All MIBs › OPENBSD-CARP-MIB
Organization: OpenBSD
Last Updated: 2012-01-31
Category: Operating Systems
Description:
Monitors CARP (Common Address Redundancy Protocol) group state and failover events on OpenBSD hosts.
Imported Objects
From OPENBSD-BASE-MIB
| openBSD | MODULE-IDENTITY |
From SNMPv2-CONF
| MODULE-COMPLIANCE | |
| OBJECT-GROUP |
From SNMPv2-SMI
| Counter64 | |
| Integer32 | |
| MODULE-IDENTITY | |
| NOTIFICATION-TYPE | |
| OBJECT-TYPE | |
| enterprises |
From SNMPv2-TC
| TruthValue |
What Is OPENBSD-CARP-MIB?
OPENBSD-CARP-MIB is a vendor-neutral MIB (originating from the OpenBSD project) for monitoring CARP (Common Address Redundancy Protocol) interfaces, which provide IP-address failover redundancy similar to VRRP. It exposes global CARP settings (carpAllow, carpPreempt, carpLog) alongside a per-interface table (carpIfTable/carpIfEntry) describing each CARP interface's virtual host ID, underlying device, advertisement base interval, and advertisement skew, plus a carpStats subtree. Its monitoring focus is software/protocol status: whether CARP is enabled, whether preemption is active, and the per-interface configuration and state that determines failover behavior, useful for confirming which host currently holds the master role for a virtual IP. It is a standalone protocol MIB not formally layered on other IETF MIBs, though it parallels VRRP-MIB concepts. It is deployed on OpenBSD-based firewalls and routers using CARP for high-availability failover. Engineers can download the OPENBSD-CARP-MIB file directly to load it into their MIB browser.
IPNetwork Monitor allows you to monitor SNMP objects defined in OPENBSD-CARP-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.
What Can Be Monitored
- CARP interface virtual host ID (VHID)
- CARP advertisement base interval and skew
- CARP preemption and logging settings
- per-interface CARP device binding
- CARP statistics
Supported Devices
- vendor-neutral, standards-based MIB, not tied to a specific manufacturer
- OpenBSD-based firewalls and routers using CARP
Monitoring Examples
An administrator would poll carpIfTable/carpIfEntry, keyed by carpIfIndex, to read carpIfVhid, carpIfDev, carpIfAdvbase, and carpIfAdvskew for each CARP interface and confirm the advertisement timing is configured as expected across a redundant pair. Checking carpIfDescr alongside carpStats would reveal whether a host has unexpectedly transitioned roles, which combined with carpPreempt and carpLog settings would explain an unplanned failover event. A mismatch in carpIfAdvskew between the two peers could explain flapping between master and backup states.
OIDs
| OID symbolic | OID numeric | Type | Access | Description |
|---|---|---|---|---|
| carpMIBObjects | 1.3.6.1.4.1.30155.6 | The MIB module for gathering information about Common Address Redundancy Protocol (CARP) interfaces. | ||
| carpSysctl | 1.3.6.1.4.1.30155.6.1 | |||
| T/F carpAllow | 1.3.6.1.4.1.30155.6.1.1 | TruthValue | read-only | Indicates whether the node will respond to CARP packets. |
| T/F carpPreempt | 1.3.6.1.4.1.30155.6.1.2 | TruthValue | read-only | Indicates whether preemption is enabled. |
| T/F carpLog | 1.3.6.1.4.1.30155.6.1.3 | TruthValue | read-only | Indicates whether logging of invalid CARP packets is enabled. |
| carpIf | 1.3.6.1.4.1.30155.6.2 | |||
| I32 carpIfNumber | 1.3.6.1.4.1.30155.6.2.1 | Integer32 | read-only | The number of CARP interfaces present on this system. |
| carpIfTable | 1.3.6.1.4.1.30155.6.2.2 | not-accessible | A list of individual CARP interfaces. The number of entries is given by the value of carpIfNumber. | |
| carpIfEntry | 1.3.6.1.4.1.30155.6.2.2.1 | not-accessible | An entry containing management information applicable to a particular CARP interface. | |
| I32 carpIfIndex | 1.3.6.1.4.1.30155.6.2.2.1.1 | Integer32 | read-only | A unique value, greater than zero, for each CARP interface. |
| OCT carpIfDescr | 1.3.6.1.4.1.30155.6.2.2.1.2 | OCTET STRING | read-only | The name of the CARP interface. |
| I32 carpIfVhid | 1.3.6.1.4.1.30155.6.2.2.1.3 | Integer32 | read-only | The Virtual HostID of the CARP interface. |
| OCT carpIfDev | 1.3.6.1.4.1.30155.6.2.2.1.4 | OCTET STRING | read-only | The parent interface that the CARP interface is bound to. |
| I32 carpIfAdvbase | 1.3.6.1.4.1.30155.6.2.2.1.5 | Integer32 | read-only | The advbase value of the CARP interface. |
| I32 carpIfAdvskew | 1.3.6.1.4.1.30155.6.2.2.1.6 | Integer32 | read-only | The advskew value of the CARP interface. |
| INT carpIfState | 1.3.6.1.4.1.30155.6.2.2.1.7 | INTEGER | read-only | Indicates the operational state of the CARP interface. |
| carpStats | 1.3.6.1.4.1.30155.6.3 | |||
| C64 carpIpPktsRecv | 1.3.6.1.4.1.30155.6.3.1 | Counter64 | read-only | Number of IPv4 CARP packets received on all interfaces. |
| C64 carpIp6PktsRecv | 1.3.6.1.4.1.30155.6.3.2 | Counter64 | read-only | Number of IPv6 CARP packets received on all interfaces. |
| C64 carpPktDiscardsForBadInterface | 1.3.6.1.4.1.30155.6.3.3 | Counter64 | read-only | Number of packets discarded due to being received on a non-CARP interface. |
| C64 carpPktDiscardsForWrongTtl | 1.3.6.1.4.1.30155.6.3.4 | Counter64 | read-only | Number of packets discarded due to having a TTL less than 255. |
| C64 carpPktShorterThanHeader | 1.3.6.1.4.1.30155.6.3.5 | Counter64 | read-only | Number of packets received on any interface that is shorter than the size of the CARP packet header. |
| C64 carpPktDiscardsForBadChecksum | 1.3.6.1.4.1.30155.6.3.6 | Counter64 | read-only | Number of packets discarded due to bad checksum. |
| C64 carpPktDiscardsForBadVersion | 1.3.6.1.4.1.30155.6.3.7 | Counter64 | read-only | Number of packets discarded due to bad version in the packet header. |
| C64 carpPktDiscardsForTooShort | 1.3.6.1.4.1.30155.6.3.8 | Counter64 | read-only | Number of packets discarded due to being too short. |
| C64 carpPktDiscardsForBadAuth | 1.3.6.1.4.1.30155.6.3.9 | Counter64 | read-only | Number of packets discarded because they failed the HMAC authentication check. |
| C64 carpPktDiscardsForBadVhid | 1.3.6.1.4.1.30155.6.3.10 | Counter64 | read-only | Number of packets discarded due to incorrect VHID in the packet header. |
| C64 carpPktDiscardsForBadAddressList | 1.3.6.1.4.1.30155.6.3.11 | Counter64 | read-only | Number of packets discarded due to bad addresses in the CARP packet. |
| C64 carpIpPktsSent | 1.3.6.1.4.1.30155.6.3.12 | Counter64 | read-only | Number of IPv4 CARP packets sent on all interfaces. |
| C64 carpIp6PktsSent | 1.3.6.1.4.1.30155.6.3.13 | Counter64 | read-only | Number of IPv6 CARP packets sent on all interfaces. |
| C64 carpNoMemory | 1.3.6.1.4.1.30155.6.3.14 | Counter64 | read-only | Number of CARP advertisements that failed because memory could not be allocated. |
| C64 carpTransitionsToMaster | 1.3.6.1.4.1.30155.6.3.15 | Counter64 | read-only | Number of times the host has transitioned to MASTER state for any CARP group. |
RFC description
Monitors Common Address Redundancy Protocol (CARP) interfaces and failover status on OpenBSD systems.
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