CISCO-TCP-MIB

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Organization: Cisco Systems, Inc.

Last Updated: 2001-11-12

Category: Cisco Devices, IP and Core Protocols

Description: Extends TCP connection management with Cisco-specific connection states, timer values, and performance counters.

IPNetwork Monitor uses several OIDs from this MIB in network discovery and polling the applicable devices. Start monitoring CISCO-TCP-MIB with a free 30-day trial of IPNetwork Monitor.

What Is CISCO-TCP-MIB?

CISCO-TCP-MIB is a Cisco enterprise extension to the standard IETF TCP-MIB, adding vendor-specific detail about individual TCP connections on Cisco routers and switches. It exposes per-connection performance and health data through the ciscoTcpConnTable, layered on top of the base TCP connection identification already defined by the standard MIB. This makes it directly useful for monitoring software-level networking health: byte and packet counters, retransmission counts, smoothed round-trip time (SRTT), retransmission timeout (RTO), and connection elapsed time all help detect degraded TCP sessions, congestion, or misbehaving applications on the device. As an explicit extension, it depends on and augments the IETF TCP-MIB (RFC 4022), reusing its connection indexing rather than duplicating it. It is typically deployed wherever operators need finer-grained TCP diagnostics than the standard MIB provides, such as troubleshooting slow or unreliable management-plane or application sessions on Cisco IOS/IOS XE/NX-OS devices. Engineers can download the CISCO-TCP-MIB file directly to load it into their MIB browser.

IPNetwork Monitor allows you to monitor SNMP objects defined in CISCO-TCP-MIB. Use the built-in SNMP Monitoring Browser to explore available variables, view their current values and descriptions, and select the objects you want to monitor. You can then create SNMP monitors, configure thresholds, and receive alerts when monitored values change.

Supported Devices

Cisco routers
Cisco switches
Cisco IOS/IOS XE/NX-OS devices

Monitoring Examples

An administrator can poll ciscoTcpConnTable/ciscoTcpConnEntry, keyed like the base tcpConnTable, to read ciscoTcpConnInBytes/ciscoTcpConnOutBytes and ciscoTcpConnInPkts/ciscoTcpConnOutPkts for throughput on a specific connection. A rising ciscoTcpConnRetransPkts or ciscoTcpConnFastRetransPkts count alongside a growing ciscoTcpConnSRTT and ciscoTcpConnRto would reveal a congested or lossy path affecting that TCP session. ciscoTcpConnElapsed helps distinguish a long-lived, stable session from one that is repeatedly reconnecting.

What Can Be Monitored

TCP connection inbound/outbound bytes
TCP connection inbound/outbound packets
retransmitted packet counts
fast retransmit counts
smoothed round-trip time (SRTT)
retransmission timeout (RTO) and connection elapsed time

Imported Objects

From CISCO-SMI

ciscoMgmt

OBJECT-IDENTITY

From SNMPv2-CONF

MODULE-COMPLIANCE
OBJECT-GROUP

From SNMPv2-SMI

Counter32
Integer32
MODULE-IDENTITY
OBJECT-TYPE
TimeTicks

From TCP-MIB

tcpConnEntry

OBJECT-TYPE

How to Use in IPNetwork Monitor

Example using ciscoTcpConnInBytes OID:

Select a Cisco IOS/IOS-XE/NX-OS router and switch (TCP) as the target host to create a monitor — the SNMP service should be up and running on it. Click New Monitor, then check SNMP Custom on the Favorites tab, click Next, and confirm the host. On the next page, click Select... to open the built-in SNMP MIB Browser and type ciscoTcpConnInBytes into the Find box to locate it in the OID tree, selecting the specific row/instance you want to monitor since this is a table column, then select it and click OK. It reports the number of bytes that have been input on this TCP connection. On the monitor's Main parameters page you can set the target's SNMP port (default 161), credentials, polling interval, and other settings — see the SNMP Monitor help for details. On the State conditions and Alerting tabs, configure when the monitor should change state and trigger an alert; since this is a Counter32-type OID, Value bounds is the most useful condition here — trigger an alert if the counter increases sharply between polls relative to its normal baseline, since an unexpected spike often reflects a real change in traffic or activity. Click Finish to create the monitor; you can adjust any parameter later.

OIDs

OID symbolic	OID numeric	Type	Access	Description
ciscoTcpMIB	1.3.6.1.4.1.9.9.6			An extension to the IETF MIB module for managing TCP implementations
ciscoTcpMIBObjects	1.3.6.1.4.1.9.9.6.1
ciscoTcpConnTable	1.3.6.1.4.1.9.9.6.1.1		not-accessible	A table containing TCP connection-specific information.
ciscoTcpConnEntry	1.3.6.1.4.1.9.9.6.1.1.1		not-accessible	Additional information about a particular current TCP connection beyond that provided by the TCP-MIB tcpConnEntry. An object of this type is transient, in that it ceases to exist when (or soon after) the connection makes the transition to the CLOSED state.
C32 ciscoTcpConnInBytesEx	1.3.6.1.4.1.9.9.6.1.1.1.1	Counter32	read-only	Number of bytes that have been input on this TCP connection.
C32 ciscoTcpConnOutBytes	1.3.6.1.4.1.9.9.6.1.1.1.2	Counter32	read-only	Number of bytes that have been output on this TCP connection.
C32 ciscoTcpConnInPkts	1.3.6.1.4.1.9.9.6.1.1.1.3	Counter32	read-only	Number of packets that have been input on this TCP connection.
C32 ciscoTcpConnOutPkts	1.3.6.1.4.1.9.9.6.1.1.1.4	Counter32	read-only	Number of packets that have been output on this TCP connection.
TIK ciscoTcpConnElapsed	1.3.6.1.4.1.9.9.6.1.1.1.5	TimeTicks	read-only	Amount of time this TCP connection has been established.
I32 ciscoTcpConnSRTT	1.3.6.1.4.1.9.9.6.1.1.1.6	Integer32	read-only	`Smoothed' round-trip time for this TCP connection.
C32 ciscoTcpConnRetransPkts	1.3.6.1.4.1.9.9.6.1.1.1.7	Counter32	read-only	The total number of packets retransmitted due to a timeout - that is, the number of TCP segments transmitted containing one or more previously transmitted octets.
C32 ciscoTcpConnFastRetransPkts	1.3.6.1.4.1.9.9.6.1.1.1.8	Counter32	read-only	The total number of packets retransmitted using an advanced algorithm such as Fast Retransmit or Selective Acknowledgement - that is, the number of TCP segments transmitted containing one or more previously transmitted octets.
I32 ciscoTcpConnRto	1.3.6.1.4.1.9.9.6.1.1.1.9	Integer32	read-only	The current value used by a TCP implementation for the retransmission timeout.
ciscoTcpMIBTraps	1.3.6.1.4.1.9.9.6.2
ciscoTcpMIBConformance	1.3.6.1.4.1.9.9.6.3
ciscoTcpMIBCompliances	1.3.6.1.4.1.9.9.6.3.1
ciscoTcpMIBCompliance	1.3.6.1.4.1.9.9.6.3.1.1			The compliance statement for entities which implement the Cisco TCP MIB
ciscoTcpMIBComplianceRev1	1.3.6.1.4.1.9.9.6.3.1.2			The compliance statement for entities which implement the Cisco TCP MIB
ciscoTcpMIBGroups	1.3.6.1.4.1.9.9.6.3.2
ciscoTcpMIBGroup	1.3.6.1.4.1.9.9.6.3.2.1			A collection of objects providing TCP connection monitoring.
ciscoTcpMIBGroupRev1	1.3.6.1.4.1.9.9.6.3.2.2			A collection of objects providing TCP connection monitoring.

RFC description

TCP connection statistics extension providing per-connection metrics like retransmission counts and round-trip time.

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Download CISCO-TCP-MIB