show interfaces (Multilink Services)

Physical interface

Name of the physical interface.

Enabled

State of the interface. Possible values are described in the “Enabled Field” section under Common Output Fields Description.

Interface index

Physical interface's index number, which reflects its initialization sequence.

SNMP ifIndex

SNMP index number for the physical interface.

Generation

Unique number for use by Juniper Networks technical support only.

Link-level type

Encapsulation being used on the physical interface: Multilink.

MTU

MTU size on the physical interface.

Device flags

Information about the physical device. Possible values are described in the “Device Flags” section under Common Output Fields Description.

Interface flags

Information about the interface. Possible values are described in the “Interface Flags” section under Common Output Fields Description.

Last flapped

Date, time, and how long ago the interface went from down to up. The format is Last flapped: year-month-day hour:minute:second timezone (hour:minute:second ago). For example, Last flapped: 2002-04-26 10:52:40 PDT (04:33:20 ago).

Statistics last cleared

Time when the statistics for the interface were last set to zero.

Traffic statistics

Number and rate of bytes and packets received and transmitted on the physical interface. All references to traffic direction (input or output) are defined with respect to the router. Input fragments received by the router are assembled into input packets; output packets are segmented into output fragments for transmission out of the router.

Frame exceptions

Information about framing exceptions. Includes events recorded under Exception Events for each logical interface:

• Oversized frames—Number of frames received that exceed maximum frame length. Maximum length is 4500 Kb (kilobits).

• Errored input frames—Number of input frame errors.

• Input on disabled link/bundle—Number of frames received on disabled links. These can result either from an inconsistent configuration, or from a bundle or link being brought up or down with traffic actively flowing through it.

• Output for disabled link/bundle—Number of frames sent for a disabled or unavailable link. These can result either from an inconsistent configuration, or from a bundle being brought up or down with traffic actively flowing through it.

• Queuing drops—Total number of packets dropped before traffic enters the link services IQ interface. Indicates that the interface is becoming oversubscribed.

Buffering exceptions

Information about buffering exceptions. Includes events recorded under Exception Events for each logical interface:

• Packet data buffer overflow—Packet buffer memory is full. This overflow can occur when the aggregate data rate exceeds the physical multilink services interface capacity.

• Fragment data buffer overflow—Fragment buffer memory is full. This overflow can occur when excessive differential delay is experienced across the links within a single bundle, or when the aggregate data rate exceeds the physical multilink services interface capacity. Check the logical interface exception event counters to determine which bundle is responsible.

Assembly exceptions

Information about assembly exceptions. Includes events recorded under Exception Events for each logical interface.

An assembly exception does not necessarily indicate an operational problem with the Multilink PIC itself. If multilink-encapsulated traffic is dropped or reordered after a sequence number has been assigned, the assembling multilink interface records one or more exception events. The multilink interface can drop multilink-encapsulated fragments itself as a result. Any multilink packets or fragments dropped by the Multilink PIC itself result in packet or fragment drop counts on individual logical interfaces. If the logical interface drop counts are zero, but exception events are seen, the most likely cause is a problem with the individual link interfaces. Even if the logical interface fragment drop counts are nonzero, excess differential delay or traffic losses on individual interfaces can be the root cause.

• Fragment timeout—Drop-timer expired while a fragment sequence number was outstanding. Occurs only if drop-timer is enabled. This can occur if the differential delay across the links in a bundle exceeds the drop-timer setting, or if a multilink packet is lost in transit while the drop timer is enabled. These events do not necessarily indicate any problem with the operation of the Multilink PIC itself. If one or more individual links drop traffic, these events can occur. Check the logical interface exception event counters to determine which bundle is responsible.

• Missing sequence number—A gap was detected in the sequence numbers of fragments on a bundle. These events do not necessarily indicate any problem with the operation of the Multilink PIC itself. If one or more individual links drop traffic, these events can occur. Check the logical interface exception event counters to determine which bundle is responsible.

• Out-of-order sequence number—Two frames with out-of-order sequence numbers occurred within a single link. This event indicates that an individual link within a bundle reordered traffic, making the multilink interface unable to correctly process the resulting stream. Check the logical interface exception event counters to determine which bundle is responsible.

• Out-of-range sequence number—Frame was received with out-of-range sequence number. These events can occur when a large amount of multilink-encapsulated traffic is lost, or the multilink peer is reset, so that a large jump in sequence numbers results. A small number of these events can occur when the far end of a bundle is taken down or brought up. Check the logical interface exception event counters to determine which bundle is responsible.

Hardware errors

Information about hardware errors:

• Data memory error—A memory error was detected on the interface DRAM. Indicates possible hardware failure. Contact Juniper Networks technical support.

• Control memory error—A memory error was detected on the interface DRAM. Indicates possible hardware failure. Contact Juniper Networks technical support.

Logical interface

Logical interface name.

Index

Logical interface index number, which reflects its initialization sequence.

SNMP ifIndex

SNMP interface index number.

Encapsulation

Encapsulation being used: PPP or Multilink PPP.

Bandwidth

Speed at which the interface is running.

Flags

Logical interface flags. Possible values are described in the “Logical Interface Flags” section under Common Output Fields Description.

Bundle options

Information about configured bundle options:

• MRRU—Configured size of the MRRU (maximum received reconstructed unit). It can be 1500 to 4500 bytes.

• Drop timer period—Configured drop timeout period. It can be 0 through 127 ms. A value of 0 disables the timer. The default setting is 0.

• Sequence number format—Configured size of the sequence header: 12 or 24 bits. The default is 24 bits.

• Fragmentation threshold—Configured fragmentation threshold. A value of 0 results in no fragmentation. Nonzero values can be 128 through 16,320 bytes, in integer multiples of 64 bytes. The default is 0.

• Links needed to sustain bundle—Minimum number of links to sustain the bundle: 1 through 8.

Bundle status (MLPPP) or Multilink class status (MC-MLPPP)

Information about bundle status:

• Remote MRRU—MRRU value received from remote peer. If negotiation has not been initiated, the default value is displayed.

• Received sequence number—Sequence number for received packets.

• Transmitted sequence number—Sequence number for transmitted packets.

• Packet drops—Number and byte count of output packets that were dropped, rather than being encapsulated and sent out of the router as fragments. The packet drop counter is incremented if there is a temporary shortage of packet memory on the AS PIC, which causes packet fragmentation to fail.

• Fragment drops—Number and byte count of input fragments that were dropped, rather than being reassembled and handled by the router as packets. This counter also includes fragments that have been received successfully but had to be dropped because not all fragments that constituted a packet had been received. The fragment drop counter is incremented when a fragment received on constituent links is dropped. Drop fragments can be triggered by sequence ordering errors, duplicate fragments, timed-out fragments, and bad multilink headers.

• MRRU exceeded—Number of reassembled packets exceeding the MRRU. This counter is not implemented in this release.

• Fragment timeout—Drop timer expired while a fragment sequence number was outstanding. Occurs only if the drop timer is enabled. This timeout can occur if the differential delay across the links in a bundle exceeds the drop-timer setting, or if a multilink packet is lost in transit while the drop timer is enabled.

• Missing sequence number—Gap detected in the sequence numbers of fragments on a bundle.

• Out-of-order sequence number—Two frames with out-of-order sequence numbers within a single link. This event indicates that an individual link within a bundle reordered traffic, making the multilink interface unable to correctly process the resulting stream.

• Out-of-range sequence number—Frame with an out-of-range sequence number. These events can occur when a large amount of multilink-encapsulated traffic is lost or the multilink peer is reset, so that a large jump in sequence numbers results. A small number of these events can occur when the far end of a bundle is taken down or brought up.

• Packet data buffer overflow—Packet buffer memory full. This overflow can occur when the aggregate data rate exceeds the physical link services IQ interface capacity.

• Fragment data buffer overflow—Fragment buffer memory full. This overflow can occur when excessive differential delay is experienced across the links within a single bundle, or when the aggregate data rate exceeds the physical link services IQ capacity.

Remote MRRU

MRRU value received from remote peer. If negotiation has not been initiated, the default value is displayed.

Bundle errors

Information about bundle errors:

• Packet drops—Number and byte count of output packets dropped, rather than being encapsulated and sent out of the router as fragments.

• Fragment drops—Number and byte count of input fragments dropped, rather than being reassembled and handled by the router as packets.

• MRRU exceeded—Number of reassembled packets exceeding the MRRU.

• Exception events—Number of exceptional events encountered while handling traffic on the bundle, other than MRRU exceeded errors. These events are categorized under the physical interface: Frame exceptions, Buffering exceptions, and Fragment exceptions. Exception events do not necessarily indicate that the multilink interface is not operating properly. Individual link failures can produce exceptional events.

Statistics

Information about fragments and packets received and sent by the router. All references to traffic direction (input or output) are defined with respect to the router. Input fragments received by the router are assembled into input packets; output packets are segmented into output fragments for transmission out of the router.

• Bundle—Information about bundles.

• Link—Information about links used in the multilink operation.

Protocol

Protocol family configured on the logical interface.

MTU

MTU size on the logical interface. If the MTU value is negotiated down to meet the MRRU requirement on the remote side, this value is marked Adjusted.

Flags

Information about the protocol family flags. Possible values are described in the “Family Flags” section under Common Output Fields Description.

Generation

Unique number for use by Juniper Networks technical support only.

Route table

Route table in which this address exists. For example, Route table:0 refers to inet.0.

Addresses, Flags

Information about the address flags. Possible values are described in the “Addresses Flags” section under Common Output Fields Description.

Destination

IP address of the remote side of the connection.

Local

IP address of the logical interface.

Broadcast

Broadcast address on the logical interface.

Generation

Unique number for use by Juniper Networks technical support only.