BgpSessionMonitor

This monitor checks if a BGP session to a peering partner (peer-ip) is functional. The monitor uses the RFC1269 SNMP MIB to monitor the BGP-Session, and uses the following OIDs to test the session status:

BGP_PEER_STATE_OID = .1.3.6.1.2.1.15.3.1.2.<peer-ip>
BGP_PEER_ADMIN_STATE_OID = .1.3.6.1.2.1.15.3.1.3.<peer-ip>
BGP_PEER_REMOTEAS_OID = .1.3.6.1.2.1.15.3.1.9.<peer-ip>
BGP_PEER_LAST_ERROR_OID = .1.3.6.1.2.1.15.3.1.14.<peer-ip>
BGP_PEER_FSM_EST_TIME_OID = .1.3.6.1.2.1.15.3.1.16.<peer-ip>

The <peer-ip> is the far end IP address of the BGP session end point.

An SNMP GET request for BGP_PEER_STATE_OID returns a result between 1 and 6. The service states for Horizon are mapped as follows:

Result	State description	Monitor state in Horizon
1	Idle	DOWN
2	Connect	DOWN
3	Active	DOWN
4	OpenSent	DOWN
5	OpenConfirm	DOWN
6	Established	UP

Result

State description

Monitor state in Horizon

Idle

DOWN

Connect

DOWN

Active

DOWN

OpenSent

DOWN

OpenConfirm

DOWN

Established

Monitor facts

Class Name

org.opennms.netmgt.poller.monitors.BgpSessionMonitor

See RFC1771 BGP Finite State Machine for more information on how we defined the mapping.

Configuration and use

Table 1. Required monitor-specific parameter for the BgpSessionMonitor
Parameter	Description	Default
bgpPeerIp	IP address of the far end BGP peer session	n/a
bgpBaseOid	Default base OID for the table that represents the BGP sessions.	.1.3.6.1.2.1.15
bgpPeerStateOid	OID suffix for the table that represents the BGP-peer states.	bgpBaseOid.3.1.2
bgpPeerAdminStateOid	OID suffix for the table that represents the BGP-peer admin states.	bgpBaseOid.3.1.3
bgpPeerRemoteAsOid	OID suffix for the table that represents the BGP-peer remote AS number.	bgpBaseOid.3.1.9
bgpPeerLastErrorOid	OID suffix for the table that represents the BGP-peer last error code.	bgpBaseOid.3.1.14
bgpPeerFsmEstTimeOid	OID suffix for the table that represents the BGP-peer established time.	bgpBaseOid.3.1.16

This monitor implements the Common Configuration Parameters.

Examples

To monitor the session state Established, add a service to your poller configuration in $OPENNMS_HOME/etc/poller-configuration.xml. For example:

<!-- Example configuration poller-configuration.xml -->
<service name="BGP-Peer-99.99.99.99-AS65423" interval="300000"
         user-defined="false" status="on">
    <parameter key="retry" value="2" />
    <parameter key="timeout" value="3000" />
    <parameter key="port" value="161" />
    <parameter key="bgpPeerIp" value="99.99.99.99" />
</service>

<monitor service="BGP-Peer-99.99.99.99-AS65423" class-name="org.opennms.netmgt.poller.monitors.BgpSessionMonitor" />

Error code mapping

The BGP_PEER_LAST_ERROR_OID gives an error in hex code. The error codes returned are listed in the table below.

Error code	Error Message
0100	Message Header Error
0101	Message Header Error - Connection Not Synchronized
0102	Message Header Error - Bad Message Length
0103	Message Header Error - Bad Message Type
0200	OPEN Message Error
0201	OPEN Message Error - Unsupported Version Number
0202	OPEN Message Error - Bad Peer AS
0203	OPEN Message Error - Bad BGP Identifier
0204	OPEN Message Error - Unsupported Optional Parameter
0205	OPEN Message Error (deprecated)
0206	OPEN Message Error - Unacceptable Hold Time
0300	UPDATE Message Error
0301	UPDATE Message Error - Malformed Attribute List
0302	UPDATE Message Error - Unrecognized Well-known Attribute
0303	UPDATE Message Error - Missing Well-known Attribute
0304	UPDATE Message Error - Attribute Flags Error
0305	UPDATE Message Error - Attribute Length Error
0306	UPDATE Message Error - Invalid ORIGIN Attribute
0307	UPDATE Message Error (deprecated)
0308	UPDATE Message Error - Invalid NEXT_HOP Attribute
0309	UPDATE Message Error - Optional Attribute Error
030A	UPDATE Message Error - Invalid Network Field
030B	UPDATE Message Error - Malformed AS_PATH
0400	Hold Timer Expired
0500	Finite State Machine Error
0600	Cease
0601	Cease - Maximum Number of Prefixes Reached
0602	Cease - Administrative Shutdown
0603	Cease - Peer De-configured
0604	Cease - Administrative Reset
0605	Cease - Connection Rejected
0606	Cease - Other Configuration Change
0607	Cease - Connection Collision Resolution
0608	Cease - Out of Resources

The error message text will be displayed in the service down log message. The log message also provides the following additional information:

BGP-Peer Adminstate
BGP-Peer Remote AS
BGP-Peer established time in seconds

Debugging

If you cannot detect or monitor the BGP session, use the following command to check that the device is providing BGP data via SNMP.

snmpwalk -v 2c -c <myCommunity> <myRouter2Monitor> .1.3.6.1.2.1.15.3.1.2.99.99.99.99

Replace 99.99.99.99 with your BGP-Peer IP. The result should be an integer between 1 and 6.