Como investigar uma redefinição aleatória na porta do cliente TCP conectada via interface de loopback para um servidor

Question

Como investigar uma redefinição aleatória na porta do cliente TCP conectada via interface de loopback para um servidor

#1 resposta do (1 votos)

10

Eu tenho um conjunto de testes que inicializa um servidor no host local e, em seguida, executa milhares de testes de estresse, que incluem iniciar e parar os clientes que se conectam a esse servidor local na mesma máquina. Eu estou tentando encontrar o motivo de um RST enviado pelo cliente para o servidor.

Esta é a sequência de eventos:

cliente inicializa o SYN
O servidor envia de volta SYN, ACK
cliente envia RST (em vez de ACK e estabelece conexão)

Uma observação é em muitas ocasiões em que os servidores são executados em torno de 99% da CPU, embora retornem ao normal em poucos segundos / minutos.

Inicialmente, pensei que isso poderia ser porque o cliente está usando uma porta da conexão anteriormente fechada, que está no estado TIME_WAIT e, portanto, quando o servidor envia um SYN, o ACK nesse cliente de conexão emite o RST. Embora eu fosse cético quanto ao motivo pelo qual o cliente deveria usar uma porta no estado TIME_WAIT, mas eu estou usando o antigo fedora core 4 e pensei que talvez não tenha uma implementação adequada do TCP / IP: -).

Agora, não acredito que essa seja a razão, porque toda a sintonia feita na correção da questão acima não ajudou a aliviar o problema. Seguem as alterações que tentei em /etc/sysctl.conf :

net.ipv4.ip_local_port_range = 1024     65535
net.ipv4.tcp_fin_timeout = 15
net.ipv4.tcp_rfc1337 = 1
net.ipv4.tcp_tw_reuse = 1

Mais um ponto, esse problema não é consistente. Na verdade, só posso reproduzir esse problema depois de passar de 15 a 35 ciclos de Re-iniciar o servidor e executar todos os testes do cliente.

Eu fiquei sem todos os motivos pelos quais isso pode estar acontecendo, então me avise se alguém tiver alguma ideia do que pode estar acontecendo.

Detalhes do pacote

Date & Time                No.     Time        Source                Destination           Protocol Length Source port Dest port Info
2014-06-25 14:49:45.378209 1032719 1858.494749 ::1                   ::1                   TCP      94     netview-aix-5 navisphere netview-aix-5 > navisphere [SYN] Seq=0 Win=32752 Len=0 MSS=16376 SACK_PERM=1 TSval=1587252 TSecr=0 WS=128

Frame 1032719: 94 bytes on wire (752 bits), 94 bytes captured (752 bits)
    Arrival Time: Jun 25, 2014 14:49:45.378209000 EDT
    Epoch Time: 1403722185.378209000 seconds
    [Time delta from previous captured frame: 0.005893000 seconds]
    [Time delta from previous displayed frame: 0.000000000 seconds]
    [Time since reference or first frame: 1858.494749000 seconds]
    Frame Number: 1032719
    Frame Length: 94 bytes (752 bits)
    Capture Length: 94 bytes (752 bits)
    [Frame is marked: False]
    [Frame is ignored: False]
    [Protocols in frame: eth:ipv6:tcp]
    [Coloring Rule Name: TCP SYN/FIN]
    [Coloring Rule String: tcp.flags & 0x02 || tcp.flags.fin == 1]
Ethernet II, Src: 00:00:00_00:00:00 (00:00:00:00:00:00), Dst: 00:00:00_00:00:00 (00:00:00:00:00:00)
    Destination: 00:00:00_00:00:00 (00:00:00:00:00:00)
        Address: 00:00:00_00:00:00 (00:00:00:00:00:00)
        .... ...0 .... .... .... .... = IG bit: Individual address (unicast)
        .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
    Source: 00:00:00_00:00:00 (00:00:00:00:00:00)
        Address: 00:00:00_00:00:00 (00:00:00:00:00:00)
        .... ...0 .... .... .... .... = IG bit: Individual address (unicast)
        .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
    Type: IPv6 (0x86dd)
Internet Protocol Version 6, Src: ::1 (::1), Dst: ::1 (::1)
    0110 .... = Version: 6
        [0110 .... = This field makes the filter "ip.version == 6" possible: 6]
    .... 0000 0000 .... .... .... .... .... = Traffic class: 0x00000000
        .... 0000 00.. .... .... .... .... .... = Differentiated Services Field: Default (0x00000000)
        .... .... ..0. .... .... .... .... .... = ECN-Capable Transport (ECT): Not set
        .... .... ...0 .... .... .... .... .... = ECN-CE: Not set
    .... .... .... 0000 0000 0000 0000 0000 = Flowlabel: 0x00000000
    Payload length: 40
    Next header: TCP (0x06)
    Hop limit: 64
    Source: ::1 (::1)
    Destination: ::1 (::1)
Transmission Control Protocol, Src Port: netview-aix-5 (1665), Dst Port: navisphere (2162), Seq: 0, Len: 0
    Source port: netview-aix-5 (1665)
    Destination port: navisphere (2162)
    [Stream index: 3374]
    Sequence number: 0    (relative sequence number)
    Header length: 40 bytes
    Flags: 0x02 (SYN)
        000. .... .... = Reserved: Not set
        ...0 .... .... = Nonce: Not set
        .... 0... .... = Congestion Window Reduced (CWR): Not set
        .... .0.. .... = ECN-Echo: Not set
        .... ..0. .... = Urgent: Not set
        .... ...0 .... = Acknowledgement: Not set
        .... .... 0... = Push: Not set
        .... .... .0.. = Reset: Not set
        .... .... ..1. = Syn: Set
            [Expert Info (Chat/Sequence): Connection establish request (SYN): server port navisphere]
        .... .... ...0 = Fin: Not set
    Window size value: 32752
    [Calculated window size: 32752]
    Checksum: 0xf489 [validation disabled]
        [Good Checksum: False]
        [Bad Checksum: False]
    Options: (20 bytes)
        Maximum segment size: 16376 bytes
        TCP SACK Permitted Option: True
        Timestamps: TSval 1587252, TSecr 0
        No-Operation (NOP)
        Window scale: 7 (multiply by 128)

Date & Time                No.     Time        Source                Destination           Protocol Length Source port Dest port Info
2014-06-25 14:49:45.378222 1032720 1858.494762 ::1                   ::1                   TCP      94     navisphere  netview-aix-5 navisphere > netview-aix-5 [SYN, ACK] Seq=0 Ack=1 Win=32728 Len=0 MSS=16376 SACK_PERM=1 TSval=1587252 TSecr=1587252 WS=128

Frame 1032720: 94 bytes on wire (752 bits), 94 bytes captured (752 bits)
    Arrival Time: Jun 25, 2014 14:49:45.378222000 EDT
    Epoch Time: 1403722185.378222000 seconds
    [Time delta from previous captured frame: 0.000013000 seconds]
    [Time delta from previous displayed frame: 0.000013000 seconds]
    [Time since reference or first frame: 1858.494762000 seconds]
    Frame Number: 1032720
    Frame Length: 94 bytes (752 bits)
    Capture Length: 94 bytes (752 bits)
    [Frame is marked: False]
    [Frame is ignored: False]
    [Protocols in frame: eth:ipv6:tcp]
    [Coloring Rule Name: TCP SYN/FIN]
    [Coloring Rule String: tcp.flags & 0x02 || tcp.flags.fin == 1]
Ethernet II, Src: 00:00:00_00:00:00 (00:00:00:00:00:00), Dst: 00:00:00_00:00:00 (00:00:00:00:00:00)
    Destination: 00:00:00_00:00:00 (00:00:00:00:00:00)
        Address: 00:00:00_00:00:00 (00:00:00:00:00:00)
        .... ...0 .... .... .... .... = IG bit: Individual address (unicast)
        .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
    Source: 00:00:00_00:00:00 (00:00:00:00:00:00)
        Address: 00:00:00_00:00:00 (00:00:00:00:00:00)
        .... ...0 .... .... .... .... = IG bit: Individual address (unicast)
        .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
    Type: IPv6 (0x86dd)
Internet Protocol Version 6, Src: ::1 (::1), Dst: ::1 (::1)
    0110 .... = Version: 6
        [0110 .... = This field makes the filter "ip.version == 6" possible: 6]
    .... 0000 0000 .... .... .... .... .... = Traffic class: 0x00000000
        .... 0000 00.. .... .... .... .... .... = Differentiated Services Field: Default (0x00000000)
        .... .... ..0. .... .... .... .... .... = ECN-Capable Transport (ECT): Not set
        .... .... ...0 .... .... .... .... .... = ECN-CE: Not set
    .... .... .... 0000 0000 0000 0000 0000 = Flowlabel: 0x00000000
    Payload length: 40
    Next header: TCP (0x06)
    Hop limit: 64
    Source: ::1 (::1)
    Destination: ::1 (::1)
Transmission Control Protocol, Src Port: navisphere (2162), Dst Port: netview-aix-5 (1665), Seq: 0, Ack: 1, Len: 0
    Source port: navisphere (2162)
    Destination port: netview-aix-5 (1665)
    [Stream index: 3374]
    Sequence number: 0    (relative sequence number)
    Acknowledgement number: 1    (relative ack number)
    Header length: 40 bytes
    Flags: 0x12 (SYN, ACK)
        000. .... .... = Reserved: Not set
        ...0 .... .... = Nonce: Not set
        .... 0... .... = Congestion Window Reduced (CWR): Not set
        .... .0.. .... = ECN-Echo: Not set
        .... ..0. .... = Urgent: Not set
        .... ...1 .... = Acknowledgement: Set
        .... .... 0... = Push: Not set
        .... .... .0.. = Reset: Not set
        .... .... ..1. = Syn: Set
            [Expert Info (Chat/Sequence): Connection establish acknowledge (SYN+ACK): server port navisphere]
        .... .... ...0 = Fin: Not set
    Window size value: 32728
    [Calculated window size: 32728]
    Checksum: 0xf7fa [validation disabled]
        [Good Checksum: False]
        [Bad Checksum: False]
    Options: (20 bytes)
        Maximum segment size: 16376 bytes
        TCP SACK Permitted Option: True
        Timestamps: TSval 1587252, TSecr 1587252
        No-Operation (NOP)
        Window scale: 7 (multiply by 128)
    [SEQ/ACK analysis]
        [This is an ACK to the segment in frame: 1032719]
        [The RTT to ACK the segment was: 0.000013000 seconds]

Date & Time                No.     Time        Source                Destination           Protocol Length Source port Dest port Info
2014-06-25 14:49:45.378228 1032721 1858.494768 ::1                   ::1                   TCP      74     netview-aix-5 navisphere netview-aix-5 > navisphere [RST] Seq=1 Win=0 Len=0

Frame 1032721: 74 bytes on wire (592 bits), 74 bytes captured (592 bits)
    Arrival Time: Jun 25, 2014 14:49:45.378228000 EDT
    Epoch Time: 1403722185.378228000 seconds
    [Time delta from previous captured frame: 0.000006000 seconds]
    [Time delta from previous displayed frame: 0.000006000 seconds]
    [Time since reference or first frame: 1858.494768000 seconds]
    Frame Number: 1032721
    Frame Length: 74 bytes (592 bits)
    Capture Length: 74 bytes (592 bits)
    [Frame is marked: False]
    [Frame is ignored: False]
    [Protocols in frame: eth:ipv6:tcp]
    [Coloring Rule Name: TCP RST]
    [Coloring Rule String: tcp.flags.reset eq 1]
Ethernet II, Src: 00:00:00_00:00:00 (00:00:00:00:00:00), Dst: 00:00:00_00:00:00 (00:00:00:00:00:00)
    Destination: 00:00:00_00:00:00 (00:00:00:00:00:00)
        Address: 00:00:00_00:00:00 (00:00:00:00:00:00)
        .... ...0 .... .... .... .... = IG bit: Individual address (unicast)
        .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
    Source: 00:00:00_00:00:00 (00:00:00:00:00:00)
        Address: 00:00:00_00:00:00 (00:00:00:00:00:00)
        .... ...0 .... .... .... .... = IG bit: Individual address (unicast)
        .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
    Type: IPv6 (0x86dd)
Internet Protocol Version 6, Src: ::1 (::1), Dst: ::1 (::1)
    0110 .... = Version: 6
        [0110 .... = This field makes the filter "ip.version == 6" possible: 6]
    .... 0000 0000 .... .... .... .... .... = Traffic class: 0x00000000
        .... 0000 00.. .... .... .... .... .... = Differentiated Services Field: Default (0x00000000)
        .... .... ..0. .... .... .... .... .... = ECN-Capable Transport (ECT): Not set
        .... .... ...0 .... .... .... .... .... = ECN-CE: Not set
    .... .... .... 0000 0000 0000 0000 0000 = Flowlabel: 0x00000000
    Payload length: 20
    Next header: TCP (0x06)
    Hop limit: 64
    Source: ::1 (::1)
    Destination: ::1 (::1)
Transmission Control Protocol, Src Port: netview-aix-5 (1665), Dst Port: navisphere (2162), Seq: 1, Len: 0
    Source port: netview-aix-5 (1665)
    Destination port: navisphere (2162)
    [Stream index: 3374]
    Sequence number: 1    (relative sequence number)
    Header length: 20 bytes
    Flags: 0x04 (RST)
        000. .... .... = Reserved: Not set
        ...0 .... .... = Nonce: Not set
        .... 0... .... = Congestion Window Reduced (CWR): Not set
        .... .0.. .... = ECN-Echo: Not set
        .... ..0. .... = Urgent: Not set
        .... ...0 .... = Acknowledgement: Not set
        .... .... 0... = Push: Not set
        .... .... .1.. = Reset: Set
            [Expert Info (Chat/Sequence): Connection reset (RST)]
        .... .... ..0. = Syn: Not set
        .... .... ...0 = Fin: Not set
    Window size value: 0
    [Calculated window size: 0]
    [Window size scaling factor: 128]
    Checksum: 0x4eea [validation disabled]
        [Good Checksum: False]
        [Bad Checksum: False]

Date & Time                No.     Time        Source                Destination           Protocol Length Source port Dest port Info
2014-06-25 14:49:48.375927 1032722 1861.492467 ::1                   ::1                   TCP      94     netview-aix-5 navisphere netview-aix-5 > navisphere [SYN] Seq=0 Win=32752 Len=0 MSS=16376 SACK_PERM=1 TSval=1588002 TSecr=0 WS=128

Frame 1032722: 94 bytes on wire (752 bits), 94 bytes captured (752 bits)
    Arrival Time: Jun 25, 2014 14:49:48.375927000 EDT
    Epoch Time: 1403722188.375927000 seconds
    [Time delta from previous captured frame: 2.997699000 seconds]
    [Time delta from previous displayed frame: 2.997699000 seconds]
    [Time since reference or first frame: 1861.492467000 seconds]
    Frame Number: 1032722
    Frame Length: 94 bytes (752 bits)
    Capture Length: 94 bytes (752 bits)
    [Frame is marked: False]
    [Frame is ignored: False]
    [Protocols in frame: eth:ipv6:tcp]
    [Coloring Rule Name: TCP SYN/FIN]
    [Coloring Rule String: tcp.flags & 0x02 || tcp.flags.fin == 1]
Ethernet II, Src: 00:00:00_00:00:00 (00:00:00:00:00:00), Dst: 00:00:00_00:00:00 (00:00:00:00:00:00)
    Destination: 00:00:00_00:00:00 (00:00:00:00:00:00)
        Address: 00:00:00_00:00:00 (00:00:00:00:00:00)
        .... ...0 .... .... .... .... = IG bit: Individual address (unicast)
        .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
    Source: 00:00:00_00:00:00 (00:00:00:00:00:00)
        Address: 00:00:00_00:00:00 (00:00:00:00:00:00)
        .... ...0 .... .... .... .... = IG bit: Individual address (unicast)
        .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
    Type: IPv6 (0x86dd)
Internet Protocol Version 6, Src: ::1 (::1), Dst: ::1 (::1)
    0110 .... = Version: 6
        [0110 .... = This field makes the filter "ip.version == 6" possible: 6]
    .... 0000 0000 .... .... .... .... .... = Traffic class: 0x00000000
        .... 0000 00.. .... .... .... .... .... = Differentiated Services Field: Default (0x00000000)
        .... .... ..0. .... .... .... .... .... = ECN-Capable Transport (ECT): Not set
        .... .... ...0 .... .... .... .... .... = ECN-CE: Not set
    .... .... .... 0000 0000 0000 0000 0000 = Flowlabel: 0x00000000
    Payload length: 40
    Next header: TCP (0x06)
    Hop limit: 64
    Source: ::1 (::1)
    Destination: ::1 (::1)
Transmission Control Protocol, Src Port: netview-aix-5 (1665), Dst Port: navisphere (2162), Seq: 0, Len: 0
    Source port: netview-aix-5 (1665)
    Destination port: navisphere (2162)
    [Stream index: 3374]
    Sequence number: 0    (relative sequence number)
    Header length: 40 bytes
    Flags: 0x02 (SYN)
        000. .... .... = Reserved: Not set
        ...0 .... .... = Nonce: Not set
        .... 0... .... = Congestion Window Reduced (CWR): Not set
        .... .0.. .... = ECN-Echo: Not set
        .... ..0. .... = Urgent: Not set
        .... ...0 .... = Acknowledgement: Not set
        .... .... 0... = Push: Not set
        .... .... .0.. = Reset: Not set
        .... .... ..1. = Syn: Set
            [Expert Info (Chat/Sequence): Connection establish request (SYN): server port navisphere]
        .... .... ...0 = Fin: Not set
    Window size value: 32752
    [Calculated window size: 32752]
    Checksum: 0xf19b [validation disabled]
        [Good Checksum: False]
        [Bad Checksum: False]
    Options: (20 bytes)
        Maximum segment size: 16376 bytes
        TCP SACK Permitted Option: True
        Timestamps: TSval 1588002, TSecr 0
        No-Operation (NOP)
        Window scale: 7 (multiply by 128)

Date & Time                No.     Time        Source                Destination           Protocol Length Source port Dest port Info
2014-06-25 14:49:48.375950 1032723 1861.492490 ::1                   ::1                   TCP      94     navisphere  netview-aix-5 [TCP Previous segment lost] navisphere > netview-aix-5 [SYN, ACK] Seq=2997725 Ack=1 Win=32728 Len=0 MSS=16376 SACK_PERM=1 TSval=1588002 TSecr=1588002 WS=128

Frame 1032723: 94 bytes on wire (752 bits), 94 bytes captured (752 bits)
    Arrival Time: Jun 25, 2014 14:49:48.375950000 EDT
    Epoch Time: 1403722188.375950000 seconds
    [Time delta from previous captured frame: 0.000023000 seconds]
    [Time delta from previous displayed frame: 0.000023000 seconds]
    [Time since reference or first frame: 1861.492490000 seconds]
    Frame Number: 1032723
    Frame Length: 94 bytes (752 bits)
    Capture Length: 94 bytes (752 bits)
    [Frame is marked: False]
    [Frame is ignored: False]
    [Protocols in frame: eth:ipv6:tcp]
    [Coloring Rule Name: Bad TCP]
    [Coloring Rule String: tcp.analysis.flags]
Ethernet II, Src: 00:00:00_00:00:00 (00:00:00:00:00:00), Dst: 00:00:00_00:00:00 (00:00:00:00:00:00)
    Destination: 00:00:00_00:00:00 (00:00:00:00:00:00)
        Address: 00:00:00_00:00:00 (00:00:00:00:00:00)
        .... ...0 .... .... .... .... = IG bit: Individual address (unicast)
        .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
    Source: 00:00:00_00:00:00 (00:00:00:00:00:00)
        Address: 00:00:00_00:00:00 (00:00:00:00:00:00)
        .... ...0 .... .... .... .... = IG bit: Individual address (unicast)
        .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
    Type: IPv6 (0x86dd)
Internet Protocol Version 6, Src: ::1 (::1), Dst: ::1 (::1)
    0110 .... = Version: 6
        [0110 .... = This field makes the filter "ip.version == 6" possible: 6]
    .... 0000 0000 .... .... .... .... .... = Traffic class: 0x00000000
        .... 0000 00.. .... .... .... .... .... = Differentiated Services Field: Default (0x00000000)
        .... .... ..0. .... .... .... .... .... = ECN-Capable Transport (ECT): Not set
        .... .... ...0 .... .... .... .... .... = ECN-CE: Not set
    .... .... .... 0000 0000 0000 0000 0000 = Flowlabel: 0x00000000
    Payload length: 40
    Next header: TCP (0x06)
    Hop limit: 64
    Source: ::1 (::1)
    Destination: ::1 (::1)
Transmission Control Protocol, Src Port: navisphere (2162), Dst Port: netview-aix-5 (1665), Seq: 2997725, Ack: 1, Len: 0
    Source port: navisphere (2162)
    Destination port: netview-aix-5 (1665)
    [Stream index: 3374]
    Sequence number: 2997725    (relative sequence number)
    Acknowledgement number: 1    (relative ack number)
    Header length: 40 bytes
    Flags: 0x12 (SYN, ACK)
        000. .... .... = Reserved: Not set
        ...0 .... .... = Nonce: Not set
        .... 0... .... = Congestion Window Reduced (CWR): Not set
        .... .0.. .... = ECN-Echo: Not set
        .... ..0. .... = Urgent: Not set
        .... ...1 .... = Acknowledgement: Set
        .... .... 0... = Push: Not set
        .... .... .0.. = Reset: Not set
        .... .... ..1. = Syn: Set
            [Expert Info (Chat/Sequence): Connection establish acknowledge (SYN+ACK): server port navisphere]
        .... .... ...0 = Fin: Not set
    Window size value: 32728
    [Calculated window size: 32728]
    Checksum: 0x3414 [validation disabled]
        [Good Checksum: False]
        [Bad Checksum: False]
    Options: (20 bytes)
        Maximum segment size: 16376 bytes
        TCP SACK Permitted Option: True
        Timestamps: TSval 1588002, TSecr 1588002
        No-Operation (NOP)
        Window scale: 7 (multiply by 128)
    [SEQ/ACK analysis]
        [This is an ACK to the segment in frame: 1032722]
        [The RTT to ACK the segment was: 0.000023000 seconds]
        [TCP Analysis Flags]
            [A segment before this frame was lost]
                [Expert Info (Warn/Sequence): Previous segment lost (common at capture start)]

Date & Time                No.     Time        Source                Destination           Protocol Length Source port Dest port Info
2014-06-25 14:49:48.375958 1032724 1861.492498 ::1                   ::1                   TCP      74     netview-aix-5 navisphere netview-aix-5 > navisphere [RST] Seq=1 Win=0 Len=0

Frame 1032724: 74 bytes on wire (592 bits), 74 bytes captured (592 bits)
    Arrival Time: Jun 25, 2014 14:49:48.375958000 EDT
    Epoch Time: 1403722188.375958000 seconds
    [Time delta from previous captured frame: 0.000008000 seconds]
    [Time delta from previous displayed frame: 0.000008000 seconds]
    [Time since reference or first frame: 1861.492498000 seconds]
    Frame Number: 1032724
    Frame Length: 74 bytes (592 bits)
    Capture Length: 74 bytes (592 bits)
    [Frame is marked: False]
    [Frame is ignored: False]
    [Protocols in frame: eth:ipv6:tcp]
    [Coloring Rule Name: TCP RST]
    [Coloring Rule String: tcp.flags.reset eq 1]
Ethernet II, Src: 00:00:00_00:00:00 (00:00:00:00:00:00), Dst: 00:00:00_00:00:00 (00:00:00:00:00:00)
    Destination: 00:00:00_00:00:00 (00:00:00:00:00:00)
        Address: 00:00:00_00:00:00 (00:00:00:00:00:00)
        .... ...0 .... .... .... .... = IG bit: Individual address (unicast)
        .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
    Source: 00:00:00_00:00:00 (00:00:00:00:00:00)
        Address: 00:00:00_00:00:00 (00:00:00:00:00:00)
        .... ...0 .... .... .... .... = IG bit: Individual address (unicast)
        .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
    Type: IPv6 (0x86dd)
Internet Protocol Version 6, Src: ::1 (::1), Dst: ::1 (::1)
    0110 .... = Version: 6
        [0110 .... = This field makes the filter "ip.version == 6" possible: 6]
    .... 0000 0000 .... .... .... .... .... = Traffic class: 0x00000000
        .... 0000 00.. .... .... .... .... .... = Differentiated Services Field: Default (0x00000000)
        .... .... ..0. .... .... .... .... .... = ECN-Capable Transport (ECT): Not set
        .... .... ...0 .... .... .... .... .... = ECN-CE: Not set
    .... .... .... 0000 0000 0000 0000 0000 = Flowlabel: 0x00000000
    Payload length: 20
    Next header: TCP (0x06)
    Hop limit: 64
    Source: ::1 (::1)
    Destination: ::1 (::1)
Transmission Control Protocol, Src Port: netview-aix-5 (1665), Dst Port: navisphere (2162), Seq: 1, Len: 0
    Source port: netview-aix-5 (1665)
    Destination port: navisphere (2162)
    [Stream index: 3374]
    Sequence number: 1    (relative sequence number)
    Header length: 20 bytes
    Flags: 0x04 (RST)
        000. .... .... = Reserved: Not set
        ...0 .... .... = Nonce: Not set
        .... 0... .... = Congestion Window Reduced (CWR): Not set
        .... .0.. .... = ECN-Echo: Not set
        .... ..0. .... = Urgent: Not set
        .... ...0 .... = Acknowledgement: Not set
        .... .... 0... = Push: Not set
        .... .... .1.. = Reset: Set
            [Expert Info (Chat/Sequence): Connection reset (RST)]
        .... .... ..0. = Syn: Not set
        .... .... ...0 = Fin: Not set
    Window size value: 0
    [Calculated window size: 0]
    [Window size scaling factor: 128]
    Checksum: 0x4eea [validation disabled]
        [Good Checksum: False]
        [Bad Checksum: False]

Date & Time                No.     Time        Source                Destination           Protocol Length Source port Dest port Info
2014-06-25 14:49:54.376072 1032725 1867.492612 ::1                   ::1                   TCP      94     netview-aix-5 navisphere netview-aix-5 > navisphere [SYN] Seq=0 Win=32752 Len=0 MSS=16376 SACK_PERM=1 TSval=1589502 TSecr=0 WS=128

Frame 1032725: 94 bytes on wire (752 bits), 94 bytes captured (752 bits)
    Arrival Time: Jun 25, 2014 14:49:54.376072000 EDT
    Epoch Time: 1403722194.376072000 seconds
    [Time delta from previous captured frame: 6.000114000 seconds]
    [Time delta from previous displayed frame: 6.000114000 seconds]
    [Time since reference or first frame: 1867.492612000 seconds]
    Frame Number: 1032725
    Frame Length: 94 bytes (752 bits)
    Capture Length: 94 bytes (752 bits)
    [Frame is marked: False]
    [Frame is ignored: False]
    [Protocols in frame: eth:ipv6:tcp]
    [Coloring Rule Name: TCP SYN/FIN]
    [Coloring Rule String: tcp.flags & 0x02 || tcp.flags.fin == 1]
Ethernet II, Src: 00:00:00_00:00:00 (00:00:00:00:00:00), Dst: 00:00:00_00:00:00 (00:00:00:00:00:00)
    Destination: 00:00:00_00:00:00 (00:00:00:00:00:00)
        Address: 00:00:00_00:00:00 (00:00:00:00:00:00)
        .... ...0 .... .... .... .... = IG bit: Individual address (unicast)
        .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
    Source: 00:00:00_00:00:00 (00:00:00:00:00:00)
        Address: 00:00:00_00:00:00 (00:00:00:00:00:00)
        .... ...0 .... .... .... .... = IG bit: Individual address (unicast)
        .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
    Type: IPv6 (0x86dd)
Internet Protocol Version 6, Src: ::1 (::1), Dst: ::1 (::1)
    0110 .... = Version: 6
        [0110 .... = This field makes the filter "ip.version == 6" possible: 6]
    .... 0000 0000 .... .... .... .... .... = Traffic class: 0x00000000
        .... 0000 00.. .... .... .... .... .... = Differentiated Services Field: Default (0x00000000)
        .... .... ..0. .... .... .... .... .... = ECN-Capable Transport (ECT): Not set
        .... .... ...0 .... .... .... .... .... = ECN-CE: Not set
    .... .... .... 0000 0000 0000 0000 0000 = Flowlabel: 0x00000000
    Payload length: 40
    Next header: TCP (0x06)
    Hop limit: 64
    Source: ::1 (::1)
    Destination: ::1 (::1)
Transmission Control Protocol, Src Port: netview-aix-5 (1665), Dst Port: navisphere (2162), Seq: 0, Len: 0
    Source port: netview-aix-5 (1665)
    Destination port: navisphere (2162)
    [Stream index: 3374]
    Sequence number: 0    (relative sequence number)
    Header length: 40 bytes
    Flags: 0x02 (SYN)
        000. .... .... = Reserved: Not set
        ...0 .... .... = Nonce: Not set
        .... 0... .... = Congestion Window Reduced (CWR): Not set
        .... .0.. .... = ECN-Echo: Not set
        .... ..0. .... = Urgent: Not set
        .... ...0 .... = Acknowledgement: Not set
        .... .... 0... = Push: Not set
        .... .... .0.. = Reset: Not set
        .... .... ..1. = Syn: Set
            [Expert Info (Chat/Sequence): Connection establish request (SYN): server port navisphere]
        .... .... ...0 = Fin: Not set
    Window size value: 32752
    [Calculated window size: 32752]
    Checksum: 0xebbf [validation disabled]
        [Good Checksum: False]
        [Bad Checksum: False]
    Options: (20 bytes)
        Maximum segment size: 16376 bytes
        TCP SACK Permitted Option: True
        Timestamps: TSval 1589502, TSecr 0
        No-Operation (NOP)
        Window scale: 7 (multiply by 128)

iptables-save output:

# Generated by iptables-save v1.3.0 on Thu Jun 26 10:15:33 2014
*filter
:FORWARD ACCEPT [0:0]
:INPUT ACCEPT [675:236200]
:OUTPUT ACCEPT [241:21540]
COMMIT
# Completed on Thu Jun 26 10:15:33 2014

fedora tcpdump tcp-ip tcp

por carolinian 25.06.2014 / 22:44

1 resposta

Tags fedora tcpdump tcp-ip tcp

qual é a diferença entre a versão src 3. * e 3. * - genérico Alguém realmente usa e se beneficia de páginas enormes e transparentes?

score 1 · Answer 1

Só quero concluir esta discussão com a solução adotada na ausência de uma correção para a causa raiz que eu estou supondo que esteja na implementação da pilha TCP do Fedora 4. Como solução, eu simplesmente introduzi uma tentativa de reconexão imediata caso a falha seja devida ao ETIMEDOUT e o protocolo usado seja o IPV6. Isso resolveu o problema para mim e minha equipe para sempre, com possível risco de atraso adicional de 3 minutos no relato de erro em qualquer outro problema de conexão, resultando em ETIMEDOUT. Essa não é a solução real / ideal para o problema, mas nos ajuda a seguir em frente ... já que isso afeta nossa suíte de testes automatizada e não é enviado para o cliente. Espero que, eventualmente, alguém que conheça bem a implementação do fedora 4 tcp / ip stack resolva esse mistério para sempre.