# Connectivity (Node)

The Connectivity section summarizes each port's link status in a table. Each active port is followed by its neighboring port, and inactive ports are presented in gray. Data shown in the table are the port counters for each involved port and the table columns are configurable with the top-right corner button.

Note: If link speed and link width are displayed with red color, it indicates the following situations:

- Slow speed – active speed/width is lower than configured

- Configured slow speed – enabled speed is lower than supported

- Mismatched speed - active speed/width does not match neighboring port

Right-click on a port to open a menu to quickly jump to this port’s performance page or topology page.

Left-click on a Cable Info column to directly display cable information about this port.

The fields in the table below can be selected from the drop-down list at the upper-right corner of the section.

Connectivity Data
Option | Description
--- | ---
Node Name | Node Name is typically assigned by the system administrator based on the desired naming convention. It is typically the same or derived from the Linux hostname for the server. Once selected by the sysadmin, the value persists across OS reboot.
Node GUID | GUID of the HFI or Switch.
Port # | The link port number this SMP came on in.
Link State | Port State
Physical Link State | Physical Port State
LinkQualityIndicator | This is a status indicator, similar to the signal strength bar display on a mobile phone, that enumerates link quality as a range of 0-5, with 5 being very good. Values in the lower part of the range may indicate hardware problems such as port, cable, etc. that surface as signal integrity issues, leading to performance and other problems.
Link Width | The possible values for link width: 1x, 2x, 3x, 4x.
Link Width Enabled | The set of link widths that the LNI protocol negotiates. The LNI protocol uses only LW.E to negotiate link width during LNI.
Link Width Supported | The link widths the port can negotiate to during LNI. In some implementations firmware/driver and/or local device settings may restrict this value further.
Active Link Speed | The link speed active value of this port.
Link Speed Enabled | The link speed enabled value of this port.
Link Speed Supported | The link speed supported value of this port.
RcvData (MB) | Receive Data Rate in Megabytes per second (MBps).
RcvPkts | The total number of received fabric data packets.
MulticastRcvPkts | The total number of multicast and collective packets received. This counter includes all valid packets and all packets with a header up to and including the DLID, where the DLID is within the configured range for multicast or collectives. Packets within the configured multicast or collective address space are counted, even if later checks determine the packet is unroutable or exceeds the SwitchInfo.MulticastFDBCap, SwitchInfo.CollectiveFDBCap, configured SwitchInfo.MulticastFDBTop or configured SwitchInfo.CollectiveFDBTop.
RcvErrors | This counter indicates the total number of packets containing an error that were received by the port, including physical errors and malformed packets. It may indicate possible misconfiguration of a port, either by the SM or (more likely) by user intervention (e.g., using a tool such as opaportconfig).
RcvConstraintErrors | This counter is incremented when partition key or source LID violations are detected in a received packet, indicating a possible security issue or misconfiguration of device security settings.
RcvSwitchRelayErrors | This counter indicates the number of packets that were dropped due to internal routing errors. It is indicative of the possible misconfiguration of a switch by the SM.
RcvRemotePhysicalErrors | This counter indicates the number of downstream effects of signal integrity problems. It is indicative of an SI issue in the upstream path.
RcvFECN | When a device receives a packet with the FECN (Forward Explicit Congestion Notification) bit set to one, this counter is incremented.
RcvBECN | When a device receives a packet with the BECN (Backward Explicit Congestion Notification) bit set to one, this counter is incremented.
RcvBubble | This counter indicates the total number of "flit times" where one or more packets have started to be received, but the receiver received idle flits from the wire.
XmitData (MB) | The total number of transmitted fabric data in Megabytes.
XmitPkts | The total number of fabric packets transmitted. This counter includes all fabric packet head flits transmitted with and without errors (such as PktBadHead).
MulticastXmitPkts | The total number of multicast and collective packets transmitted
XmitDiscards | The number of packets dropped due to one of the following errors: Switch lifetime Limit exceeded Switch head-of-queue lifetime limit exceeded Output port not in active state Packet length exceeded maximum fabric packet size for MTU for VL Flow control disabled and insufficient credits available SC2VL_t mapping invalid for given SC
XmitConstrainErrors | This counter is incremented when partition key or source LID violations are detected in a packet attempting to be transmitted, indicating a possible security issue or misconfiguration of device security settings.
XmitWait | This counter indicates the amount of time (in "flit times") any virtual lane had data but was unable to transmit (for reasons such as no credits available, or that the link was busy sending non-data packets such as link layer retraining or flow control).
XmitTimeCong | This counter indicates the total number of "flit times" that the counter was in a congested state.
XmitWastedBW | This counter indicates the number of "flit times" where one or more packets have been started but the transmitters are forced to send idles due to bubbles.
XmitWaitData | This counter indicates the number of "flit times" where one or more packets have been started but interrupted due to bubbles in the ingress stream.
LocalLinkIntegrityErrors | This counter indicates the number of retries initiated by the link transfer layer. It may be indicative of low signal quality, or may be due to long or low quality cables.
FMConfigErrors | This counter indicates inconsistencies of low level SMA configuration on both sides of the link. It is indicative of the possible misconfiguration of a port, either by the SM, or (more likely) by user intervention (by using a tool such as `opaportconfig`).
ExcessiveBufferOverruns | This counter, associated with credit management, indicates an input buffer overrun. It may indicate possible misconfiguration of a port, either by the SM or (more likely) by user intervention (e.g., using a tool such as opaportconfig).
SwPortCongestion | This switch-only counter indicates the number of packets that were discarded as unable to transmit due to flow control issues.
MarkFECN | This counter indicates the total number of packets that were marked FECN by the transmitter due to congestion.
LinkErrorRecovery | This counter indicates the number of times the link has successfully completed the link error recovery process. If LQI is fluctuating toward low values AND this counter is increasing, it may be indicative of a bad link. Indication of a more severe signal quality problem.
LinkDowned | This counter indicates the total number of times the port has failed the link error recovery process and downed the link. A large number of occurrences of these events can cause disruptions to fabric traffic.
UncorrectableErrors | This counter indicates the number of unrecoverable internal device errors. It is indicative of a severe hardware defect or data corruption on the wire.