All MIBs › TCP-MIB › tcpConnectionState
tcpConnectionState
Module: TCP-MIB
OID (symbolic): TCP-MIB::tcpConnectionState
OID (numeric): 1.3.6.1.2.1.6.19.1.7
Node type: OBJECT-TYPE
Type: INTEGER
Access: read-write
Description: The state of this TCP connection.
The value listen(2) is included only for parallelism to the old tcpConnTable and should not be used. A connection in LISTEN state should be present in the tcpListenerTable.
The only value that may be set by a management station is deleteTCB(12). Accordingly, it is appropriate for an agent to return a `badValue' response if a management station attempts to set this object to any other value.
If a management station sets this object to the value deleteTCB(12), then the TCB (as defined in [RFC793]) of the corresponding connection on the managed node is deleted, resulting in immediate termination of the connection.
As an implementation-specific option, a RST segment may be sent from the managed node to the other TCP endpoint (note, however, that RST segments are not sent reliably).
What is tcpConnectionState?
This value reports and, for one specific case, controls the state of an individual TCP connection, using standard states like established(5), synSent(3), or timeWait(11); per the source, the only value a manager may write is deleteTCB(12), which immediately terminates that connection on the device. A network administrator uses this to both inspect which connections are open (e.g., troubleshooting a stuck session) and to forcibly kill a hung or malicious connection by writing deleteTCB(12) to it. For example, an admin who spots a connection stuck in closeWait(8) for hours could set its tcpConnectionState to deleteTCB(12) to clear it.
Examples
Walk all instances (SNMPv2c):
snmpwalk -v2c -c public <target> 1.3.6.1.2.1.6.19.1.7 snmpwalk -v2c -c public <target> TCP-MIB::tcpConnectionState
Get a specific instance (index 1):
snmpget -v2c -c public <target> 1.3.6.1.2.1.6.19.1.7.1 snmpget -v2c -c public <target> TCP-MIB::tcpConnectionState.1
Set instance 1 (SNMPv2c):
snmpset -v2c -c private <target> 1.3.6.1.2.1.6.19.1.7.1 i <value>
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OID Breakdown
Upper-level ancestors (7 from the standard OID tree / other modules)
| Numeric OID | Name | Module |
|---|---|---|
| 1 | iso | LANART-AGENT |
| 1.3 | org | AirPair-MIB |
| 1.3.6 | dod | AirPair-MIB |
| 1.3.6.1 | internet | AirPair-MIB |
| 1.3.6.1.2 | mgmt | AXON-MIB |
| 1.3.6.1.2.1 | mib_2 | AXON-MIB |
| 1.3.6.1.2.1.6 | tcp | CHECKPOINT-MIB-2 |
| Numeric OID | Name | Module |
|---|---|---|
| 1.3.6.1.2.1.6.19 | tcpConnectionTable | TCP-MIB |
| 1.3.6.1.2.1.6.19.1 | tcpConnectionEntry | TCP-MIB |
| 1.3.6.1.2.1.6.19.1.7 | tcpConnectionState | TCP-MIB |