All MIBs › JUNIPER-JS-SCREENING-MIB › jnxJsScreenMonTcpNoFlag
jnxJsScreenMonTcpNoFlag
Module: JUNIPER-JS-SCREENING-MIB
OID (symbolic): JUNIPER-JS-SCREENING-MIB::jnxJsScreenMonTcpNoFlag
OID (numeric): 1.3.6.1.4.1.2636.3.39.1.8.1.1.1.1.15
Node type: OBJECT-TYPE
Type: Counter64
Access: read-only
Description: A normal TCP segment header has at least one flag control set. A TCP segment with no control flags set is an anomalous event. Operating systems respond to such anomalies in different ways. The response, or even lack of response, from the targeted device can provide a clue as to the target's OS type.
When this option is enabled, if the device discovers such a header with a missing or malformed flags field, it drops the packet.
The attribure records the detection of TCP without flag set packets.
What is jnxJsScreenMonTcpNoFlag?
This read-only counter tallies TCP packets caught in this zone with no control flags set at all, an anomalous header some attackers craft to fingerprint a target OS by its response. An admin watching this counter climb knows probing traffic exploiting non-standard TCP headers is being blocked.
Examples
Walk all instances (SNMPv2c):
snmpwalk -v2c -c public <target> 1.3.6.1.4.1.2636.3.39.1.8.1.1.1.1.15 snmpwalk -v2c -c public <target> JUNIPER-JS-SCREENING-MIB::jnxJsScreenMonTcpNoFlag
Get a specific instance (index 1):
snmpget -v2c -c public <target> 1.3.6.1.4.1.2636.3.39.1.8.1.1.1.1.15.1 snmpget -v2c -c public <target> JUNIPER-JS-SCREENING-MIB::jnxJsScreenMonTcpNoFlag.1
Start monitoring Juniper SRX/J-series security appliance (DoS/DDoS screen defenses) with a free 30-day trial of IPNetwork Monitor. Create custom SNMP monitor using the JUNIPER-JS-SCREENING-MIB::jnxJsScreenMonTcpNoFlag OID value, configure state conditions and alerts, and monitor any Juniper SRX/J-series security appliance (DoS/DDoS screen defenses) from a single console.
OID Breakdown
Upper-level ancestors (11 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 |
| 1.3.6.1.4 | private | AirPair-MIB |
| 1.3.6.1.4.1 | enterprises | AirPair-MIB |
| 1.3.6.1.4.1.2636 | juniperMIB | JUNIPER-SMI |
| 1.3.6.1.4.1.2636.3 | jnxMibs | JUNIPER-SMI |
| 1.3.6.1.4.1.2636.3.39 | jnxJsMibRoot | JUNIPER-SMI |
| 1.3.6.1.4.1.2636.3.39.1 | jnxJsSecurity | JUNIPER-JS-SMI |
| 1.3.6.1.4.1.2636.3.39.1.8 | jnxJsScreening | JUNIPER-JS-SMI |
| Numeric OID | Name | Module |
|---|---|---|
| 1.3.6.1.4.1.2636.3.39.1.8.1 | jnxJsScreenMIB | JUNIPER-JS-SCREENING-MIB |
| 1.3.6.1.4.1.2636.3.39.1.8.1.1 | jnxJsScreenObjects | JUNIPER-JS-SCREENING-MIB |
| 1.3.6.1.4.1.2636.3.39.1.8.1.1.1 | jnxJsScreenMonTable | JUNIPER-JS-SCREENING-MIB |
| 1.3.6.1.4.1.2636.3.39.1.8.1.1.1.1 | jnxJsScreenMonEntry | JUNIPER-JS-SCREENING-MIB |
| 1.3.6.1.4.1.2636.3.39.1.8.1.1.1.1.15 | jnxJsScreenMonTcpNoFlag | JUNIPER-JS-SCREENING-MIB |