SLED-MIB :: sledLoopbackEnable

MIB Reference — IPNetwork Monitor · Updated October 06, 2026

All MIBs › SLED-MIB › sledLoopbackEnable

sledLoopbackEnable

Module: SLED-MIB

OID (symbolic): SLED-MIB::sledLoopbackEnable

OID (numeric): 1.3.6.1.4.1.4491.2.1.13.1.2.2

Node type: OBJECT-TYPE

Type: TruthValue

Access: read-write

Description: Setting this object to 'true' enables the loopback function. Setting this object to 'false' disables the loopback function. When enabled, the eCM removes the Ethernet FCS/CRC32 from the original packets. All Ethernet packets received by the SLED from the LCI are then processed as follows:

1. If the received Ethernet packet is greater than 1472 octets, the Ethernet packet is split into two fragments, the first consisting of the first 1472 octets of the Ethernet packet and the second containing the remaining octets, resulting in two payloads that are processed as described below. If the received Ethernet packet is less than or equal to 1472 octets, the entire packet will be processed as a single payload. 2. For each payload generated in step 1, the payload is appended to the contents of sledLoopbackPktHdr. 3. The mutable fields within sledLoopbackPktHdr MUST be recomputed. The mutable fields are IP Header Checksum, IP Total Length, UDP Checksum, and UDP Length. 4. If the Ethernet packet was fragmented in step 1, the appropriate IP header fields (Flags and Fragment Offset) are updated to indicate IP fragmentation These IP fragmentation header values will differ depending on if this is the first or second fragment being processed. 5. The Ethernet FCS is computed and appended. 6. The resulting Ethernet packet is transmitted to the LCI.

What is sledLoopbackEnable?

Setting this object to true enables the SLED Ethernet loopback function, which strips FCS/CRC32, fragments oversized packets, appends the header from sledLoopbackPktHdr, recomputes IP/UDP checksums and lengths, and retransmits the packet back out the LCI; setting it to false disables the loopback. Admins use it to run remote diagnostic loopback tests over the cable plant to verify CPE-side connectivity end-to-end. For example, enabling sledLoopbackEnable during a truck-roll-avoidance diagnostic lets a technician confirm packets reach and return from a customer's modem without visiting the site.

Examples

Walk all instances (SNMPv2c):

snmpwalk -v2c -c public <target> 1.3.6.1.4.1.4491.2.1.13.1.2.2
snmpwalk -v2c -c public <target> SLED-MIB::sledLoopbackEnable

Get a specific instance (index 1):

snmpget -v2c -c public <target> 1.3.6.1.4.1.4491.2.1.13.1.2.2.1
snmpget -v2c -c public <target> SLED-MIB::sledLoopbackEnable.1

Set instance 1 (SNMPv2c):

snmpset -v2c -c private <target> 1.3.6.1.4.1.4491.2.1.13.1.2.2.1 s <value>

Start monitoring eDOCSIS-embedded cable device, e.g. cable modem/eMTA with embedded application (loopback diagnostic test config) with a free 30-day trial of IPNetwork Monitor. Create custom SNMP monitor using the SLED-MIB::sledLoopbackEnable OID value, configure state conditions and alerts, and monitor any eDOCSIS-embedded cable device, e.g. cable modem/eMTA with embedded application (loopback diagnostic test config) from a single console.

OID Breakdown

Upper-level ancestors (10 from the standard OID tree / other modules)
Numeric OIDNameModule
1isoLANART-AGENT
1.3orgAirPair-MIB
1.3.6dodAirPair-MIB
1.3.6.1internetAirPair-MIB
1.3.6.1.4privateAirPair-MIB
1.3.6.1.4.1enterprisesAirPair-MIB
1.3.6.1.4.1.4491cableLabsCLAB-DEF-MIB
1.3.6.1.4.1.4491.2clabProjectCLAB-DEF-MIB
1.3.6.1.4.1.4491.2.1clabProjDocsisCLAB-DEF-MIB
1.3.6.1.4.1.4491.2.1.13sledMibCLAB-DEF-MIB
Numeric OIDNameModule
1.3.6.1.4.1.4491.2.1.13.1sledMibObjectsSLED-MIB
1.3.6.1.4.1.4491.2.1.13.1.2sledLoopbackSLED-MIB
1.3.6.1.4.1.4491.2.1.13.1.2.2sledLoopbackEnableSLED-MIB