NIC Subsystem

The Compaq NIC Management Agents display all logical Compaq Network Interface Controllers (NICs) that are configured on the system you are viewing. The following items can appear in the NIC section of the navigation frame:

Virtual NIC

Single NIC

Team of NICs

Virtual NIC

The Virtual NIC is the TCP/IP Loopback interface. It is provided by Operating System to allow a computer to send packets to itself. A packet is the fundamental unit of transmission on the physical network.

Select the Virtual NIC to view detailed Interface Information.

Single NIC

A single NIC is composed of one physical adapter. Select a single NIC from the list to view more information about that NIC. The information displayed may vary depending on the type of NIC. For example, Ethernet Statistics display for Ethernet adapters.

The following types of information are available depending on the type of NIC:

NIC Controller Information

NIC Interface Information

Ethernet Statistics

Token Ring Statistics

Team of NICs

A team of NICs is composed of two or more physical adapters that present a single, logical interface on the network. Select a NIC team from the navigation frame to view detailed information about that team. The Logical Adapter Information displays by default. You can also select one of the physical adapters in the team to display additional information about that adapter.

There are four kinds of NIC teams:

The logical adapter has two physical adapters associated with it. One physical adapter is active, and the other is a hot standby. If the active physical adapter fails, the other one takes over.

The logical adapter has two or more physical adapters associated with it. One physical adapter is active on the network, and the other physical adapters are hot standbys.

The logical adapter has more than one physical adapter associated with it. One physical adapter transmits and receives data, while the others only transmit. If the receiving adapter fails, one of the other adapters assumes this role.

The logical adapter has more than one physical adapter associated with it. All physical adapters can receive and transmit data. This requires a switch that cooperates with the adapters. If any adapter fails, the load is spread among the remaining adapters.

The following types of information are available for a selected NIC team:

NOTE: This information may vary depending on the type of NIC team selected.

Logical Adapter Information

NIC Controller Information

NIC Interface Information

Ethernet Statistics

Token Ring Statistics

Logical Adapter Information

The following Logical Adapter Information is available for all NIC teams:

Description displays a description of the NIC Team (Compaq Redundant NIC Pair, Compaq Network Fault Tolerance team, Compaq Adaptive Load Balancing team, or Cisco Fast EtherChannel Team).

Status displays the overall status of the NIC team.

Group Type displays the group type of the NIC team (Redundant Pair, Network Fault Tolerance, Adaptive Load Balancing, or Fast EtherChannel).

Switchover Mode displays the method used to determine when traffic switches from one adapter to another. There are three types of Switchover Modes:

NIC Controller Information

The following information displays about NIC controllers.

Model displays the NIC controller model, such as Compaq NetFlex-2 Controller. Use this information for identification purposes.

Status displays three valid states:

Slot displays the physical location of the NIC. For example, if this value is 3, then the NIC is located in slot 3 of your computer. Use this information for identification purposes.

The NIC interface slot value is Embedded if the NIC is integrated onto the system board. If the slot is unknown, or if the NIC is an ISA card, the slot value is N/A.

Port number is 1 for a single-headed NIC, or the port number for a multiple-headed NIC.

Duplex displays the current state of the Full Duplex Ethernet Support. Compaq NICs support the Full Duplex Ethernet if they are attached to a device that also supports Full Duplex.

The following duplex values are possible:

Base I/O Address specifies the starting address of the I/O port used to communicate with this device. Use this information for identification purposes. This I/O port address cannot be used by any other device.

IRQ displays the hardware interrupt that this NIC uses to communicate with the device driver. Use this information for reference purposes.

Base Memory Address displays the base memory address used by this NIC. If this device does not use system memory, or if this information is unavailable, this item is
N/A. Use this information for identification purposes.

DMA Channel displays the number of the DMA channel used for this NIC. If this device does not use a DMA channel, or if this information is unavailable, this item is N/A. Use this information for identification purposes.

Physical (MAC) Address displays the physical address presented on the network by the physical adapter.

NIC Interface Information

This section displays the following information:

IP Address displays the IP address of the logical interface.

Type displays the type of interface, such as Ethernet or Token Ring. The type is distinguished according to the physical link protocol immediately below the network layer in the protocol stack.

NetWare is equivalent to the Frame Type. Not all frame types can be used with all protocols. Additionally, the device and client must use the same frame type to communicate. If you receive the "File server not found" message, ensure that your frame type is the same for the server and the client.

Windows NT is equivalent to the Media Type. If you are having difficulty communicating with other stations or devices on the network, ensure that the media type is the same as other stations on the network.

Interface Status displays one of the following states:

Max Packet Size displays the maximum allowable packet size in bytes. Use this information to compare with other stations. In general, if you are using a high data transfer application, a higher Max Packet Size provides better performance.

If this item is 0, it cannot be obtained from the hardware or support software.

Last Status Change displays the time at which the interface entered its current operational state. Use this item to determine the length of time the interface has remained in its current state. If the time at which the interface entered its current operational state is unknown, N/A displays in this field.

Physical (MAC) Address displays the physical address presented on the network by the physical adapter. This physical address resource cannot be used by any other device. The address is usually burned onto the board, and can be used to map into network analyzer tools.

Speed displays the nominal rate of speed of the NIC in megabits per second. For example, Token Ring speeds are typically 4 or 16 Mb/s. Ethernet speed is typically 10 or 100 Mb/s. If this item is 0, the speed may be 0, or this item cannot be obtained from the hardware or support software.

Use this information to help you determine the configuration of the NIC. If you see an error in the Ring Open Status, found on the Token Ring Status window, you may want to check the configured speed. It is possible that you have set the NIC at the wrong speed if you see Beaconing or Ring Failed under Ring Open Status. For example, there is a conflict if the NIC is configured at 4 megabits per second and the Token Ring is set at 16 megabits per second.

Receive Statistics

Transmit Statistics

Ethernet Statistics

Information about Receive Errors and Transmit Errors is displayed in this window. Information that cannot be obtained from the hardware or support software is indicated by N/A.

Receive Errors

If the item is 0, the total errors received may be 0, or this item cannot be obtained from the hardware or support software.

Track and resolve these errors. The two primary causes of FCS errors are cabling and component problems.

If you receive FCS Errors, check to see whether you have Alignment errors or Late Collision errors. Cabling problems, such as shorts or noise caused by electromagnetic interference, are most likely to blame for CRC/Alignment errors. Improper cabling (not following cable specifications) is the most likely cause for late collisions.

  1. Ensure you have the latest revision of the LAN driver. Oversized frames may be caused by a faulty LAN driver.

  2. Check your routers. If a router connects two dissimilar network types and does not enforce the proper frame size restrictions on either side, it may transmit illegal-length frames. Check with the router manufacturer.

  3. Use a network analyzer to find the NIC responsible for sending illegal-length frames. Examine the 48-bit source address in the frame header; this will pinpoint the responsible NIC.

Transmit Errors

If the item is 0, the total errors transmitted may be 0 or this item cannot be obtained from the hardware or support software.

Late collisions may be an indication that a segment is longer than allowed by the wiring specifications. For example, if you are using 10Base-2 wiring, also known as Thinnet, the maximum segment length is 185 meters.

A station will believe it has control of the cable segment if it has already transmitted 64 bytes. If another node at the far end of the segment has not yet seen the packet, and transmits, this packet will collide with the first transmission after the first 64 bytes have been sent.

Ensure that your segment length does not exceed the maximum length allowed.

Because the location of cabling problems can be very difficult to detect on an Ethernet network, shorten an Ethernet segment (remove portions of the network to isolate problems) until the problems are no longer seen, and then expand the network until the problem recurs.

If you see an increase in deferred transmissions as well as excessive collisions, your network is extremely busy and this segment of the LAN is overcrowded. Reduce the traffic by reorganizing your LAN or adding a NIC to the device. For example, if you have 100 stations on one Ethernet bus, you may want to break it into two Ethernet buses by adding a NIC to your device. In this way you can balance the load by putting 50 stations on one bus and 50 on the other. If there are a few isolated stations creating the traffic, put those stations on a separate bus.

Faulty components may be the cause of excessive collisions.

Deferred transmissions occur when the network is extremely busy. High counts of multiple collisions and excessive collisions also occur.

Deferred transmissions indicate that this segment of the LAN is overcrowded. Reduce the traffic by reorganizing the LAN. For example, if you have 100 stations on one Ethernet bus, break the bus into two Ethernet buses by adding a NIC to your device. This balances the load by putting 50 stations on one bus and 50 on the other. If a few isolated stations create the traffic, put them on a separate bus.

Token Ring Statistics

The following Token Ring Statistics are displayed in this window. Information that cannot be obtained from the hardware or support software is indicated by N/A.

These errors may occur if another station inserts itself into a ring or removes itself from the ring, interrupting the clock cycle. Large noise spikes, such as lightning, could also cause these errors.

If you see excessive Lost Frame errors, there may be a problem with the Multi-Access Unit (MAU) or hub. Use a network analyzer to isolate the problem area.

Excessive traffic to a specific station may cause Receive Congestion Errors. If certain stations continue to experience Receive Congestion Errors, check the network design. It is also possible that the software on the PC is not running efficiently enough to handle interrupts from the network.

If you cannot find the problem after checking the above conditions, use a network analyzer to isolate the station corrupting the frame. The analyzer should indicate which station is causing the problem and let you know if the NIC should be replaced.

The break is detected by the station immediately downstream of the break when that station stops receiving tokens or frames. This station then sends a series of beacon frames around the ring to notify the ring that a break has occurred immediately upstream.

A network analyzer will help to pinpoint the station that is sending the beacon frames and identify which station is directly upstream of the station sending the beacon.

An aborted transmit occurs if the NIC is unable to complete the transmission of a frame that it has already started onto the network. For example, if the NIC was unable to access its packet buffer memory fast enough to keep pace with sending the data stream onto the wire, the NIC will abort the transmit. When a NIC aborts the transmit, it places a special bits sequence on the wire known as an abort delimiter, which signals to other stations on the Token Ring that the packet data is invalid.

Many NICs do not support aborting transmits, preferring instead to shut down with a fatal error and remove the NIC from the ring. Those NICs that support aborting transmits will report this error.

If this error is reported, run the diagnostics from the NIC manufacturer to see if there is a problem.

If the Transmit Beacons count is incrementing as well, then this interface is sending beacons on the network. If Transmit Beacons is not incrementing, then this interface is not transmitting beacons, but detecting beacons being sent.

A network analyzer will help to pinpoint the station that is sending the beacon frames and identify which station is directly upstream of the station sending the beacon.

Perform the following steps:

  1. Check the station immediately upstream from the station that is sending the beacon. Swap out the transceiver, transceiver cable, and transceiver attachment point, one at a time. If you find a faulty component, replace it.

  2. Check the receiver on the station that sent out the beacon frames to ensure that it is capable of receiving frames. If the receiver is not working properly, the NIC may have erroneously assumed that there were no frames or tokens. Run diagnostics from the NIC manufacturer to help you pinpoint the problem.

  3. Check the cabling for breaks or disruptions.

  4. Your Multi-Access Unit (MAU) or hub may be at fault. Use the diagnostics from the MAU manufacturer to determine if a problem exists.

If a Lobe Wire Fault occurs, check for the following:

  1. If your NIC is continuously transmitting, it will cause erroneous signals or "jabber." Replace a jabbering receiver to ensure proper network performance.

  2. Swap out the transceiver, transceiver cable, and transceiver attachment point, one at a time. If you find a faulty component, replace it.

  3. Your Multi-Access Unit (MAU) or hub may be at fault. Use the diagnostics from the MAU manufacturer to determine if a problem exists.

If you detect that one station has an abnormally high burst error count compared to other stations, you may need to replace the NIC. For example, if most stations average 2 burst errors per day, and one station shows 27, that station may have a faulty NIC. The station that is directly downstream of the device causing the problem usually detects the burst error. Use the Upstream Address of the station detecting Burst Errors to determine the faulty NIC.

If excessive burst errors continue to occur on the ring, you may need to replace the Multi-Access Unit (MAU) or hub. Use a network analyzer to isolate the problem area.

The active monitor generates a clock signal, which it passes to each standby monitor. The standby monitor compares this signal to its own reference clock. If the signal is not within the proper frequency boundaries, a frequency error occurs.

NOTE: Not all stations will report this error because not all NIC manufacturers support this feature. A frequency error is not common. If there is a problem with the active monitor, other errors usually occur that help you determine the station that is at fault.

If you see frequency errors, use a network analyzer to determine which station was the active monitor causing the problem. Remember when you use your analyzer that the station with the problem is not the current active monitor the active monitor experiencing the problem was replaced when the problem was detected.

If an AC error occurs, perform the following steps during your next planned maintenance:

  1. Ensure that the NIC is compliant with the protocol in use. The NIC that did not set the bit (the station directly upstream of the station that reported the problem) is not participating in the low level protocol and may not be completely compliant with 802.5 protocol.

  2. Replace the NIC to see if the problem still occurs.