverSubnetTable." INDEX { serverSubnet } ::= { serverSubnetTable 1 } ServerSubnetEntry ::= SEQUENCE { serverSubnet IpAddress, serverSubnetMask IpAddress, serverSubnetSharedNet IpAddress } serverSubnet OBJECT-TYPE SYNTAX IpAddress MAX-ACCESS not-accessible STATUS current DESCRIPTION "The IP address of the subnet." ::= { serverSubnetEntry 1 } serverSubnetMask OBJECT-TYPE SYNTAX IpAddress MAX-ACCESS read-only STATUS current DESCRIPTION "The subnet mask of the subnet. This MUST be the same as the value of DHCP option 1 offered to clients on this subnet." ::= { serverSubnetEntry 2 } serverSubnetSharedNet OBJECT-TYPE SYNTAX IpAddress MAX-ACCESS read-only STATUS current DESCRIPTION Hibbs & Waters Expires: Feb 1999 + 6 months [Page 16] Internet Draft DHCP Server MIB February 1999 "The IP address of another subnet that is on the same shared media as this subnet. The address of the shared subnet MUST also be configured on this server. The address 0.0.0.0 should be used if this subnet is not shared." ::= { serverSubnetEntry 3 } serverRangeTable OBJECT-TYPE SYNTAX SEQUENCE OF ServerRangeEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "A list of ranges that are configured on this server." ::= { serverConfiguration 2 } serverRangeEntry OBJECT-TYPE SYNTAX ServerRangeEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "A logical row in the serverRangeTable." INDEX { serverRangeStart } ::= { serverRangeTable 1 } ServerRangeEntry ::= SEQUENCE { serverRangeStart IpAddress, serverRangeEnd IpAddress, serverRangeSubnetMask IpAddress, serverRangeInUse Gauge32, serverRangeOutstandingOffers Gauge32 } serverRangeStart OBJECT-TYPE SYNTAX IpAddress MAX-ACCESS not-accessible STATUS current DESCRIPTION "The IP address of the first address in the range. The value of range start must be less than or equal to the value of range end." ::= { serverRangeEntry 1 } serverRangeEnd OBJECT-TYPE SYNTAX IpAddress MAX-ACCESS read-only STATUS current DESCRIPTION "The IP address of the last address in the range. The value of range end must be greater than or equal to the value of range start." ::= { serverRangeEntry 2 } serverRangeSubnetMask OBJECT-TYPE Hibbs & Waters Expires: Feb 1999 + 6 months [Page 17] Internet Draft DHCP Server MIB February 1999 SYNTAX IpAddress MAX-ACCESS read-only STATUS current DESCRIPTION "The subnet mask (DHCP option 1) provided to any client offered an address from this range." ::= { serverRangeEntry 3 } serverRangeInUse OBJECT-TYPE SYNTAX Gauge32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of addresses in this range that are currently in use. This number includes those addresses whose lease has not expired and addresses which have been reserved (either by the server or through configuration)." ::= { serverRangeEntry 4 } serverRangeOutstandingOffers OBJECT-TYPE SYNTAX Guage32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of outstanding DHCPOFFER messages for this range is reported with this value. An offer is outstanding if the server has sent a DHCPOFFER message to a client, but has not yet received a DHCPREQUEST message from the client nor has the server-specific timeout (limiting the time in which a client can respond to the offer message) for the offer message expired." ::= { serverRangeEntry 5 } serverAddressTable OBJECT-TYPE SYNTAX SEQUENCE OF ServerAddressEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "A list of addresses that are known by this server. The list MUST contain addresses that have not expired. The list MUST NOT contain addresses that have never been assigned by the server UNLESS the lease is pre-configured in the server (e.g.: a static lease on a subnet)." ::= { serverConfiguration 3 } serverAddressEntry OBJECT-TYPE SYNTAX ServerAddressEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "A logical row in the serverAddressTable." Hibbs & Waters Expires: Feb 1999 + 6 months [Page 18] Internet Draft DHCP Server MIB February 1999 INDEX { serverAddress } ::= { serverAddressTable 1 } ServerAddressEntry ::= SEQUENCE { serverAddress IpAddress, serverAddressSubnetMask IpAddress, serverAddressRange IpAddress, serverAddressType INTEGER, serverAddressTimeReminaing Unsigned32, serverAddressAllowedProtocol INTEGER, serverAddressServedProtocol INTEGER, serverAddressMacAddress OCTET STRING, serverAddressClientId OCTET STRING, serverAddressHostName DisplayString, serverAddressDomainName DisplayString } serverAddress OBJECT-TYPE SYNTAX IpAddress MAX-ACCESS not-accessible STATUS current DESCRIPTION "The IP address of the entry." ::= { serverAddressEntry 1 } serverAddressSubnetMask OBJECT-TYPE SYNTAX IpAddress MAX-ACCESS read-only STATUS current DESCRIPTION "The subnet mask (DHCP option 1) provided to the client offered this address. The subnet, resulting from logically ANDing the subnet mask with the entry's IP address, must be configured on this server and appear as a row in the dhcpSubnetTable." ::= { serverAddressEntry 2 } serverAddressRange OBJECT-TYPE SYNTAX IpAddress MAX-ACCESS read-only STATUS current DESCRIPTION "The starting IP address (serverRangeStart object) of the range to which this address belongs. If the address does not fall into one of the configured ranges (e.g.: a statically configured address on a subnet) the range may be 0.0.0.0." ::= { serverAddressEntry 3 } serverAddressType OBJECT-TYPE SYNTAX INTEGER { static(1), dynamic(2), configuration-reserved(3), Hibbs & Waters Expires: Feb 1999 + 6 months [Page 19] Internet Draft DHCP Server MIB February 1999 server-reserved(4) } MAX-ACCESS read-only STATUS current DESCRIPTION "The type of this address." ::= { serverAddressEntry 4 } serverAddressTimeRemaining OBJECT-TYPE SYNTAX Unsigned32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of seconds until the lease expires. A value of 4294967295 (i.e.: 0xFFFFFFFF) should be used for leases that have a lease time which is 'infinite' and for BOOTP leases." ::= { serverAddressEntry 5 } serverAddressAllowedProtocol OBJECT-TYPE SYNTAX INTEGER { none(1), bootp(2), dhcp(3), bootp-or-dhcp(4) } MAX-ACCESS read-only STATUS current DESCRIPTION "The type of protocol that is allowed to be used to serve this address. A type of none(1) indicates that the address is not available to be served (e.g.: a reserved address)." ::= { serverAddressEntry 6 } serverAddressServedProtocol OBJECT-TYPE SYNTAX INTEGER { none(1), bootp(2), dhcp(3) } MAX-ACCESS read-only STATUS current DESCRIPTION "The type of protocol that was used when this address was assigned. This object will have the value of none(1) if the address has not been served." ::= { serverAddressEntry 7 } serverAddressMacAddress OBJECT-TYPE SYNTAX OCTET STRING (SIZE (0 | 2..17)) MAX-ACCESS read-only STATUS current DESCRIPTION Hibbs & Waters Expires: Feb 1999 + 6 months [Page 20] Internet Draft DHCP Server MIB February 1999 "The hardware type and hardware address of the client that has been assigned this lease. The first octet of this object contains the hardware type from the 'htype' field of the BOOTP packet and the remaining octets contain the hardware address from the 'chaddr' field of the BOOTP packet. This object may be empty if the address has not been previously served." ::= { serverAddressEntry 8 } serverAddressClientId OBJECT-TYPE SYNTAX OCTET STRING (SIZE (0..255)) MAX-ACCESS read-only STATUS current DESCRIPTION "The client-id of the client that has been assigned this lease. The client-id is the value specified in option 61 (client-id option) when the lease was assigned. This object may be empty if the lease has not been previously assigned or if the client- id option was not specified when the address was assigned." ::= { serverAddressEntry 9 } serverAddressHostName OBJECT-TYPE SYNTAX DisplayString (SIZE (0..64)) MAX-ACCESS read-only STATUS current DESCRIPTION "The host name (DHCP option 12) the client is configured with or if no host name was configured then the host name that the client supplied when requesting an address." ::= { serverAddressEntry 10 } serverAddressDomainName OBJECT-TYPE SYNTAX DisplayString (SIZE (0..255)) -- need correct maximum length MAX-ACCESS read-only STATUS current DESCRIPTION "The domain name (DHCP option 15) assigned to the client." ::= { serverAddressEntry 11 } serverClientTable OBJECT-TYPE SYNTAX SEQUENCE OF ServerClientEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "A list of clients that are known by this server. Details about the clients may be found by indexing into the serverAddressTable using the serverClientAddress object. This table is indexed first by the MAC address of the client and then by the subnet address on which the client resides. The subnet is included as an index since a MAC address is only Hibbs & Waters Expires: Feb 1999 + 6 months [Page 21] Internet Draft DHCP Server MIB February 1999 guaranteed to be unique within a subnet (i.e.: a MAC address is not globally unique)." ::= { bootpClients 1 } serverClientEntry OBJECT-TYPE SYNTAX ServerClientEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "A logical row in the serverClientTable. An entry in this table may be a client that requested an address but was refused (e.g.: not authorized). Servers MAY track these types of clients if desired and may choose to remove such client entries using a server defined algorithm. As an example, a server may choose to keep client request that does not map to an address for a one hour time period before removing that entry from this table." INDEX { serverClientMacAddress, serverClientSubnet } ::= { bootpClientTable 1 } ServerClientEntry ::= SEQUENCE { serverClientTypeAndMacAddress OCTET STRING, serverClientSubnetMask IpAddress, serverClientAddress IpAddress, serverClientLastRequestTime DateAndTime, serverClientLastRequestType INTEGER, serverClientLastResponseType INTEGER } serverClientTypeAndMacAddress OBJECT-TYPE SYNTAX OCTET STRING (SIZE (2..17)) MAX-ACCESS not-accessible STATUS current DESCRIPTION "The hardware type and hardware address of the client that has been assigned this lease. The first octet of this object contains the hardware type from the 'htype' field of the BOOTP packet and the remaining octets contain the hardware address from the 'chaddr' field of the BOOTP packet." ::= { serverClientEntry 1 } serverClientSubnetMask OBJECT-TYPE SYNTAX IpAddress MAX-ACCESS not-accessible STATUS current DESCRIPTION "The subnet mask (DHCP option 1) applied to the client IP." ::= { serverClientEntry 2 } serverClientAddress OBJECT-TYPE SYNTAX IpAddress MAX-ACCESS read-only Hibbs & Waters Expires: Feb 1999 + 6 months [Page 22] Internet Draft DHCP Server MIB February 1999 STATUS current DESCRIPTION "The IP address of the entry. May be used to index into the serverAddressTable. May be 0.0.0.0 if an address is not associated with this client." ::= { serverClientEntry 3 } serverClientLastRequestTime OBJECT-TYPE SYNTAX DateAndTime MAX-ACCESS read-only STATUS current DESCRIPTION "The time when the last request was received." ::= { serverClientEntry 4 } serverClientLastRequestType OBJECT-TYPE SYNTAX INTEGER { dhcpdiscover(1), bootp(2), dhcprequest(3), dhcpdecline(4), unknown(5), dhcprelease(7), dhcpinform(8) } MAX-ACCESS read-only STATUS current DESCRIPTION "The type of the last request that was received for this client." ::= { serverClientEntry 5 } serverClientLastResponseType OBJECT-TYPE SYNTAX INTEGER { bootp(1), dhcpoffer(2), unknown(3), dhcpack(5), dhcpnak(6) } MAX-ACCESS read-only STATUS current DESCRIPTION "The type of the last response that was sent to this client." ::= { serverClientEntry 6 } -- Compliance groups dhcpServerMIBCompliances OBJECT IDENTIFIER ::= { dhcpServerConformance 1 } Hibbs & Waters Expires: Feb 1999 + 6 months [Page 23] Internet Draft DHCP Server MIB February 1999 dhcpServerMIBGroups OBJECT IDENTIFIER ::= { dhcpServerConformance 2 } dhcpServerMIBCompliance MODULE-COMPLIANCE STATUS current DESCRIPTION "Describes the requirements for conformance to the System Application MIB" MODULE -- this module MANDATORY-GROUPS { serverSystemGroup, bootpCountersGroup, dhcpCountersGroup, bootpStatisticsGroup, dhcpStatisticsGroup, serverConfigurationGroup, serverClientsGroup } ::= { dhcpServerMIBCompliances 1 } serverSystemGroup OBJECT-GROUP OBJECTS { serverSystemDescr, serverSystemObjectID } STATUS current DESCRIPTION "" ::= { dhcpServerMIBGroups 1 } bootpCountersGroup OBJECT-GROUP OBJECTS { bootpCountRequests, bootpCountInvalids, bootpCountReplies, bootpCountDroppedUnknownClients, bootpCountDroppedNotServingSubnet } STATUS current DESCRIPTION "" ::= { dhcpServerMIBGroups 2 } dhcpCountersGroup OBJECT-GROUP OBJECTS { dhcpCountDiscovers, dhcpCountRequests, dhcpCountReleases, dhcpCountDeclines, dhcpCountInforms, dhcpCountInvalids, dhcpCountOffers, dhcpCountAcks, dhcpCountNacks, dhcpCountDroppedUnknownClint, dhcpCountDroppedNotServingSubnet } STATUS current DESCRIPTION "" ::= { dhcpServerMIBGroups 3 } bootpStatisticsGroup OBJECT-GROUP OBJECTS { bootpStatMinArrivalInterval, bootpStatMaxArrivalInterval, bootpStatLastArrivalTime, bootpStatSunSquaresArrivalTime, bootpStatMinResponseTime, bootpStatMaxResponseTime, bootpStatSumReponseTime, bootpStatSumSquaresResponseTime } STATUS current DESCRIPTION Hibbs & Waters Expires: Feb 1999 + 6 months [Page 24] Internet Draft DHCP Server MIB February 1999 "" ::= { dhcpServerMIBGroups 4 } dhcpStatisticsGroup OBJECT-GROUP OBJECTS { dhcpStatMinArrivalInterval, dhcpStatMaxArrivalInterval, dhcpStatLastArrivalTime, dhcpStatSumSquaresArrivalTime, dhcpStatMinResponseTime, dhcpStatMaxResponseTime, dhcpStatSumResponseTime, dhcpStatSumSquaresResponseTime } STATUS current DESCRIPTION "" ::= { dhcpServerMIBGroups 5 } serverConfigurationGroup OBJECT-GROUP OBJECTS { serverSubnet, serverSubnetMask, serverSubnetSharedNet, serverRangeStart, serverRangeEnd, serverRangeSubnet, serverRangeInUse, serverRangeOutstandingOffers, serverAddress, serverAddressSubnet, serverAddressRange, serverAddressRange, serverAddressType, serverAddressTimeRemaining, serverAddressAllowedProtocol, serverAddressServedProtocol, serverAddressTypeAndMacAddress, serverAddressClientId, serverAddressHostName, serverAddressDomainName } STATUS current DESCRIPTION "" ::= { dhcpServerMIBGroups 6 } serverClientsGroup OBJECT-GROUP OBJECTS { serverClientMacAddress, serverClientSubnet, serverClientAddress, serverClientLastRequestTime, serverClientLastRequestType, serverClientLastResponseType } STATUS current DESCRIPTION "" ::= { dhcpServerMIBGroups 7 } END 4. Intellectual Property The IETF takes no position regarding the validity or scope of any intellectual property or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; neither does it represent that it has made any effort to identify any such rights. Information on the IETF's procedures with respect to rights in standards-track and standards- related documentation can be found in BCP-11. Hibbs & Waters Expires: Feb 1999 + 6 months [Page 25] Internet Draft DHCP Server MIB February 1999 Copies of claims of rights made available for publication and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF Secretariat. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights which may cover technology that may be required to practice this standard. Please address the information to the IETF Executive Director. 5. Notes This section will be removed when this memo is published as an RFC. 5.1. Issues o what is the best way to reset statistics? o do we need to reset them individually, as groups, or as a whole? o we need a timestamp of when they were reset o should all invalid packets received be collapsed into a single counter for each protocol type (BOOTP and DHCP), or broken out by type of error? o if counted by error type, what is the set of errors that we should use? o perhaps we should develop a common vocabulary (and glossary) for terms such as "abandoned" so that the objects defined and their descriptions aren't misinterpreted by implementers. o do we need to be concerned about the potential size of some of the configuration data tables? Wouldn't it be better to maintain counters for things like number of leases assigned than to expect the management station to calculate the values by reading very large tables to count the number of leases in that state? 5.2. Changes from Prior Drafts The "-01" revision removed the Server Identity section from the proposed MIB, relying on the Application MIB to accomplish the same result. The min/max (inter-arrival and response times) were changed to Unsigned32 so that they could be reset. Sum of inter-arrival and response times was deleted since the management station can easily calculate them. The last arrival time objects were added. Hibbs & Waters Expires: Feb 1999 + 6 months [Page 26] Internet Draft DHCP Server MIB February 1999 The "-03" version incorporated the proposed configuration tables suggested by Ryan Troll of CMU. The "01" revision of this version added three elements to the server subnet table, number of outstanding offers, number of addresses in use, and number of free addresses, as well as changing subnet address to subnet mask in the server address, server range, and client address tables. The client MAC address element of the client address table was separated into a 1-octet hardware type and a 16-octet client hardware address, causing a renumbering of the elements in this table. Clarifying text was added to several element descriptions, and limitations on values, and the reported value when the server did not support the data element were also specified. 6. Acknowledgements This document is the result of work undertaken the by DHCP working group. The authors would like to particularly acknowledge the development team from Carnegie-Mellon University whose work creating a private MIB for their DHCP server inspired the development of this proposal. In particular, many thanks to Ryan Troll who provided a great deal of useful feedback during the development of this MIB. 7. Security Considerations There are a number of management objects defined in this MIB that have a MAX-ACCESS clause of read-write and/or read-create. Such objects may be considered sensitive or vulnerable in some environments. The support for SET operations in a non-secure environment without proper protection can have a negative effect on network operations. SNMPv1 by itself is not a secure environment. Even if the network itself is secure (for example by using IPSec), even then, there is no control as to who on the secure network is allowed to access and GET/SET (read/change/create/delete) the objects in this MIB. It is recommended that the implementers consider the security features as provided by the SNMPv3 framework. Specifically, the use of the User-based Security Model RFC 2274 [RFC2274] and the View-based Access Control Model RFC 2275 [RFC2275] is recommended. It is then a customer/user responsibility to ensure that the SNMP entity giving access to an instance of this MIB, is properly configured to give access to the objects only to those principals (users) that have legitimate rights to indeed GET or SET (change/create/delete) them. Hibbs & Waters Expires: Feb 1999 + 6 months [Page 27] Internet Draft DHCP Server MIB February 1999 8. References [DEN] Directory Enabled Networks Working Group, http://www.universe.digex.net/~murchiso/den. [RFC1902] Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, "Structure of Management Information for Version 2 of the Simple Network Management Protocol (SNMPv2)", RFC 1902, January 1996. [RFC1903] Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, "Textual Conventions for Version 2 of the Simple Network Management Protocol (SNMPv2)", RFC 1903, January 1996. [RFC1904] Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, "Conformance Statements for Version 2 of the Simple Network Management Protocol (SNMPv2)", RFC 1904, January 1996. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", RFC 2119, BCP 14, March 1997. [RFC2131] Droms, R., "Dynamic Host Configuration Protocol", RFC 2131, March 1997. [RFC2132] Alexander, S. and Droms, R., "DHCP Options and BOOTP Vendor Extensions", RFC 2132, March 1997. [RFC2274] Blumenthal, U., and B. Wijnen, "User-based Security Model (USM) for version 3 of the Simple Network Management Protocol (SNMPv3)", RFC 2274, January 1998. [RFC2275] Wijnen, B., Presuhn, R., and K. McCloghrie, "View-based Access Control Model for the Simple Network Management Protocol (SNMP)", RFC 2275, January 1998. [RFC2287] Krupczak, C. and Saperia, J., "Definitions of System-Level Managed Objects for Applications", RFC 2287, February 1998. 9. Editors' Addresses Richard Barr Hibbs Pacific Bell 666 Folsom Street, Room 1225 San Francisco, CA 94107-1384 USA Phone: +1 415-545-1576 Fax: +1 415-543-3539 Email: rbhibbs@pacbell.com Glenn Waters Nortel Networks Hibbs & Waters Expires: Feb 1999 + 6 months [Page 28] Internet Draft DHCP Server MIB February 1999 310-875 Carling Avenue, Ottawa, Ontario K1S 5P1 Canada Phone: +1 613-798-4925 Email: gww@nortelnetworks.com 10. Full Copyright Statement Copyright (C) The Internet Society (1999). All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English. The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns. This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Hibbs & Waters Expires: Feb 1999 + 6 months [Page 29]