SNMP Management: Organization and Information Model In the Name of the Most High SNMP Management: Organization and Information Model by Behzad Akbari Fall 2011

Overview SNMP is the most widely used network management protocol When we say SNMP management, we are really referring to Internet management. SNMP management model: Organization Model Relationship between network element, agent, and manager Hierarchical architecture Information Model Uses ASN.1 syntax SMI (Structure of Management Information MIB ( Management Information Base) Communication Model Transfer syntax SNMP over TCP/IP Communication services addressed by messages Security framework community-based model

Managed LAN NMS on subnet 192.168.252.1 manages the router and the hubs on subnet 172.16.46.1 across the backbone network Figure 4.1 A Managed LAN Network

Managed Hubs: System Information Information obtained querying the hubs Data truly reflects what is stored in the hub Title: System Information: 172.16.46.2 Name or IP Address: 172.16.46.2 System Name: System Description: 3Com LinkBuilder FMS, SW version:3.02 System Contact: System Location: System Object ID: .iso.org.dod.internet.private.enterprises.43.1.8.5 System Up Time: (2475380437) 286 days, 12:03:24.37 Title: System Information: 172.16.46.3 Name or IP Address: 172.16.46.3 System Name: System Description: 3Com LinkBuilder FMS, SW version:3.12 System Contact: System Location: System Object ID: .iso.org.dod.internet.private.enterprises.43.1.8.5 System Up Time: (3146735182) 364 days, 12:55:51.82

Managed Router: System Information Title: System Information: router1.gatech.edu Name or IP Address: 172.16.252.1 System Name: router1.gatech.edu System Description: Cisco Internetwork Operating System Software : IOS (tm) 7000 Software (C7000-JS-M), Version : 11.2(6),RELEASE SOFTWARE (ge1) : Copyright (c) 1986-1997 by Cisco Systems, Inc. : Compiled Tue 06-May-97 19:11 by kuong System Contact: System Location: System Object ID: iso.org.dod.internet.private.enterprises.cisco.ciscoProducts.cisco 7000 System Up Time: (315131795) 36 days, 11:21:57.95

Managed Hub: Port Addresses Information acquired by the NMS on hub interfaces Index refers to the interface on the hub Link address is the MAC address The second row data is a serial link

Managed Router: Port Addresses Information acquired by NMS on the router interfaces Index refers to the interface on the router LEC is the LAN emulation card Ethernet 2/0 interface refers to the interface card 2 and port 0 in that card

Internet Management History 1970s: Advanced Research Project Agency Network (ARPANET) comes up with Internet control Message Protocol (ICMP) Internet Engineering Task Force (IETF) 1990 SNMPv1 1995 SNMPv2 1998 SNMPv3 Internet documents: Request for Comments (RFC) IETF STD Internet Standard FYI For your information

SNMP Related RFCs Figure 4.4 SNMP Document Evolution

Organization Model Describes components of a network management system Focuses on functions and infrastructure Objects are network elements such as hubs, bridges, routers, etc. Managed elements have a process running on them called an agent Manager queries the agent, gets information, processes it and stores it in the MIB MIB SNMP Manager agent agent Managed Objects Unmanaged Objects A simplified hierarchical (2-tier) setup

Organization Model Multiple managers, 1 agent An agent responds to any management system that communicates with it using SNMP A NMS provided by a vendor is in a better position to manage, monitor and configure all NEs coming from that same vendor MIB SNMP Manager SNMP Manager Managed Object agent Managed Objects Managers may have restricted access to managed objects

Organization Model Limiting the data that a manager wishes to obtain! RMON (Remote Monitoring): acts as an agent and a manager RMON gathers data from MO, analyses the data, and stores the data Communicates the statistics to the manager MIB SNMP Manager SNMP Manager Managed Object agent Managed Objects RMON Probe Managers may have restricted access to managed objects 3-tier architecture

Organization Model Proxy server converts non-SNMP data from non-SNMP objects to SNMP compatible objects and messages MIB SNMP Manager Proxy Server Managed Object agent Wireless LAN Managed Objects unmanaged Objects

System Overview Manages objects SNMP messages SNMP Manager Application Get-Response Get-Request GetNext-Request Set-Request Trap UDP IP DLC PHY SNMP Agent SNMP agent Physical Medium Manage- ment Data Network or Internet Manages objects SNMP messages Figure 4.9 SNMP Network Management Architecture

SNMP System Architecture Management Station Network Elements (NEs) Host Router Manager Agent Agent SNMP Network Management Protocol SNMP SNMP . . . UDP UDP UDP IP IP IP DL DL DL SNMP Network

SNMP Services Manager Agent(s) Four Services Five SNMP Messages Get, Set, GetNext Request Get Response Trap Manager Agent(s) Four Services Get, Set, GetNext, Trap Five SNMP Messages GetRequest, SetRequest, GetNextRequest, GetResponse, Trap

SNMP Services Get GetNext Set Trap Get Request Get Response Manager Agent GetNext Request Set Request Trap Request Get GetNext Set Trap

SNMP Services (cont.) Get Request: Get-Next Request: Set Request: Retrieve the values of objects in the MIB of an agent. Get-Next Request: Retrieve the values of the next objects in the MIB of an agent. Set Request: Update the values of objects in the MIB of an agent. Trap Request Report extraordinary events to the manager.

Information Model Structure of Management Information (SMI) (RFC 1155, RFC 1212) Managed Object Scalar Aggregate or tabular object Management Information Base (RFC 1213)

Managed Object Object Type Object Instance

Managed Object: Multiple Instances Object Type Object Instance

Object Name Object is uniquely defined by DESCRIPTOR OBJECT IDENTIFIER

Internet Subnodes directory OBJECT IDENTIFIER ::= {internet 1} mgmt OBJECT IDENTIFIER ::= {internet 2} experimental OBJECT IDENTIFIER ::= {internet 3} private OBJECT IDENTIFIER ::= {internet 4}

root 2 1 ccitt iso joint-iso-ccitt 3 2 1 std reg authority org 1.3.6.1.2.1 member body 6 dod 1.3.6.1.2.1.2 1 1.3.6.1.4.1 internet 1 4 2 3 directory mgmt experimental private 1 1 MIB II MIB II enterprises enterprises system 1 interface 2 interface at 3 IP 4 ICMP 5 TCP 6 UDP 7 EGP 8 Trans. 10 SNMP 11

Private MIB Example http://www.iana.org/ Enterprise Number http://www.isi.edu/in-notes/iana/assignments/enterprise-numbers

SNMP ASN.1 Data Type

Primitive Data Types subtype: INTEGER (0..255) OCTET STRING (SIZE 0..255) OCTET STRING (SIZE 8)

Enumerated Special case of INTEGER data type

Defined or Application Data Type

Constructor or Structured Data Type: SEQUENCE List Marker SEQUENCE { <type1>, <type2>,…, <typeN> } IpAddrEntry ::= SEQUENCE { ipAdEntAddr IpAddress, ipAdEntIfIndex INTEGER, ipAdEntNetMask IpAddress, ipAdEntBcastAddr INTEGER, ipAdEntReasmMaxSize INTEGER (0..65535) }

Constructor or Structured Data Type: SEQUENCE OF SEQUENCE OF <entry> where <entry> is a list constructor ipAddrTable OBJECT-TYPE SYNTAX SEQUENCE OF IpAddrEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "The table of addressing information relevant to this entity's IP addresses." ::= { ip 20 }

Example: IP Address Table Each row (table entry) is a sequence: IpAddrEntry. The ipAddrTable table is a sequence of rows (entries), i.e. a sequence of ipAddrEntry.

Encoding Basic Encoding Rules (BER) - Type, Length, and Value (TLV)

SNMP Data Types and Tags Type Tag OBJECT IDENTIFIER UNIVERSAL 6 SEQUENCE UNIVERSAL 16 IpAddress APPLICATION 0 Counter APPLICATION 1 Gauge APPLICATION 2 TimeTicks APPLICATION 3 Opaque APPLICATION 4

Managed Object: Structure

SMIv1, SMIv2 SMIv1: SMIv2: SMI (RFC 1155) Concise MIB (RFC 1212) Trap-Type (RFC 1215) SMIv2: SMIv2 (RFC 2578) Textual Conventions (RFC 2579) Conformance Statements (RFC 2580)

Object-Type Macro (RFC 1155) OBJECT-TYPE MACRO ::= BEGIN TYPE NOTATION ::= "SYNTAX" type (TYPE ObjectSyntax) “ACCESS" Access "STATUS" Status VALUE NOTATION ::= value (VALUE ObjectName) Access ::= "read-only" | "read-write“ | "write-only | "not-accessible" Status ::= "mandatory” | "optional“ | "obsolete" END

OBJECT-TYPE MACRO (RFC1212) BEGIN TYPE NOTATION ::= "SYNTAX" type(ObjectSyntax) "ACCESS" Access "STATUS" Status DescrPart ReferPart IndexPart DefValPart VALUE NOTATION ::= value (VALUE ObjectName)        ObjectName ::= OBJECT IDENTIFIER

OBJECT-TYPE Example sysLocation OBJECT-TYPE SYNTAX DisplayString (SIZE (0..255)) ACCESS read-write STATUS mandatory DESCRIPTION "The physical location of this node (e.g., `telephone closet, 3rd floor')." ::= { system 6 } DisplayString ::= OCTET STRING (SIZE (0..255))

"SYNTAX" type(ObjectSyntax) CHOICE { simple SimpleSyntax, application-wide ApplicationSyntax } SimpleSyntax ::= CHOICE { number INTEGER, string OCTET STRING, object OBJECT IDENTIFIER, empty NULL } ApplicationSyntax ::= CHOICE { address NetworkAddress, counter Counter, gauge Gauge, ticks TimeTicks, arbitrary Opaque }

ApplicationSyntax 0 .. 232-1 NetworkAddress ::= CHOICE { internet IpAddress } IpAddress ::= [APPLICATION 0] IMPLICIT OCTET STRING (SIZE (4)) Counter ::= [APPLICATION 1] IMPLICIT INTEGER (0..4294967295) Gauge ::= [APPLICATION 2] IMPLICIT INTEGER (0..4294967295) TimeTicks ::= [APPLICATION 3] IMPLICIT INTEGER (0..4294967295) Opaque ::= [APPLICATION 4] IMPLICIT OCTET STRING Back to OBJECT TYPE

"ACCESS" Access "STATUS" Status Access ::= "read-only" | "read-write" | "write-only" | "not-accessible Status ::= "mandatory" | "optional" | "obsolete" | "deprecated" Back to OBJECT TYPE

DescrPart DescrPart ::=  DescrPart ::= "DESCRIPTION" value (description DisplayString) | empty ReferPart ::= "REFERENCE" value (reference DisplayString) ReferPart  Back to OBJECT TYPE

DefValPart DefValPart ::= "DEFVAL" "{" value (defvalue ObjectSyntax) "}" | empty Example: ifNumber OBJECT-TYPE SYNTAX INTEGER ACCESS read-only STATUS mandatory DEFVAL 1 DESCRIPTION "The number of network interfaces (regardless of their current state) present on this system.“ ::= { interfaces 1 } Back to OBJECT TYPE

IndexPart IndexPart ::= "INDEX" "{" IndexTypes "}" IndexTypes ::= value (indexobject ObjectName) | type (indextype) IndexSyntax ::= CHOICE { number INTEGER (0..MAX), string OCTET STRING, object OBJECT IDENTIFIER, address NetworkAddress, ipAddress IpAddress }

instance-identifier (INDEX) integer-valued 3  3 string-valued, fixed-length strings ‘004096563c2e’H  0.64.150.86.60.46 string-valued, variable-length strings “IIS Admin”  9.73.73.83.32.65.100.109.105.110 object identifier-valued 1.3.6.1.2  5.1.3.6.1.2 NetworkAddress-valued 163.22.20.16  1.163.22.20.16 IpAddress-valued 163.22.20.16  163.22.20.16

Index - variable-length string svSvcTable OBJECT-TYPE SYNTAX SEQUENCE OF SvSvcEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "A list of service entries describing network services installed on this server.“ ::= { server 3 } svSvcEntry OBJECT-TYPE SYNTAX SvSvcEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "The names of the network services installed on this server." INDEX { svSvcName } ::= { svSvcTable 1 } Back to OBJECT TYPE

OBJECT-TYPE Example dot1dBasePortEntry OBJECT-TYPE SYNTAX Dot1dBasePortEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "A list of information for each port of the bridge." REFERENCE "IEEE 802.1D-1990: Section 6.4.2, 6.6.1" INDEX { dot1dBasePort } ::= { dot1dBasePortTable 1 }

Aggregate Object A group of objects Also called tabular objects Can be represented by a table with Columns of objects Rows of instances Table of Objects List of Objects Objects

Aggregate M.O. Macro: Table Object ipAddrTable OBJECT-TYPE SYNTAX SEQUENCE OF IpAddrEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "The table of addressing information relevant to this entity's IP addresses." ::= {ip 20}

Aggregate M.O. Macro: Entry Object ipAddrEntry OBJECT-TYPE SYNTAX IpAddrEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "The addressing information for one of this entity's IP addresses." INDEX { ipAdEntAddr } ::= { ipAddrTable 1 } ipAddrEntry: OBJECT-TYPE IpaddrEntry: SYNTAX

Aggregate M.O. Macro: Entry Object IpAddrEntry ::= SEQUENCE { ipAdEntAddr IpAddress, ipAdEntIfIndex INTEGER, ipAdEntNetMask IpAddress, ipAdEntBcastAddr INTEGER, ipAdEntReasmMaxSize INTEGER (0..65535) }

Aggregate M.O. Macro: Columnar Objects ipAdEntAddr OBJECT-TYPE SYNTAX IpAddress ACCESS read-only STATUS mandatory DESCRIPTION "The IP address to which this entry's addressing information pertains.” ::= { ipAddrEntry 1 }

Tabular Representation of Aggregate Object

Tabular Representation of Aggregate Object

Multiple Instances of Aggregate Managed Object

Example

Identification of Managed Objects Use Object Identifier (OID) OID = Object Type OID . Instance Identifier Object Type OID: Each Object type has a unique OID Instance Identifier: Identify instances of object type E.g .mib-2.interface.ifTable.ifEntry.ifDescr.2

Two Kinds of Managed Objects Type-Specific Objects: sysDescr OBJECT-TYPE SYNTAX DisplayString (SIZE(0..255)) ::= {system 1} OID: mib-2.system.1.0 Columnar Objects OID: mib-2.interface.ifTable.ifEntry.ifDescr.2 mib-2.interface.ifTable.ifEntry.ifDescr.6 mib-2.interface.ifTable.ifEntry.ifType.2 mib-2.interface.ifTable.ifEntry.ifType.6

Columnar Objects IfEntry ::= SEQUENCE { ifTable OBJECT-TYPE ifIndex INTEGER, ifDescr DisplayString, ifType INTEGER, … } ifTable OBJECT-TYPE SYNTAX SEQUENCE OF IfEntry … ::= { interface 2 } ifEntry OBJECT-TYPE SYNTAX IfEntry … INDEX {ifIndex } ::= { ifTable 1} ifDescr OBJECT-TYPE SYNTAX DisplayString (SIZE(0..255)) ACCESS read-only STATUS madatory ... ::= {ifEntry 2}

Columnar Objects .ifTable.ifEntry.1 (1.3.6.1.2.1.2.2.1.1) .ifTable.ifEntry.2 (1.3.6.1.2.1.2.2.1.2) .ifTable.ifEntry.3 (1.3.6.1.2.1.2.2.1.3) ifIndex ifDescr ifType . . . 1 le0 6 . . . 6 llc0 1 . . . 7 lo0 24 . . . 9 le1 6 . . . 1.3.6.1.2.1.2.2.1.2.6 1.3.6.1.2.1.2.2.1.3.7

Index in MIB II ifEntry {ifIndex} atEntry {atNetIfIndex, atNetAddress} ipAddrEntry {ipAdEntAddr } ipRouteEntry {ipRouteDest} ipNetToMediaEntry {ipNetToMediaIfIndex, ipNetToMediaNetAddress} tcpConnEntry {tcpConnLocalAddress, tcpConnLocalPort, tcpConnRemoteAddress, tcpConnRemotePort} udpEntry {udpLocalAddress, udpLocalPort} egpNeighEntry {egpNeighAddr}

Index Example To get the state of the TCP connection: 10.10.13.137: 3125 ===> 61.30.91.235: 80 Use snmp_get_req. to get the “tcpConnState” of the tcpConnTable in MIB II. tcpConnState ==> 1.3.6.1.2.1.6.13.1.1 1.3.6.1.2.1.6.13.1.1.10.10.13.137.3125.61.30.91.235.80

tcpConnTable

Management Information Base (MIB) RFC 1213 MIB is a database containing information about elements to be managed For SNMP, the MIB is a structured database (tree) Each resource to be managed is represented by an object Each system (e.g., a router) maintains a MIB that reflects the status of its managed resources A NMS monitors/controls the resources by reading/modifying the values of objects in the MIB

MIB, RFC1213 mgmt (2) directory (1) experimental (3) private (4) Internet {1 3 6 1} mib-2 Internet MIB-II Group system (1) interfaces (2) at (3) ip (4) icmp (5) snmp (11) transmission (10) cmot (9) egp (8) udp (7) tcp (6) Implementation can be done as needed (e.g., objects essential for fault or configuration management are added) If a group is implemented by a vendor, all its components are implemented (e.g. OSPF and all its group objects) <module name> DEFINITIONS ::= BEGIN <imports> <definitions> END

MIB, RFC1213 -- groups in MIB-II RFC1213-MIB DEFINITIONS ::= BEGIN system OBJECT IDENTIFIER ::= { mib-2 1} interfaces OBJECT IDENTIFIER ::= { mib-2 2 } at OBJECT IDENTIFIER ::= { mib-2 3 } ip OBJECT IDENTIFIER ::= { mib-2 4 } icmp OBJECT IDENTIFIER ::= { mib-2 5 } tcp OBJECT IDENTIFIER ::= { mib-2 6 } udp OBJECT IDENTIFIER ::= { mib-2 7 } egp OBJECT IDENTIFIER ::= { mib-2 8 } cmot OBJECT IDENTIFIER ::= { mib-2 9 } transmission OBJECT IDENTIFIER ::= {mib-2 10} snmp OBJECT IDENTIFIER ::= { mib-2 11 } . END RFC1213-MIB DEFINITIONS ::= BEGIN IMPORT mgmt, NetworkAddress, IpAddress, Counter, Gauge, TimeTicks FROM RFC1155-SMI OBJECT-TYPE FROM RFC-1212; -- This MIB module uses the extended -- OBJET-TYPE macro as defined in [14]; -- MIB-II (same prefix as MIB-I) mib-2 OBJECT IDENTIFIER ::= { mgmt 1 } -- textual conventions DisplayString ::= OCTET STRING -- This data type is used to model textual -- information taken from the NVT ASCII character -- set. By convention, objects -- with this syntax are declared as having -- -- SIZE (0..255) PhysAddress ::= -- This data type is used to model media -- addresses. For many types of media, this will -- be in a binary representation. For example, -- an ethernet address would be represented as -- a string of 6 octets.

MIB, System Group sysServices (7) sysLocation (6) sysDescr (1) system -- the System group -- Implementation of the System group is -- mandatory for all systems. If an agent is not -- configured to have a value for any of these -- variables, a string of length 0 is returned. sysDescr OBJECT-TYPE SYNTAX DisplayString (SIZE (0..255)) ACCESS read-only STATUS mandatory DESCRIPTION "A textual description of the entity. ……." ::= { system 1 } sysServices (7) sysLocation (6) sysDescr (1) system (mib-2 1) sysObjectId (2) sysUpTime (3) sysName (5) sysContact (4) sysObjectID OBJECT-TYPE SYNTAX OBJECT IDENTIFIER ACCESS read-only STATUS mandatory DESCRIPTION "The vendor's authoritative identification of the network management subsystem contained in the entity." ::= { system 2 } sysUpTime OBJECT-TYPE SYNTAX TimeTicks ACCESS read-only STATUS mandatory DESCRIPTION "The time (in hundredths of a second) since the network management portion of the system was last reinitialized." ::= { system 3 }

MIB, System Group Fault monitoring: By periodically polling each agent for this value; if the current value is less than the most recent value, then the agent has been restarted since last poll! Programmed by vendor of objects during manufacturing time

MIB, Interface Group ifTable (2) ifNumber (1) interfaces (mib-2 2) ifEntry ifIndex (1) ifDescr (2) ifType (3) ifMtu (4) ifSpeed (5) ifPhysAddress (6) ifAdminstatus (7) ifOperStatus (8) ifLastChange (9) ifInOctets (10) ifInUcastPkts (11) ifSpecific (22) ifOutQLen (21) ifOutErrors (20) ifOutDiscards (19) ifOutNUcastPkts (18) ifOutUcastPkts (17) ifOutOctets (16) ifUnknownProtos (15) ifInErrors (14) ifInDiscards (13) ifInNUcastPkts (12) It specifies the number of interfaces in a network component and the managed objects associated with each interface E.g., Ethernet bridge with many network interface cards Implementation: mandatory interfaces OBJECT IDENTIFIER ::= { mib-2 2 }

MIB, Interface Group ifNumber OBJECT-TYPE SYNTAX INTEGER ifTable (2) ifNumber (1) interfaces (mib-2 2) ifEntry ifNumber OBJECT-TYPE SYNTAX INTEGER ACCESS read-only STATUS mandatory DESCRIPTION "The number of network interfaces (regardless of their current state) present on this system." ::= { interfaces 1 } ifEntry OBJECT-TYPE SYNTAX IfEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "An interface entry containing objects at the sub-network layer and below for a particular interface." INDEX { ifIndex } ::= { ifTable 1 } ifTable OBJECT-TYPE SYNTAX SEQUENCE OF IfEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "A list of interface entries. The number of entries is given by the value of ifNumber." ::= { interfaces 2 } IfEntry ::= SEQUENCE {ifIndex INTEGER, ifDescr DisplayString, ifType INTEGER, ifMtu INTEGER, ifSpeed Gauge, ifPhysAddress PhysAddress, ifAdminStatus INTEGER, ifOperStatus INTEGER, ifLastChange TimeTicks, ifInOctets Counter, ……}

MIB, Interface Group ifTable (2) ifNumber (1) interfaces (mib-2 2) ifEntry ifIndex (1) ifDescr (2) ifType (3) ifMtu (4) ifSpeed (5) ifPhysAddress (6) ifAdminstatus (7) ifOperStatus (8) ifLastChange (9) ifInOctets (10) ifInUcastPkts (11) ifSpecific (22) ifOutQLen (21) ifOutErrors (20) ifOutDiscards (19) ifOutNUcastPkts (18) ifOutUcastPkts (17) ifOutOctets (16) ifUnknownProtos (15) ifInErrors (14) ifInDiscards (13) ifInNUcastPkts (12) Basic information useful for network management such as performance monitoring and fault control Examples 1)-measuring the queue length or the total number of octets into/out of the system-- indicators for detecting congestion 2)- measuring the traffic rate on a given interface! ifInUcastPkts/second, ifOutUcastPkts/second Counter data types, always incrementing!

MIB, IP Group ipRoutingDiscards (23) ip (mib-2 4) ipForwarding (1) ipDefaultTTL (2) ipInReceives (3) ipInHdrErrors (4) ipInAddrErrors (5) ipForwDatagrams (6) ipInUnknownProtos (7) ipInDiscards (8) ipInDelivers (9) ipOutRequests(10) ipNetToMediaTable (22) ipRouteTable (21) ipAddrTable (20) ipFragCreates (19) ipFragFails (18) ipFragOKs (17) ipReasmFails (16) ipReasmOKs (15) ipReasmReqds (14) ipOutDiscards (11) ipReasmTimeout (13) ipOutNoRoutes (12) Contains information relevant to the implementation and operation of IP at a node Routers periodically execute routing algorithms and update routing tables IP Address Table contains table of IP addresses IP Route Table contains an entry for each route IP Network-to-Media Table is address translation table mapping IP addresses to physical addresses

MIB, IP Group Gateway or router TTL in IP header Total # packets ipRoutingDiscards (23) ip (mib-2 4) ipForwarding (1) ipDefaultTTL (2) ipInReceives (3) ipInHdrErrors (4) ipInAddrErrors (5) ipForwDatagrams (6) ipInUnknownProtos (7) ipInDiscards (8) ipInDelivers (9) ipOutRequests(10) ipNetToMediaTable (22) ipRouteTable (21) ipAddrTable (20) ipFragCreates (19) ipFragFails (18) ipFragOKs (17) ipReasmFails (16) ipReasmOKs (15) ipReasmReqds (14) ipOutDiscards (11) ipReasmTimeout (13) ipOutNoRoutes (12) Gateway or router TTL in IP header Total # packets received from interfaces # of discarded datagrams due to header errors

MIB, IP Group ipAddrTable (ip 20) ipAddrEntry (ipAddrTable 1) ipAdEntAddr (1) ipAddrEntry (ipAddrTable 1) ipAdEntReasmMaxSize (5) ipAdEntBcastAddr (4) ipAddrTable (ip 20) ipAdEntIfIndex (2) ipAdEntNetMask (3)

MIB, IP Group Contains information used for Internet routing ipRouteEntry ipRouteTable (1) ipRouteDest (1) ipRouteIfIndex (2) ipRouteMetric1 (3) ipRouteMetric2 (4) ipRouteMetric3 (5) ipRouteInfo (13) ipRouteMetric5 (12) ipRouteMask 11) ipRouteAge (10) ipRouteProto (9) ipRouteMetric4 (6) ipRouteType (8) ipRouteNextHop (7) ipRouteTable (ip 21) Contains information used for Internet routing ipRouteTable information is useful for: configuration monitoring, controlling the routing process as well as fault isolation

MIB, TCP Group Contains info. relevant to the implementation/operation of connection-oriented TCP tcp (mib-2 6) tcpRtoAlgorithm (1) tcpRtoMin (2) tcpRtoMax (3) tcpMaxConn (4) tcpActiveOpens (5) tcpOutRsts (15) tcpInErrors (14) tcpConnTable 13) tcpRetranSegs (12) tcpOutSegs (11) tcpPassiveOpens (6) tcpInSegs (10) tcpCurrEstab (9) tcpAttemptFails (7) tcpEstabResets (8) Timeout algorithm for retransmission Minimum value for retransmission timer # segments retransmitted Maximum value for retransmission timer # segments received # segments sent Maximum nb of TCP connections

MIB, TCP Group tcpConnEntry (1) tcpConnState (1) tcpConnLocalAddress (2) tcpCommRemPort (5) tcpConnRemAddress(4) tcpConnLocalPort (3) tcpConnTable (tcp 13)