BgpSessionMonitor

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

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.

A SNMP get request for BGP_PEER_STATE_OID returns a result between 1 to 6. The servicestates for OpenNMS HORIZON are mapped as follows:

Result State description Monitor state in OpenNMS HORIZON

1

Idle

DOWN

2

Connect

DOWN

3

Active

DOWN

4

OpenSent

DOWN

5

OpenConfirm

DOWN

6

Established

UP

Monitor facts

Class Name

org.opennms.netmgt.poller.monitors.BgpSessionMonitor

Remote Enabled

false

To define the mapping I used the description from RFC1771 BGP Finite State Machine.

Configuration and Usage
Parameter Description Required Default value

bgpPeerIp

IP address of the far end BGP peer session

required

-

retry

Amount of attempts to get the BGP peer state with SNMP

required

-

timeout

Time to wait for the SNMP agents response before trying a next attempt.

required

-

Examples

To monitor the session state Established it is necessary to 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. To make it human readable a codemapping table is implemented:

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

Instead of HEX-Code the error message will be displayed in the service down logmessage. To give some additional informations the logmessage contains also

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

If you have problems to detect or monitor the BGP Session you can use the following command to figure out where the problem come from.

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.