JUNIPER-L2ALD-MIB

All MIBs › JUNIPER-L2ALD-MIB

Organization: Juniper Networks, Inc.

Last Updated: 2015--0-1-

Category: Technology: Bridging, Technology: Switching/L2, Vendor: Juniper

Description: Defines managed objects for Layer 2 Address Learning Daemon (L2ALD) operations on Juniper Networks EX switches, including MAC table statistics.

Start monitoring vendor-neutral, standards-based MIB, any SNMPv3-capable network device (SNMP engine identity/boot/clock 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.

What Is JUNIPER-L2ALD-MIB?

JUNIPER-L2ALD-MIB defines managed objects and traps for the Layer 2 Address Learning Daemon (L2ALD) on Juniper EX-series switches, the software process responsible for learning and aging MAC addresses in the switch's forwarding table. It exposes global feature-enable settings, a notification interval, counters of MAC addresses learned and removed, and a history table logging each MAC learning/removal event with a timestamp. This is a software-process and network-state monitoring MIB: administrators use it to confirm the L2ALD daemon is healthy and actively tracking MAC learning activity, and to detect abnormal churn that could indicate a MAC-flapping loop or unauthorized device activity. It closely parallels (and likely shares lineage with) JUNIPER-EX-MAC-NOTIFICATION-MIB, both building on the standard bridge forwarding-database concept from BRIDGE-MIB. Typical deployment is Juniper EX-series access/aggregation switches where Layer 2 forwarding-table stability needs to be monitored. Engineers can download the JUNIPER-L2ALD-MIB file directly to load it into their MIB browser.

IPNetwork Monitor allows you to monitor SNMP objects defined in JUNIPER-L2ALD-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

Juniper EX-series Ethernet switch

Monitoring Examples

An administrator would monitor jnxL2aldMacAddressesLearnt and jnxL2aldMacAddressesRemoved for unusual churn, then drill into jnxL2aldMacHistoryTable/jnxL2aldMacHistoryEntry (via jnxL2aldHistIndex, jnxL2aldHistMacChangedMsg, jnxL2aldHistTimestamp) to pinpoint which MAC addresses changed and when, which would reveal a spanning-tree loop or a rogue device causing rapid relearning. jnxL2aldMacNotificationsSent confirms traps are firing as configured via jnxL2aldMacNotificationInterval, and jnxL2aldMacHistTableMaxLength governs how much history is retained for post-incident analysis.

What Can Be Monitored

MAC addresses learned/removed counts
L2ALD MAC history log
notification interval and enable state
notifications sent count
forwarding-table churn events

Imported Objects

From IF-MIB

ifDescr	OBJECT-TYPE
ifIndex	OBJECT-TYPE

From JUNIPER-SMI

jnxl2aldMibRoot

OBJECT-IDENTITY

From SNMPv2-SMI

Counter64
Integer32
MODULE-IDENTITY
NOTIFICATION-TYPE
OBJECT-IDENTITY
OBJECT-TYPE
TimeTicks
Unsigned32

From SNMPv2-TC

DisplayString
TruthValue

How to Use in IPNetwork Monitor

Example using jnxL2aldMacAddressesLearnt OID:

Select a Juniper EX-series Ethernet switch (L2ALD MAC learning daemon) as the target host to create a monitor — the SNMP service should be up and running on it. Click New Monitor, then check SNMP Custom on the Favorites tab, click Next, and confirm the host. On the next page, click Select... to open the built-in SNMP MIB Browser and type jnxL2aldMacAddressesLearnt into the Find box to locate it in the OID tree, then select it and click OK. Indicates the number of MAC addresses learnt by the device. On the monitor's Main parameters page you can set the target's SNMP port (default 161), credentials, polling interval, and other settings — see the SNMP Monitor help for details. On the State conditions and Alerting tabs, configure when the monitor should change state and trigger an alert; since this is a Counter64-type OID, Value bounds is the most useful condition here — trigger an alert if the counter increases sharply between polls relative to its normal baseline, since an unexpected spike often reflects a real change in traffic or activity. Click Finish to create the monitor; you can adjust any parameter later.

OIDs

OID symbolic	OID numeric	Type	Access	Description
jnxl2aldMib	1.3.6.1.4.1.2636.3.48.1			The MIB modules for L2ALD traps
jnxl2aldNotification	1.3.6.1.4.1.2636.3.48.1.0
NTF jnxl2aldRoutingInstMacLimit	1.3.6.1.4.1.2636.3.48.1.0.1			This notification is generated when the MAC limit for given routing instance (jnxl2aldRoutingInst) is reached. This trap is send only once we exceed the limit value.
NTF jnxl2aldInterfaceMacLimit	1.3.6.1.4.1.2636.3.48.1.0.2			This notification is generated when the MAC limit for the given physical interface (jnxl2aldInterfaceMacLimit) is reached. This trap is send only once we exceed the limit value.
NTF jnxl2aldGlobalMacLimit	1.3.6.1.4.1.2636.3.48.1.0.3			This notification is generated when the MAC limit for the entire system is reached. This trap is send only once we exceed the limit value.
NTF jnxl2aldMacMoveThreshold	1.3.6.1.4.1.2636.3.48.1.0.4			This notification is generated when a mac move reaches threshold. The given interface (ifDescr) will be blocked for the Bridge Domain(jnxl2aldIntfBridgeDomain). This trap is send only once when mac move count exceeds the threshold for the Mac(jnxl2aldMacAdress).
NTF jnxL2aldMacChangedNotification	1.3.6.1.4.1.2636.3.48.1.0.5			This notification is generated when there is enough MAC address information to fully occupy a maximum size SNMP trap message. This notification is also generated when there is at least one MAC address changed or removed and the amount of time elapsed from the previous notification is greater than the maximum wait time denoted by jnxNotificationInterval object. If there are more MAC addresses information than can fit into one cmmHistTrapContent object, then multiple notifications will be generated.
jnxl2aldObjects	1.3.6.1.4.1.2636.3.48.1.1
jnxl2aldInterfaceTable	1.3.6.1.4.1.2636.3.48.1.1.1		not-accessible	L2ALD objects for interface MAC limit.
jnxl2aldEntry	1.3.6.1.4.1.2636.3.48.1.1.1.1		not-accessible	An entry in l2aldInterfaceTable.
STR jnxl2aldIntfLogicalRouter	1.3.6.1.4.1.2636.3.48.1.1.1.1.1	DisplayString	accessible-for-notify	The logical router string for interface table.
STR jnxl2aldIntfRoutingInst	1.3.6.1.4.1.2636.3.48.1.1.1.1.2	DisplayString	accessible-for-notify	The routing instance string for interface table.
STR jnxl2aldIntfBridgeDomain	1.3.6.1.4.1.2636.3.48.1.1.1.1.3	DisplayString	accessible-for-notify	The bridge domain string for interface table.
U32 jnxl2aldIntfMacLimit	1.3.6.1.4.1.2636.3.48.1.1.1.1.4	Unsigned32	accessible-for-notify	The MAC limit count for the interface table.
STR jnxl2aldRoutingInst	1.3.6.1.4.1.2636.3.48.1.1.2	DisplayString	accessible-for-notify	The Routing instance string for routing mac limit trap.
STR jnxl2aldBridgeDomain	1.3.6.1.4.1.2636.3.48.1.1.3	DisplayString	accessible-for-notify	The bridge domain string for routing mac limit trap.
STR jnxl2aldLogicalRouter	1.3.6.1.4.1.2636.3.48.1.1.4	DisplayString	accessible-for-notify	The logical router string for routing mac limit trap.
U32 jnxl2aldMacLimit	1.3.6.1.4.1.2636.3.48.1.1.5	Unsigned32	accessible-for-notify	The mac limit count for routing instance.
U32 jnxl2aldGbMacLimit	1.3.6.1.4.1.2636.3.48.1.1.6	Unsigned32	accessible-for-notify	The mac limit count for the system.
STR jnxl2aldMacAdress	1.3.6.1.4.1.2636.3.48.1.1.7	DisplayString	accessible-for-notify	The offending mac causing mac move threshold trap.
jnxL2aldMacNotificationMIBObjects	1.3.6.1.4.1.2636.3.48.1.2
jnxL2aldMacNotificationMIBGlobalObjects	1.3.6.1.4.1.2636.3.48.1.2.1
T/F jnxL2aldMacGlobalFeatureEnabled	1.3.6.1.4.1.2636.3.48.1.2.1.1	TruthValue	read-only	Indicates whether the MAC notification feature is currently running in the device. Setting this object to false(2) disables the MAC notification feature globally. Setting this object to true(1) will start the MAC notification feature running in the device. If the feature is already running, setting to true(1) has no effect.
U32 jnxL2aldMacNotificationInterval	1.3.6.1.4.1.2636.3.48.1.2.1.2	Unsigned32	read-only	This object specifies the maximum interval of time between jnxL2aldMacChangedNotifications being generated by the device. If the value of jnxNotificationsEnabled is true(1), the device will send out the generated jnxL2aldMacChangedNotifications and archive the MAC change notification events in the jnxMacHistoryTable. If the value of jnxNotificationEnabled is false(2), the device will not send out the generated jnxL2aldMacChangedNotifications but it will archive these events in the jnxMacHistoryTable. If the value of this object is equal to 0, the device will generate jnxL2aldMacChangedNotifications and archive the MAC change notification events in the jnxMacHistoryTable as soon as there is MAC address learnt or removed by the device. If the value of this object is greater than 0, the device will wait for a period of time equal to the value of this object before generate the jnxL2aldMacChangedNotifications and archive the MAC change notification events in the jnxMacHistoryTable.
C64 jnxL2aldMacAddressesLearntEx	1.3.6.1.4.1.2636.3.48.1.2.1.3	Counter64	read-only	Indicates the number of MAC addresses learnt by the device.
C64 jnxL2aldMacAddressesRemoved	1.3.6.1.4.1.2636.3.48.1.2.1.4	Counter64	read-only	Indicates the number of MAC addresses removed from the forwarding database.
T/F jnxL2aldMacNotificationsEnabled	1.3.6.1.4.1.2636.3.48.1.2.1.5	TruthValue	read-only	Indicates whether jnxL2aldMacChangedNotification notifications will or will not be sent when there are MAC addresses learnt or removed from the device's forwarding database. Disabling notifications does not prevent the MAC address info from being added to the jnxMacHistoryTable.
C64 jnxL2aldMacNotificationsSent	1.3.6.1.4.1.2636.3.48.1.2.1.6	Counter64	read-only	Indicates the number of jnxl2aldMacChangedNotifications sent out by the device.
U32 jnxL2aldMacHistTableMaxLength	1.3.6.1.4.1.2636.3.48.1.2.1.7	Unsigned32	read-only	The upper limit on the number of entries that the jnxMacHistoryTable may contain. A value of 0 will prevent any history from being retained. When this table is full, the oldest entry will be deleted and a new one will be created.
jnxL2aldMacHistoryTable	1.3.6.1.4.1.2636.3.48.1.2.1.8		not-accessible	This table will archive the MAC change notification events generated by this device. The MAC change notification events are archived here even if jnxMacChangesNotifications are not actually sent.
jnxL2aldMacHistoryEntry	1.3.6.1.4.1.2636.3.48.1.2.1.8.1		not-accessible	A MAC change notification message that was previously generated by this device. Each entry is indexed by a message index.
U32 jnxL2aldHistIndex	1.3.6.1.4.1.2636.3.48.1.2.1.8.1.1	Unsigned32	not-accessible	An index that uniquely identifies a MAC change notification event previously generated by the device. This index starts at 1 and increases by one when a MAC change notification is generated. When it reaches the maximum value, the agent wraps the value back to 1.
OCT jnxL2aldHistMacChangedMsg	1.3.6.1.4.1.2636.3.48.1.2.1.8.1.2	OCTET STRING	read-only	This object contains the information of a MAC change notification event. It consists of several tuples packed together in the format of '...'. Each tuple consist of 13 octets in the format of '' where is of size 1 octet and supports the following values 0 - End of MIB object. 1 - MAC learnt. 2 - MAC removed. 3 - MAC updated. is the index of the VLAN which the MAC address is belonged to and has size of 2 octet. is the Layer2 Mac Address and has size of 6 octets. is the value of dot1dBasePort for the interface from which the MAC address is learnt and has size of 2 octets. is the tag of the VLAN which the MAC address is belonged to and has size of 2 octet.
TIK jnxL2aldHistTimestamp	1.3.6.1.4.1.2636.3.48.1.2.1.8.1.3	TimeTicks	read-only	The value of sysUpTime when the jnxL2aldMacChangedNotification containing the information denoted by the jnxHistMacChangedMsg object in this entry was generated.
C64 jnxL2aldMacAddressesUpdated	1.3.6.1.4.1.2636.3.48.1.2.1.9	Counter64	read-only	Indicates the number of MAC addresses updated by the device.
jnxL2aldVlanMIBObjects	1.3.6.1.4.1.2636.3.48.1.3
jnxL2aldVlanTable	1.3.6.1.4.1.2636.3.48.1.3.1		not-accessible	A table of VLAN names and characteristics.
jnxL2aldVlanEntry	1.3.6.1.4.1.2636.3.48.1.3.1.1		not-accessible	A table entry containing VLAN names and characteristics.
I32 jnxL2aldVlanID	1.3.6.1.4.1.2636.3.48.1.3.1.1.1	Integer32	not-accessible	This is the locally significant ID that is used internally by this device to reference this VLAN.
STR jnxL2aldVlanName	1.3.6.1.4.1.2636.3.48.1.3.1.1.2	DisplayString	read-only	Vlan name is the textual name and this is the identifier that the user of a configuration utility will use.
I32 jnxL2aldVlanTag	1.3.6.1.4.1.2636.3.48.1.3.1.1.3	Integer32	read-only	This is the locally significant ID that is used internally by this device to reference this VLAN.
INT jnxL2aldVlanType	1.3.6.1.4.1.2636.3.48.1.3.1.1.4	INTEGER	read-only	The vlan type can be Static (1) Dynamic(2)
U32 jnxL2aldVlanFdbId	1.3.6.1.4.1.2636.3.48.1.3.1.1.5	Unsigned32	read-only	The identity of the Filtering Database dot1qFdbTable (A table that contains configuration and control information for each Filtering Database currently operating on this device)

RFC description

Juniper L2ALD (Layer 2 Address Learning Disable) MIB for MAC address limit traps and VLAN management.

Start monitoring Juniper EX-series Ethernet switch (L2ALD MAC learning daemon) 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 JUNIPER-L2ALD-MIB