[ale] Sporadic TCP/IP packet loss

[Ryan Fish]

OS: RHEL3 ES
HW: Dell PE1750, Intel dual port NIC

Since early yesterday morning I have been experiencing a lot of sporadic TCP/IP packet drops on a server in my environment.  No changes were made to the network, the server, the NIC, etc. and all was working fine before Monday.  I have found nothing in the logs on either the server or the switch to which it is connected that point to anything as of yet.  These drops can last as little as two seconds and as long as a couple minutes however the server always comes back online eventually.  I am drawing a blank and am hoping someone can prod me in the right direction...

ifconfig shows:
eth0      Link encap:Ethernet  HWaddr 00:0B:DB:91:DB:1E
          inet addr:192.168.3.221  Bcast:192.168.3.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:89190 errors:0 dropped:0 overruns:0 frame:0
          TX packets:90540 errors:0 dropped:0 overruns:0 carrier:0
          collisions:4 txqueuelen:1000
          RX bytes:48549091 (46.3 Mb)  TX bytes:22576751 (21.5 Mb)
          Interrupt:16

netstat -ns shows:
Ip:
    795317 total packets received
    0 forwarded
    0 incoming packets discarded
    775609 incoming packets delivered
    804079 requests sent out
    24573 reassemblies required
    7823 packets reassembled ok
    681 fragments received ok
Icmp:
    3410 ICMP messages received
    127 input ICMP message failed.
    ICMP input histogram:
        destination unreachable: 519
        echo requests: 2435
        echo replies: 445
    2954 ICMP messages sent
    0 ICMP messages failed
    ICMP output histogram:
        destination unreachable: 519
        echo replies: 2435
Tcp:
    318 active connections openings
    1632 passive connection openings
    127 failed connection attempts
    54 connection resets received
    11 connections established
    716980 segments received
    742124 segments send out
    194 segments retransmited
    1 bad segments received.
    69 resets sent
Udp:
    58157 packets received
    0 packets to unknown port received.
    0 packet receive errors
    58321 packets sent
TcpExt:
    2 resets received for embryonic SYN_RECV sockets
    ArpFilter: 0
    1456 TCP sockets finished time wait in fast timer
    5060 delayed acks sent
    Quick ack mode was activated 3 times
    682638 packets directly queued to recvmsg prequeue.
    8973 packets directly received from backlog
    551315 packets directly received from prequeue
    696140 packets header predicted
    737 packets header predicted and directly queued to user
    TCPPureAcks: 5778
    TCPHPAcks: 691815
    TCPRenoRecovery: 0
    TCPSackRecovery: 2
    TCPSACKReneging: 0
    TCPFACKReorder: 0
    TCPSACKReorder: 0
    TCPRenoReorder: 0
    TCPTSReorder: 0
    TCPFullUndo: 0
    TCPPartialUndo: 0
    TCPDSACKUndo: 0
    TCPLossUndo: 0
    TCPLoss: 2
    TCPLostRetransmit: 0
    TCPRenoFailures: 0
    TCPSackFailures: 1
    TCPLossFailures: 0
    TCPFastRetrans: 2
    TCPForwardRetrans: 0
    TCPSlowStartRetrans: 0
    TCPTimeouts: 128
    TCPRenoRecoveryFail: 0
    TCPSackRecoveryFail: 0
    TCPSchedulerFailed: 0
    TCPRcvCollapsed: 0
    TCPDSACKOldSent: 4
    TCPDSACKOfoSent: 0
    TCPDSACKRecv: 1
    TCPDSACKOfoRecv: 0
    TCPAbortOnSyn: 0
    TCPAbortOnData: 50
    TCPAbortOnClose: 1
    TCPAbortOnMemory: 0
    TCPAbortOnTimeout: 1
    TCPAbortOnLinger: 0
    TCPAbortFailed: 0
    TCPMemoryPressures: 0

ethtool shows:
Settings for eth0:
        Supported ports: [ MII ]
        Supported link modes:   10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full
                                1000baseT/Half 1000baseT/Full
        Supports auto-negotiation: Yes
        Advertised link modes:  Not reported
        Advertised auto-negotiation: No
        Speed: 100Mb/s
        Duplex: Full
        Port: Twisted Pair
        PHYAD: 1
        Transceiver: internal
        Auto-negotiation: off
        Supports Wake-on: g
        Wake-on: d
        Current message level: 0x000000ff (255)
        Link detected: yes

mii-tool shows:
eth0: 100 Mbit, full duplex, link ok

Any assistance will be GREATLY appreciated.

Thank you.
-Ryan