Exact meaning of RX 'errors' and 'frame' in ifconfig output?

Question

I'm seeing network problems with a (RHEL) node (packets dropped), which also seem to manifest themselves by a non-zero count of the 'error' and 'frame' fields in ifconfig output:

eth2      Link encap:Ethernet  HWaddr xx:xx:xx:xx:xx:xx  
          ...
          RX packets:277593775 errors:1049 dropped:0 overruns:0 frame:536

Is there a detailed description somewhere what the exact meaning of 'errors' and 'frame' is ?

EDIT: output of ethtool eth2:

Settings for eth2:
        Supported ports: [ TP ]
        Supported link modes:   10baseT/Half 10baseT/Full 
                                100baseT/Half 100baseT/Full 
                                1000baseT/Full 
        Supports auto-negotiation: Yes
        Advertised link modes:  10baseT/Half 10baseT/Full 
                                100baseT/Half 100baseT/Full 
                                1000baseT/Full 
        Advertised auto-negotiation: Yes
        Speed: 1000Mb/s
        Duplex: Full
        Port: Twisted Pair
        PHYAD: 0
        Transceiver: internal
        Auto-negotiation: on
        Supports Wake-on: umbg
        Wake-on: d
        Current message level: 0x00000007 (7)
        Link detected: yes

Solution 1

RX errors mean that your NIC is receiving malformed frames from the transmitting switchport.

Frame errors mean CRC failures on receipt of a frame. The root cause of this could be a bad cable, or a bad interface on either the machine or the switch. Try replacing the cable, then moving to another port on the switch.

Solution 2

In the tigon (tg3) driver, prior to version v3.134b rxbds_empty events were logged as frame errors.

You can check this via:

ethtool -S {device}

e.g.:

[root@srv2-mgmt ~]# ethtool -S em1
NIC statistics:
     rx_octets: 795609182
     rx_fragments: 0
     rx_ucast_packets: 4003807
     rx_mcast_packets: 313481
     rx_bcast_packets: 1906658
     rx_fcs_errors: 0
     rx_align_errors: 0
     rx_xon_pause_rcvd: 0
     rx_xoff_pause_rcvd: 0
     rx_mac_ctrl_rcvd: 0
     rx_xoff_entered: 0
     rx_frame_too_long_errors: 0
     rx_jabbers: 0
     rx_undersize_packets: 0
     rx_in_length_errors: 0
     rx_out_length_errors: 0
     rx_64_or_less_octet_packets: 0
     rx_65_to_127_octet_packets: 0
     rx_128_to_255_octet_packets: 0
     rx_256_to_511_octet_packets: 0
     rx_512_to_1023_octet_packets: 0
     rx_1024_to_1522_octet_packets: 0
     rx_1523_to_2047_octet_packets: 0
     rx_2048_to_4095_octet_packets: 0
     rx_4096_to_8191_octet_packets: 0
     rx_8192_to_9022_octet_packets: 0
     tx_octets: 1010597527
     tx_collisions: 0
     tx_xon_sent: 0
     tx_xoff_sent: 0
     tx_flow_control: 0
     tx_mac_errors: 0
     tx_single_collisions: 0
     tx_mult_collisions: 0
     tx_deferred: 0
     tx_excessive_collisions: 0
     tx_late_collisions: 0
     tx_collide_2times: 0
     tx_collide_3times: 0
     tx_collide_4times: 0
     tx_collide_5times: 0
     tx_collide_6times: 0
     tx_collide_7times: 0
     tx_collide_8times: 0
     tx_collide_9times: 0
     tx_collide_10times: 0
     tx_collide_11times: 0
     tx_collide_12times: 0
     tx_collide_13times: 0
     tx_collide_14times: 0
     tx_collide_15times: 0
     tx_ucast_packets: 4116171
     tx_mcast_packets: 145500
     tx_bcast_packets: 1983
     tx_carrier_sense_errors: 0
     tx_discards: 0
     tx_errors: 0
     dma_writeq_full: 0
     dma_write_prioq_full: 0
     rxbds_empty: 0
     rx_discards: 0
     rx_errors: 0
     rx_threshold_hit: 0
     dma_readq_full: 0
     dma_read_prioq_full: 0
     tx_comp_queue_full: 0
     ring_set_send_prod_index: 0
     ring_status_update: 0
     nic_irqs: 0
     nic_avoided_irqs: 0
     nic_tx_threshold_hit: 0
     mbuf_lwm_thresh_hit: 0

Comments

[Daniele Santi]

Could be a duplex mismatch. Can you post the output of ethtool eth2 ?

[Andre Holzner]

thanks for the answer. I would think that a malformed frame does not have a correct CRC either. What does it need to be malformed ? If there is no/badly sized preamble after the interframe gap or no frame delimiter after the preamble ? or the next interframe gap comes too early/late with respect to the length found in the ethertype/length field ?

[Murali Suriar]

Any of the above. I'm not sure why I put in 'malformed or otherwise incorrect'. You're right, they mean exactly the same thing. Answer updated.

[B.Mr.W.]

@MuraliSuriar I am using 10G NIC and the number of dropped and frames are the same, but number of errors are 0, ` RX packets:17051276 errors:0 dropped:476 overruns:0 frame:476`, can you tell me what could be the possible reason in this case?