MIB-II Applications. Titlepae. Applications & Gateways

Transcription

1 MIB-II Applications Titlepae Applications & Gateways

2 Copyright Notice Document Copyright 2002-present by Aprisma Management Technologies, Inc. All rights reserved worldwide. Use, duplication, or disclosure by the United States government is subject to the restrictions set forth in DFARS (c)(1)(ii) and FAR Liability Disclaimer Aprisma Management Technologies, Inc. ( Aprisma ) reserves the right to make changes in specifications and other information contained in this document without prior notice. In all cases, the reader should contact Aprisma to inquire if any changes have been made. The hardware, firmware, or software described in this manual is subject to change without notice. IN NO EVENT SHALL APRISMA, ITS EMPLOYEES, OFFICERS, DIRECTORS, AGENTS, OR AFFILIATES BE LIABLE FOR ANY INCIDENTAL, INDIRECT, SPECIAL, OR CONSEQUENTIAL DAMAGES WHATSOEVER (INCLUDING BUT NOT LIMITED TO LOST PROFITS) ARISING OUT OF OR RELATED TO THIS MANUAL OR THE INFORMATION CONTAINED IN IT, EVEN IF APRISMA HAS BEEN ADVISED OF, HAS KNOWN, OR SHOULD HAVE KNOWN, THE POSSIBILITY OF SUCH DAMAGES. Trademark, Service Mark, and Logo Information SPECTRUM, IMT, and the SPECTRUM IMT/VNM logo are registered trademarks of Aprisma Management Technologies, Inc., or its affiliates. APRISMA, APRISMA MANAGEMENT TECHNOLOGIES, the APRISMA MANAGEMENT TECHNOLOGIES logo, MANAGE WHAT MATTERS, DCM, VNM, SpectroGRAPH, SpectroSERVER, Inductive Modeling Technology, Device Communications Manager, SPECTRUM Security Manager, and Virtual Network Machine are unregistered trademarks of Aprisma Management Technologies, Inc., or its affiliates. For a complete list of Aprisma trademarks, service marks, and trade names, go to All referenced trademarks, service marks, and trade names identified in this document, whether registered or unregistered, are the intellectual property of their respective owners. No rights are granted by Aprisma Management Technologies, Inc., to use such marks, whether by implication, estoppel, or otherwise. If you have comments or concerns about trademark or copyright references, please send an to spectrum-docs@aprisma.com; we will do our best to help. Restricted Rights Notice (Applicable to licenses to the United States government only.) This software and/or user documentation is/are provided with RESTRICTED AND LIMITED RIGHTS. Use, duplication, or disclosure by the government is subject to restrictions as set forth in FAR (June 1987) Alternate III(g)(3) (June 1987), FAR (June 1987), or DFARS (c)(1)(ii) (June 1988), and/or in similar or successor clauses in the FAR or DFARS, or in the DOD or NASA FAR Supplement, as applicable. Contractor/manufacturer is Aprisma Management Technologies, Inc. In the event the government seeks to obtain the software pursuant to standard commercial practice, this software agreement, instead of the noted regulatory clauses, shall control the terms of the government's license. Virus Disclaimer Aprisma makes no representations or warranties to the effect that the licensed software is virus-free. Aprisma has tested its software with current virus-checking technologies. However, because no antivirus system is 100 percent effective, we strongly recommend that you write-protect the licensed software and verify (with an antivirus system in which you have confidence) that the licensed software, prior to installation, is virus-free. Contact Information Aprisma Management Technologies, Inc. 273 Corporate Drive Portsmouth, NH Phone: U.S. toll-free: Web site: Device Management Page 2 MIB-II Applications

3 Contents INTRODUCTION 4 Purpose and Scope...4 Other Applications Documents...4 Summary of This Document...5 SNMP APPLICATION 6 SNMP Application Views...6 MIB-II Performance View...6 SNMP Agent Detail View...7 Packet Breakdown (Pie Chart)...7 Error Breakdown...7 Discard Breakdown (Pie Chart)...8 SNMP Agent Detail 2 View...9 Receive Breakdown (Pie Chart)...9 Transmit Breakdown...10 IP APPLICATIONS 12 IP Application Views...13 IP Configuration View...13 IP Routing View...13 IP Routing Detail View...15 IP Address Table...16 IP Fragmentation View...17 IP Reassembly View...17 IP Net-To-Media Table View...18 IP Net to Media Table...18 ICMP APPLICATION 19 ICMP Detail View ICMP Application Detail View Packet Breakdown (Pie Chart) Error Breakdown (Pie Chart) Discard Breakdown (Pie Chart) TCP APPLICATION 22 TCP Views TCP Application Configuration View TCP Connection Table View...23 TCP Detail View...24 Packet Breakdown (Pie Chart) Error Breakdown (Pie Chart) SYSTEM APPLICATION 25 System Configuration View...25 UDP APPLICATION 26 UDP Views UDP Listener Table View...26 UDP Performance View...27 UDP Detail View...27 INDEX 28 Device Management Page 3 MIB-II Applications

4 Introduction This section summarizes the contents of this document, which is one of a set of documents describing SPECTRUM applications. This section also provides references to the other applications documents. This section covers the following topics: Purpose and Scope Other Applications Documents Summary of This Document (Page 5) Purpose and Scope This document defines the fields displayed in the views associated with a category of SPECTRUM applications called MIB-II applications, which includes such applications as SNMP, TCP, and ICMP. In all cases, the views and fields described in this document are accessed from the Icon Subviews menu of the application models displayed in the Main Applications view. Other Applications Documents Table 1 lists the documents that cover the other categories of SPECTRUM applications. In addition to the documents listed in the table, the document MIBs and the Applications View provides an introduction to the Application view and defines MIB functions in network management. All of these documents (and others) are available on the Aprisma Web site at: Table 1: Document Title Other Applications Documents Typical Applications Technology Applications APPN, ATM, DHCP Bridging Applications Transmission Applications Routing Applications Spanning Tree, PPP Bridging FDDI, Token Ring, Ethernet OSPF, VRRP, BGP4 Device Management Page 4 MIB-II Applications

5 Introduction Summary of This Document Summary of This Document The rest of this document describes the following applications: SNMP Application (Page 6) IP Applications (Page 12) ICMP Application (Page 19) TCP Application (Page 22) UDP Application (Page 26) System Application (Page 25) Some older devices support MIB-1 attributes; most newer devices support MIB-II attributes. Wherever applicable in this document, views using MIB-II attributes description will be described. For more information on Management Information Bases (MIBs), refer to the Introduction to MIBs and the Application View. For information on Performance or Detail view statistics, refer to the SPECTRUM Views documentation. Device Management Page 5 MIB-II Applications

6 SNMP Application This section provides access information to the MIB-II SNMP Application views and descriptions of the application s views. Network management protocols have more complex dependencies than other protocols. MIB- II acts as an umbrella for a set of internetstandard groups including SNMP, described in this section. SNMP is the standard protocol used to monitor IP gateways and networks to which they attach. SNMP defines a set of variables that the gateway contains, and specifies gateway operations as being a side effect to storing data variables. SNMP Application Views SNMP depends upon Abstract Syntax Notation One (ASN.1) and a transport protocol. If the SNMP processes in both the manager and agent respond to the console, the ASN.1 encoding at the Application layer provides the proper syntax for the SNMP message. ASN.1 defines the following: abstract syntaxes of application data structure of the application and presentation of Protocol Data Units (PDUs) the MIB for SNMP and OSI (Open System Interconnection) systems management SPECTRUM s SNMP2Agent pools information from all SNMP subgroups. The MIB_II SNMP group is extensible, allowing administrators to add network management functions and separate the management architecture from the architecture of hardware devices. The SNMP Application Views and fields are described below. MIB-II Performance View Access: From the Icon Subviews menu for the SNMP2_Agent Application icon, select Performance. The MIB-II Performance View displays a breakdown of statistics for the application. This view contains a Multi-Attribute Line Graph that provides a color-coded indication of device activity. Device Management Page 6 MIB-II Applications

7 SNMP Application Detail Click this button to display the SNMP Agent Detail View, which is described below. SNMP Agent Detail View Access: From the Icon Subviews menu for the SNMP2_Agent Application icon, select Detail1, or click on the Detail button in the MIB-II Performance View. The SNMP Agent Detail View provides color-coded pie charts (Packet, Error, and Discard Breakdown) that present a breakdown of SNMP Agent statistics. Each statistic is presented as a percentage of overall traffic and as a total amount since the device was initialized. Packet Breakdown (Pie Chart) Received The total number of SNMP messages received by the device from the transport service. These statistics are displayed in yellow. Transmitted The total number of SNMP messages passed by the device to the transport service. These statistics are displayed in orange. SNMP Agent Detail View Errors The total number of SNMP messages received containing errors. These statistics are displayed in red. Discarded These statistics are displayed in gray and represent the total number of SNMP messages discarded. For example, messages between manager and agent that contain different version numbers are discarded. Error Breakdown ASN Parse Errs The total number of Abstract Syntax Notation One (ASN.1) or Basic Encoding Rules (BER) errors found by the device when decoding received SNMP messages. Too Big The total number of SNMP Protocol Data Units (PDUs) received or generated by the device in which the results of an operation could not fit into a single SNMP message. No Such Name The total number of SNMP PDUs received or generated by the device in which the requested operation identified an unknown variable name. Device Management Page 7 MIB-II Applications

8 SNMP Application Bad Values The total number of SNMP PDUs received or generated by the device in which the requested operation specified an incorrect syntax or value when attempting to modify a variable. Gen Errs The total number of SNMP PDUs received or generated by the device which contained types of errors other than those listed previously. Discard Breakdown (Pie Chart) Bad Versions The total number of SNMP messages with an unsupported version of SNMP which were received by the device. Bad Comm Name The community name (an OCTET STRING type) authenticates the manager before allowing access to the agent. If the value given by the manager does not match the agent s stored value then the SNMP message is marked as a bad community name. This number or statistic represents the total number of SNMP messages received that contained community names not recognized by the device. Auth Traps More SNMP Agent Detail View Bad Comm Uses The total number of SNMP messages received by the device that required an SNMP operation not allowed by the SNMP community named in the message. Clicking this button directs the SNMP Agent to generate authentication-failure traps. The value of this object overrides any configuration information; as such, it provides a means whereby all authentication-failure traps may be disabled. Possible states are Enabled and Disabled. If a difference exists between the manager and agent community name values, the agent sends an authentication failure trap message to the manager. Otherwise the SNMP PDU begins processing. Click on this button to open the SNMP Agent Detail 2 View. Device Management Page 8 MIB-II Applications

9 SNMP Application SNMP Agent Detail 2 View Access: From the Icon Subviews menu for the SNMP2_Agent Application icon, select Detail2, or click on the More button in the SNMP Agent Detail View. This view provides two color-coded pie charts (Receive and Transmit Breakdown) that present a breakdown of SNMP Agent statistics. Each statistic is presented as a percentage of overall traffic and as a total amount since the device was initialized. Receive Breakdown (Pie Chart) Get Requests The total number of SNMP Get-Request PDUs that have been accepted and processed by the device. Get-Request PDUs are used to retrieve the value of one or more objects from an agent. If the values do not match, the agent returns a GetResponse PDU with an Error Status dependent on what values did not match, as follows: Error Status - nosuchname, if a variable does not exactly match an available object. Error Status - nosuchname, if a variable is an aggregate type, e.g., a row object. SNMP Agent Detail 2 View Error Status - toobig, if the size of the appropriate GetResponse PDU exceeds a local limitation. Error Status - generr, if the value of a requested variable cannot be retrieved for any other reason. Get Nexts The total number of SNMP Get-Next PDUs that have been accepted and processed by the device. The manager uses the GetNextRequest PDU to retrieve one or more objects and their values from an agent. The difference between GetNextRequest and GetRequest is that GetNextRequest retrieves the value of the next object within the Agent s MIB View. There are three possible error conditions: Error Status - nosuchname, if a variable does not lexicographically precede the name of an object that may be retrieved. This condition is called running off the end of the MIB View. Error Status - toobig, if the size of the GetResponse exceeds a local limitation. Error Status - generr, if the value of the lexicographical successor to a requested variable cannot be retrieved for some other reason. Device Management Page 9 MIB-II Applications

10 SNMP Application Set Requests The total number of SNMP Set-Request PDUs that have been accepted and processed by the device. The SetRequest function assigns a value to an object residing in the agent. When the agent receives the SetRequest PDU, it alters the values of the named objects to the value in the variable binding. Four error conditions are possible: Error Status - nosuchname, if a variable is not available for a Set operation. Error Status - badvalue, if the value of a variable does not conform to the ASN.1 Type, Length, and Value required. Error Status - toobig, if the size of the GetResponse PDU exceeds a local limitation. Error Status - generr, if the value of the variable cannot be altered for any other reason. Transmit Breakdown Get Responses The total number of SNMP Get-Response PDUs that have been accepted and processed by the device. Out Traps The total number of SNMP Trap PDUs that have been accepted and processed by the device. The SNMP Agent Detail 2 View Trap PDU has a format distinct from the four other SNM PDUs. The Enterprise field identifies the management enterprise under whose registration authority the trap was defined. For example, the OID prefix { } identifies Network General Corp. as the Enterprise sending a trap. The seven types of traps that are reported from this variable are: coldstart - The sending protocol entity, higher layer network management, has reinitialized, indicating that neither the agent s configuration nor entity implementation may be altered. warmstart - The sending protocol has re- initialized, but neither the agent s configuration or protocol entity implementation has been altered. linkdown - A communication link has failed. linkup - A communication link has come up. authenticationfailure - The agent has received an improperly authenticated SNMP message from the manager; the community name was incorrect. egpneighborloss - An EGP peer neighbor is down. Device Management Page 10 MIB-II Applications

11 enterprisespecific - A nongeneric trap has occurred. Device Management Page 11 MIB-II Applications

12 IP Applications This section describes the Internet Protocols, collectively known as the IP Application. These protocols are used to communicate across any set of interconnected networks. The IP applications are equally suited for both local-area networks (LANs) and wide-area networks (WANs). This section describes the views available from the IP application. Internet Protocol (IP), the workhorse of the TCP/IP protocol suite, is commonly used as a delivery service. IP is a connectionless service responsible for moving datagrams from one device to another. As a delivery agent, IP watches to insure that the datagrams are within shipping regulations. To deliver datagrams, IP deals with two issues: addressing and fragmentation. Fragmentation may be necessary because the sequence of LANs and WANs that any particular datagram may traverse may have differing frame sizes, limitations, and the IP datagram must fit within these varying frame requirements. If a datagram is too large, IP repackages it into deliverable pieces using the fragmentation process. It then delivers the newly created pieces as individual datagrams and reassembles the fragments back into a single datagram at the distant node. The Internet Protocol (IP) group is mandatory for all managed nodes and provides information on host and router use of the IP. This group includes a number of objects that provide IP-related datagram statistics, including the following three tables: an address table, an IP-to-Physical Address Translation Table, and an IP Forwarding Table. (RFC 1354 defines the IP Forwarding Table, which replaces and makes obsolete the IP Routing Table in MIB-II.) Note: If the device you are modeling supports MIB-I attributes, you will see the IP_App. If the device supports MIB-II attributes, you will see the IP2_App. The applications are similar; this section will use the IP2_App as an example. Device Management Page 12 MIB-II Applications

13 IP Applications IP Application Views The following application-specific subviews may be accessed from the IP2_App Icon Subviews menu: IP Configuration View (Page 13) IP Routing View (Page 13) IP Routing Detail View (Page 15) IP Address Table (Page 16) IP Fragmentation View (Page 17) IP Reassembly View (Page 17) IP Net-To-Media Table View (Page 18) IP Configuration View Access: From the IP Routing Icon Subviews menu, select IP Configuration. This view provides configuration information for the router s IP process. For detailed information on the configuration view, see the section in your management module documentation titled Configuration Views. IP Routing View IP Application Views Access: From the IP Routing Icon Subviews menu, select IP Routing. This view provides route information. Destination Addr The destination IP address of this route. An entry value of is considered a default route. Multiple routes to a single destination can appear in the table, but access to such multiple entries is dependent on the table-access mechanisms defined by the network management protocol in use. Next Hop Addr The IP address of the next hop of this route. (In case of a route bound to an interface which is realized via a broadcast media, the value of this field is the agent s IP address on that interface. Interface The index value which uniquely identifies the local interface through which the next hop of this route should be reached. Route Age The number of seconds since this route was last updated or otherwise determined to be correct. Note that no semantics of too old can be implied Device Management Page 13 MIB-II Applications

14 IP Applications except through knowledge of the routing protocol by which the route was learned. Primary Metric The primary routing metric for this route. If this metric is not used, its value should be set to -1. Alt Metric 2 An alternate routing metric for this route. If this metric is not used, its value should be set to -1. Route Mask Indicates the mask to be associated with the destination address before being compared to the value in the IP Route Destination field. For those systems that do not support arbitrary subnet masks, an agent constructs the value of the IP Route Mask by determining whether the value of the correspondent IP Route Destination field belong to a class-a, B, or C network, and then using one of the following in Table 2: IP Routing View If the value of the IP Route Destination is (default route), then the mask value is also It should be noted that all IP routing subsystems implicitly use this mechanism. Metric 5 An alternate routing metric for this route. If this metric is not used, its value should be set to -1. Route Info A reference to MIB definitions specific to the particular routing protcol which is responsible for this route, as determined by the value specified in the route s IP Route Protocol 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 conformant implementation of ASN.1 and BER must be able to generate and recognize this value. mask Table 2: Route Mask network class-a class-b class-c Device Management Page 14 MIB-II Applications

15 IP Applications IP Routing Detail View Access: From the IP Routing Icon Subviews menu, select Detail. This views displays a detail view with three pie charts, showing statistical information in pie chart format. See Table 3, Packet Breakdown (Page 15), Table 4, Error Breakdown (Page 15), and Table 5, Discard Breakdown (Page 15). Statistic Table 3: Packet Breakdown Definition Statistic Header Address Table 4: IP Routing Detail View Error Breakdown Definition The total number of received datagrams discarded due to errors in their headers (e.g., time to live exceeded, version number mismatch, bad checksum, etc.) The total number of received datagrams discarded due to invalid addresses in the destination field. Delivered Forwarded Transmitted Errors Discarded The total number of packets delivered to a higher level protocol. The total number of packets forwarded. The total number of messages transmitted. The total number of messages received containing errors. The total number of messages discarded. Statistic No Routes Unknown Table 5: Discard Breakdown Definition The total number of datagrams discarded because no route could be found to transmit them to their destination address. The total number of locally addressed datagrams received successfully but discarded because of an unknown or unsupported protocol. Device Management Page 15 MIB-II Applications

16 IP Applications Table 5: Statistic In Discards (or In Discarded) Out Discards (or Out Discarded) Reassembly Fragmentation Discard Breakdown (Continued) Definition The total number of received datagrams discarded even though no errors were encountered to prevent their continued processing; such datagrams may have been discarded to increase buffer space. The total number of transmitted datagrams discarded even though no errors were encountered to prevent their continued processing; such datagrams may have been discarded to increase buffer space. The total number of datagram fragment reassembly failures detected by the reassembly algorithm due to time out, errors, etc. The total number of datagrams that could not be fragmented by the hub because their Don t Fragment flag was set. IP Address Table IP Address Table Access: From the IP Routing Icon Subviews menu, select IP Address Table. This table provides a description of each interface on the device. Double-click any field to access the IP Address Table view, used to add or change fields in the table. IP Address The network address of the interface. Interface The identification number of the interface. Net Mask Addr The subnet mask or MAC address of the interface. Broadcast Addr The broadcast address of the interface. Largest IP Datagram The largest IP datagram of the interface. Device Management Page 16 MIB-II Applications

17 IP Applications IP Fragmentation View Access: From the IP Routing Icon Subviews menu, select IP Fragmentation. The IP Fragmentation view displays any current fragmentation, and the degree of fragmentation. The IP Fragmentation view provides you with the pie chart information shown in Table 6. Table 6: Statistic Creates OKs Fails IP Fragmentation Breakdown Definition Number of IP datagram fragments generated as a result of fragmentation. Number of IP datagrams successfully fragmented. Number of IP datagrams discarded due to fragmentation. The Don t Fragment flag has already been set. IP Reassembly View IP Fragmentation View Access: From the Icon Subviews menu for the IP2_App Application icon, select Reassembly. The IP Reassembly view provides a pie chart, as shown in Table 7, with information on IP fragmentation and reassembly. One other view field is described below. IP Reassembly Timeout The maximum number of seconds which received fragments are held while they are awaiting reassembly at this entity. Table 7: Statistic Requests OKs Fails IP Reassembly Breakdown Definition The number of IP fragments received which needed to be reassembled at this entity. The number of IP datagrams successfully reassembled. The number of failures detected by the IP reassembly algorithm (for example, timed out, errors, etc.) Device Management Page 17 MIB-II Applications

18 IP Applications IP Net-To-Media Table View Access: From the Icon Subviews menu for the IP2_App Application icon, select IPNetToMedia Table. The IP Net-To-Media table allows you to view the ARP cache, which stores in memory the MAClayer addresses associated with the IP addresses of those hosts that are transmitting ARP traffic on each directly connected network segment. The form and function of the IP Net-To-Media table is defined by RFC The IP Net-To-Media table provides a report of all MAC-layer addresses that are associated with the IP hosts transmitting ARP packets on the connected network segment. This information is helpful when troubleshooting connectivity problems. IP Net-To-Media Table View Physical Address The physical, or MAC, address for this interface. Media Type Possible media types are: Dynamic, Static, Invalid, or Other. IP Net to Media Table Access: From the Icon Subviews menu for the IP2_App Application icon, select IPNetToMedia Table. Interface The IP network interface in the Media table. Network Address The known address that SPECTRUM uses to map the interface to the Media table. Device Management Page 18 MIB-II Applications

19 ICMP Application ICMP, created primarily as a means of reporting routing failures back to the source, performs a number of tasks within an IP internetwork. This section describes the views available from the ICMP application. Internet Control Message Protocol (ICMP) is part of the Network layer in the OSI (Open system Interconnection) model and an integral part of IP. Using the delivery services of IP, ICMP provides low-level feedback about how the network is operating. This protocol provides a number of basic control messages for reporting errors that may occur in the processing of datagrams, such as undeliverable datagrams or incorrect routes. ICMP is also used to test the path to a distant host via PING (packet internet groper), or to request an address mask for a particular subnet. The standard for ICMP is RFC 792. ICMP works to alleviate: Datagrams routed to the wrong destination (the redirect ICMP message) Excessive delays (time exceeded) The need for retransmissions (which consist of an information request and/or reply). Network managers need to understand each of these ICMP messages because they contain valuable information about network status. ICMP Detail View One application-specific subview is available for the ICMP application from the ICMP2_App Icon Subviews menu, the ICMP Detail View. For information on Performance and Detail views, refer to SPECTRUM Views..ICMP Application Detail View Access: From the Icon Subviews menu for the ICMP_App Application icon, select Detail, or click on the Detail button in the ICMP Performance View. This view provides three color-coded pie charts presenting a breakdown of ICMP application statistics. Each statistic is presented as a percentage of overall traffic and as a total amount Device Management Page 19 MIB-II Applications

20 since the device was initialized. Note that colors are used to denote a statistic in the graphs. Packet Breakdown (Pie Chart) Received The total number of ICMP messages received, including error messages. Designated by the color yellow. Transmitted The total number of ICMP messages transmitted, including error messages. Designated by the color orange. Errors The total number of ICMP messages received containing ICMP-specific errors (e.g., bad ICMP checksums, bad length, etc.). Designated by the color red. Discarded The total number of ICMP messages discarded. Designated by the color gray. Error Breakdown (Pie Chart) In Errors The total number of ICMP messages containing errors that the device received. Designated by the color red. Out Errors The total number of ICMP messages that the device did not transmit because of problems (e.g., lack of buffers). Designated by the color orange. InTime Exceed The total number of ICMP Time Exceeded messages received by the device. This indicates that an IP datagram was discarded because its TTL had expired or it was in the reassembly queue for too long. Designated by the color gray. Discard Breakdown (Pie Chart) OutTime Exceed The total number of ICMP Time Exceeded messages transmitted by the device. This indicates that an IP datagram was discarded because its TTL had expired or it was in the reassembly queue for too long. Designated by the color dark blue. In Unreach The total number of ICMP Destination Unreachable messages received by the device. This indicates that a network or host was unreachable, a protocol was not running, or IP datagram fragmentation was necessary but disallowed because the Don t Fragment flag was set. Designated by the color white. Device Management Page 20 MIB-II Applications

21 ICMP Application ICMP Detail View Out Unreach The total number of ICMP Destination Unreachable messages transmitted by the device. This indicates that a network or host was unreachable, a protocol was not running, or IP datagram fragmentation was necessary but disallowed because the Don t Fragment flag was set. Designated by the color light blue. Device Management Page 21 MIB-II Applications

22 TCP Application TCP, or Transmission Control Protocol, refers to the connection-oriented transport (communications) protocol used in the Internet suite. This section provides access and general information for the TCP views. The TCP application records parameters and statistics, such as the number of TCP segments transmitted. The protocol completes connection establishment, data transfer, and connection release phases. Each TCP entity maintains a Transmission Control Block (TCB) in order to track each connection. TCP is best described as being a finite state machine, which is initiated in the CLOSED state. As events occur, the TCP entity performs an action and enters a new state. TCP Views This section describes the views available for the TCP application. There are three applicationspecific subviews available from the TCP2_App Icon Subviews menu, and are described below: TCP Application Configuration View (Page 22) TCP Connection Table View (Page 23) TCP Detail View (Page 24) Note: If the device you are modeling supports MIB-I attributes, you will see the TCP_App. If the device supports MIB-II attributes, you will see the TCP2_App. The applications are similar; this section will use the TCP2_App as an example. TCP Application Configuration View Access: From the Icon Subviews menu for the TCP2_App, select Configuration. The TCP Application Configuration View provides detailed information about the TCP s configuration. Device Management Page 22 MIB-II Applications

23 Active Opens The total number of times TCP internet socket connections have made a direct transition from the CLOSED state to the SYN/SENT (synchronize/sent) state. Passive Opens The total number of times TCP internet socket connections have made a direct transition from the LISTEN state to the SYN/SENT (synchronize/sent) state. Attempt Fails The total number of times TCP internet socket connections have attempted and failed to make a direct transition from the SYN/SENT or SYN/RCVD state to the CLOSED state, plus the number of times TCP internet socket connections have made a direct transition from the SYN/RCVD state to the LISTEN state. Timeout Algo The algorithm used to determine the timeout value for retransmitting unacknowledged octets. Retrans Min The minimum value, in milliseconds, for the retransmission timeout. Retrans Max The maximum value, in milliseconds, for the retransmission timeout. Max Connection The total number of TCP connections the device can support. If the maximum number of TCP connections is dynamic, this field contains a value of -1. Establish Reset The number of times TCP connections have made a direct transition to the CLOSED state from either the ESTABLISHED state or the CLOSE-WAIT state. Current Estb The number of TCP connections for which the current state is either ESTABLISHED or CLOSE- WAIT. Segments Retrans The number of TCP segments retransmitted. This value indicates the number of TCP segments transmitted which contain one or more previously transmitted octets. TCP Connection Table View Access: From the Icon Subviews menu for the TCP2_App, select TCP Connection Table. The TCP Connection table view provides information about the device s current TCP internet socket connections. This table is dynamically updated as the connections change. Device Management Page 23 MIB-II Applications

24 TCP Application Connect State The state of this TCP connection. Local Address The local IP address for this TCP connection. In the case of a connection in the listen state which is willing to accept connections for any IP interface associated with the node, the value is used. Local Port The local port number for this TCP connection. Remote Address The remote IP address for this TCP connection. Remote Port The remote port number for this TCP connection. TCP Detail View Access: From the Icon Subviews menu for the TCP2_App, select Detail. This view provides color-coded pie charts (Packet and Error Breakdown) presenting a breakdown of TCP application statistics. Note that colors are used to denote a statistic in the multi-attribute line graph and pie charts. Packet Breakdown (Pie Chart) TCP Views Received The total number of TCP segments received including those containing errors. Transmitted The total number of TCP segments transmitted, excluding those containing only retransmitted octets. Errors TCP segments received containing errors. Error Breakdown (Pie Chart) Received The number of TCP segments received containing errors (e.g., bad TCP checksum). Device Management Page 24 MIB-II Applications

25 System Application This section describes the view available for the System Application. The System Application provides information on the network management subsystem, and network-related services offered by this device. Note: If the device you are modeling supports MIB-I attributes, you will see the System_App. If the device supports MIB-II attributes, you will see the System2_App. The applications are similar; this section will use the System2_App as an example. There is one application-specific view available for the System application: the System Configuration View (Page 25). System Configuration View Access: From the Icon Subviews menu for the System2_App icon, select Configuration. Name An administratively assigned name for the device. Object ID The Structure of Management Information (SMI) identification of the network management subsystem contained in the device. Descriptor A textual description of the device. This description includes the name and version of the hardware type, the software operating system, and the networking software. Services A series of read-only indicator buttons showing services offered by this device (physical, datalink, internet, transport, session, presentation, and application.) Device Management Page 25 MIB-II Applications

26 UDP Application This section describes the views available for the UDP application. User Datagram Protocol (UDP) is part of the transport layer of the OSI model and uses the services of IP to do its job of delivering data. UDP is a simpler protocol than TCP and is useful in situations where TCP s reliability for delivering data is not necessary. It provides for data transfer between devices using what is referred to as the connectionless mode and allows packets to be sent with a minimum of protocol overhead. However, this method does not guarantee delivery. Also, UDP does not compile information on connection attempts and no acknowledgments are sent. The only error checking provided by this protocol is by means of the checksum field. A checksum is an arithmetic sum used to verify data integrity. With UDP, the checksum value is calculated by a receiving station and, if that value does not agree with the checksum contained in the datagram being sent, the receiving system discards the incoming user datagram. UDP Views The application-specific subviews available for the UDP application from the UDP2_App Icon Subviews menu are: UDP Listener Table View (Page 26) UDP Performance View (Page 27) UDP Detail View (Page 27) UDP Listener Table View Access: From the Icon Subviews menu of the UDP2_App application icon, select UDP Listener. The UDP Listener Table provides information on the IP address and port number of the device s UDP endpoints on which a local application is currently accepting UDP datagrams. Double-click on a column entry to access a UDP Listener Interface Information View, in which you can modify the table entries. Device Management Page 26 MIB-II Applications

27 UDP Local Address The local IP address for this UDP listener. If this UDP listener is allowed to accept datagrams for any IP address associated with the node, the value used is UDP Local Port The local port number for this UDP listener. UDP Performance View Access: From the Icon Subviews menu for the UDP2_App application icon, select Performance. The UDP Performance View is identical to the MIB-II Performance View described earlier in this section. Detail Click on this button to display the UDP Detail View, which is described under UDP Detail View (Page 27). UDP Detail View Access: From the Icon Subviews menu for the UDP2_App application icon, select Detail, or click on the Detail button in the UDP Performance View. The UDP Detail View provides a color-coded pie chart presenting a breakdown of UDP application statistics. Received The total number of UDP datagrams delivered to UDP users. Denoted by the color yellow. Transmitted The total number of UDP datagrams sent from this entity. Denoted by the color orange. In Errors The number of UDP datagrams received containing errors. Denoted by the color red. No Ports The total number of UDP datagrams received for which there was no application at the destination port. Denoted by the color gray. Device Management Page 27 MIB-II Applications

28 30 Index A Abstract Syntax Notation One (ASN.1) 6 abstract syntaxes 6 Active Opens 23 Application view Download Application 15 ASN Parse Errs 7 ASN.1 6 Attempt Fails 23 authenticationfailure 10 B Bad Comm Name 8 Bad Versions 8 C coldstart 10 Connect State 24 Connection Table View 23 Current Estb 23 D Download Application 15 E egpneighborloss 10 Enterprise field 10 enterprisespecific 11 Establish Reset 23 F finite state machine 22 G GetNextRequest PDU 9 I ICMP Views 19 Detail 19 Internet Control Message Protocol 19 L linkdown 10 linkup 10 M Max Connection 23 MIB-II Performance View 6 MIB-II SNMP Application 6 MIB-II SNMP views 6 N No Such Name 7 O Open System Interconnection 6 OSI (Open System Interconnection) 6 Device Management Page 28 MIB-II Applications

29 Index Index P Passive Opens 23 PING 19 Protocol Data Units (PDUs) 6 R Retrans Max 23 Retrans Min 23 Transmission Control Block (TCB) 22 Transmission Control Protocol 22 transport service 7 W warmstart 10 S Segments Retrans 23 sending protocol entity 10 Set Requests 10 SNMP Agent Detail 2 View 9 SNMP Agent Detail View 7 SNMP Get-Request PDUs 9 SNMP Trap PDUs 10 SYN/SENT (synchronize/sent) 23 T TCP application 22 TCP Configuration View 22 TCP Detail View 24 TCP Views 22 Timeout Algo 23 Device Management Page 29 MIB-II Applications

30 Index Index Device Management Page 30 MIB-II Applications