TUNNEL-MIB

MIB Reference — IPNetwork Monitor · Updated September 09, 2026

All MIBsTUNNEL-MIB

Organization: IETF IP Version 6 (IPv6) Working Group

Last Updated: 2005-05-16

Category: IP and Core Protocols

Description: Defines managed objects for managing IP tunnels of any type (GRE, IP-in-IP, L2TP, PPTP, and others) over IPv4 and IPv6 networks.

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

What Is TUNNEL-MIB?

TUNNEL-MIB is a vendor-neutral IETF standards MIB (RFC 4087) that defines managed objects for configuring and monitoring IP tunnel interfaces independent of the specific encapsulation scheme, covering technologies like GRE, IP-in-IP, L2TP, and PPTP over both IPv4 and IPv6. It exposes a tunnel interface table describing each tunnel's local and remote endpoint addresses, encapsulation method, hop limit, security mode, type-of-service, and IPv6 flow label, effectively giving a configuration and topology view of every active tunnel on a device via the TUNNEL-MIB OID list defined in RFC 4087. For hardware/software status monitoring, this MIB's role is primarily to confirm tunnel interfaces are correctly configured and operationally consistent (e.g., matching local/remote addressing and encapsulation), and combined with IF-MIB counters it can reveal a tunnel that is administratively up but not passing traffic. It has an explicit dependency on IF-MIB, since each tunnel is represented as an ifEntry and this MIB's tunnelIfTable is indexed by ifIndex to supply tunnel-specific attributes. It is typically deployed on routers and VPN/tunnel-terminating devices that support multiple tunneling protocols and need a unified, encapsulation-agnostic management view.

IPNetwork Monitor allows you to monitor SNMP objects defined in TUNNEL-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

  • vendor-neutral, standards-based MIB, not tied to a specific manufacturer
  • router or VPN gateway supporting IP tunneling (GRE, IP-in-IP, L2TP, PPTP)

Monitoring Examples

An administrator would poll tunnelIfTable/tunnelIfEntry, checking tunnelIfLocalAddress and tunnelIfRemoteAddress against expected endpoint pairs, and tunnelIfEncapsMethod to confirm the correct protocol (e.g., GRE vs IP-in-IP) is in use for a given tunnel interface. Monitoring tunnelIfHopLimit and tunnelIfTOS/tunnelIfFlowLabel alongside IF-MIB's ifOperStatus for the same ifIndex would reveal a tunnel whose encapsulation settings mismatch the peer, a common cause of a tunnel showing up but silently dropping packets. Using tunnelIfAddressType with tunnelIfLocalInetAddress/tunnelIfRemoteInetAddress lets the same table represent IPv6 tunnels alongside IPv4 ones.

What Can Be Monitored

  • tunnel local and remote endpoint addresses
  • tunnel encapsulation method
  • tunnel hop limit and TOS/flow label settings
  • tunnel interface operational status (via IF-MIB)
  • IPv4/IPv6 tunnel address type
Imported Objects

From IANAifType-MIB

IANAtunnelType

From IF-MIB

InterfaceIndexOrZero
ifIndexOBJECT-TYPE

From INET-ADDRESS-MIB

InetAddress
InetAddressType

From IPV6-FLOW-LABEL-MIB

IPv6FlowLabelOrAny

From SNMPv2-CONF

MODULE-COMPLIANCE
OBJECT-GROUP

From SNMPv2-SMI

Integer32
IpAddress
MODULE-IDENTITY
OBJECT-TYPE
transmission

From SNMPv2-TC

RowStatus
StorageType
OIDs

FAQ

How can TUNNEL-MIB help confirm a GRE tunnel is configured consistently on both ends?
Its tunnel interface table reports each tunnel's local and remote endpoint addresses along with the encapsulation method, hop limit, and TOS/flow label settings, so comparing these values against the far-end configuration quickly reveals endpoint or encapsulation mismatches.

Why would a tunnel show as up in TUNNEL-MIB but still not be passing traffic?
TUNNEL-MIB mainly confirms configuration and topology consistency; since each tunnel is represented as an ifEntry indexed by ifIndex, you need to cross-reference IF-MIB counters on that same index to see whether the tunnel is administratively up but not actually forwarding packets.

RFC description

IETF MIB for management of IP tunnels independent of encapsulation scheme (RFC 4087).

Start monitoring vendor-neutral, standards-based MIB, router or VPN gateway supporting IP tunneling (GRE/IP-in-IP/L2TP/PPTP admin/oper status) with a free 30-day trial of IPNetwork Monitor. Import MIBs, browse SNMP OIDs, create custom SNMP monitors, configure alerts, and monitor any SNMP-enabled network device from a single console.

Download TUNNEL-MIB