Pontos de acesso HP que enviam pacotes multicast de IPs que não são seus próprios

Question

Eu não sou o cara normal da minha rede ... Acabei de ser recrutado para ajudar com esse problema, então, por favor, tenha paciência comigo.

Temos uma rede bastante grande (~ 4.000 dispositivos?) composta principalmente de equipamentos HP Procurve. Ocasionalmente, ao longo das últimas semanas, temos recebido alguns tempestades de transmissão que praticamente impedem que todo o tráfego restante seja enviado pela rede. Eu configurei o Wireshark para fazer lixões de 5MB, e eu peguei um pouco disso no ato esta manhã.

Você pode baixar a captura de pacotes . A diversão começou no pacote # 23968. Um pacote NBNS aparentemente mal formado é repetido várias vezes. No entanto, não é apenas um loop reto. Os endereços IP de origem (143.226.8.185) e de destino (143.226.44.79) permanecem os mesmos, mas o endereço MAC de origem é alterado. O primeiro pacote parece vir de algum dispositivo insignificante na rede e é enviado para um endereço multicast, 01: 00: 5e: 7f: ff: fa. Todos os pacotes depois vêm dos endereços MAC de nossos pontos de acesso sem fio da HP e são enviados para um endereço multicast diferente, 01: 00: 5e: 62: 2c: 4f.

Aqui está o primeiro pacote:

No.     Time        Source                Destination           Protocol Info
  23968 122.229240  143.226.8.185         143.226.44.79         NBNS     Unknown operation (10) unknown Illegal NetBIOS name (1st character not between A and Z in first-level encoding) unknown Illegal NetBIOS name (1st character not between A and Z in first-level encoding) unknown Illegal NetBIOS name (1st character not between A and Z in first-level encoding) unknown Illegal NetBIOS name (1st character not between A and Z in first-level encoding) unknown Illegal NetBIOS name (1st character not between A and Z in first-level encoding) unknown Illegal NetBIOS name (1st character not between A and Z in first-level encoding) unknown Illegal NetBIOS name (1st character not between A and Z in first-level encoding) unknown Illegal NetBIOS name (1st character not between A and Z in first-level encoding) unknown Illegal NetBIOS name (1st character not between A and Z in first-level encoding) unknown Illegal NetBIOS name (1st character not between A and Z in first-level encoding) unknown Illegal NetBIOS name (1st character not between A and Z in first-level encoding) unknown Illegal NetBIOS name (1st character not between A and Z in first-level encoding) unknown Illegal NetBIOS name (1st character not between A and Z in first-level encoding) unknown Illegal NetBIOS name (1st character not between A and Z in first-level encoding) unknown Illegal NetBIOS name (1st character not between A and Z in first-level encoding)[Malformed Packet]

Frame 23968 (1038 bytes on wire, 1038 bytes captured)
    Arrival Time: Sep 15, 2010 08:32:44.329966000
    [Time delta from previous captured frame: 0.004744000 seconds]
    [Time delta from previous displayed frame: 0.004744000 seconds]
    [Time since reference or first frame: 122.229240000 seconds]
    Frame Number: 23968
    Frame Length: 1038 bytes
    Capture Length: 1038 bytes
    [Frame is marked: True]
    [Protocols in frame: eth:ip:udp:nbns]
    [Coloring Rule Name: SMB]
    [Coloring Rule String: smb || nbss || nbns || nbipx || ipxsap || netbios]
Ethernet II, Src: IntelCor_d2:5e:6b (00:1f:3b:d2:5e:6b), Dst: IPv4mcast_7f:ff:fa (01:00:5e:7f:ff:fa)
    Destination: IPv4mcast_7f:ff:fa (01:00:5e:7f:ff:fa)
        Address: IPv4mcast_7f:ff:fa (01:00:5e:7f:ff:fa)
        .... ...1 .... .... .... .... = IG bit: Group address (multicast/broadcast)
        .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
    Source: IntelCor_d2:5e:6b (00:1f:3b:d2:5e:6b)
        Address: IntelCor_d2:5e:6b (00:1f:3b:d2:5e:6b)
        .... ...0 .... .... .... .... = IG bit: Individual address (unicast)
        .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
    Type: IP (0x0800)
    Trailer: 7773643D22687474703A2F2F736368656D61732E786D6C73...
    Frame check sequence: 0x6f70653e [incorrect, should be 0x30019938]
Internet Protocol, Src: 143.226.8.185 (143.226.8.185), Dst: 143.226.44.79 (143.226.44.79)
    Version: 4
    Header length: 20 bytes
    Differentiated Services Field: 0x00 (DSCP 0x00: Default; ECN: 0x00)
        0000 00.. = Differentiated Services Codepoint: Default (0x00)
        .... ..0. = ECN-Capable Transport (ECT): 0
        .... ...0 = ECN-CE: 0
    Total Length: 203
    Identification: 0x00d0 (208)
    Flags: 0x00
        0.. = Reserved bit: Not Set
        .0. = Don't fragment: Not Set
        ..0 = More fragments: Not Set
    Fragment offset: 0
    Time to live: 128
    Protocol: UDP (0x11)
    Header checksum: 0xe485 [correct]
        [Good: True]
        [Bad : False]
    Source: 143.226.8.185 (143.226.8.185)
    Destination: 143.226.44.79 (143.226.44.79)
User Datagram Protocol, Src Port: netbios-ns (137), Dst Port: netbios-ns (137)
    Source port: netbios-ns (137)
    Destination port: netbios-ns (137)
    Length: 183
    Checksum: 0x01db [validation disabled]
        [Good Checksum: False]
        [Bad Checksum: False]
NetBIOS Name Service
    Transaction ID: 0x4d2d
    Flags: 0x5345 (Unknown operation)
        0... .... .... .... = Response: Message is a query
        .101 0... .... .... = Opcode: Unknown (10)
        .... ..1. .... .... = Truncated: Message is truncated
        .... ...1 .... .... = Recursion desired: Do query recursively
        .... .... ...0 .... = Broadcast: Not a broadcast packet
    Questions: 16722
    Answer RRs: 17224
    Authority RRs: 8234
    Additional RRs: 8264
    Queries
        Illegal NetBIOS name (1st character not between A and Z in first-level encoding): type unknown, class Unknown (12081)
            Name: Illegal NetBIOS name (1st character not between A and Z in first-level encoding)
            Type: unknown
            Class: Unknown (12081)
        Illegal NetBIOS name (1st character not between A and Z in first-level encoding): type unknown, class Unknown (11631)
            Name: Illegal NetBIOS name (1st character not between A and Z in first-level encoding)
            Type: unknown
            Class: Unknown (11631)
        Illegal NetBIOS name (1st character not between A and Z in first-level encoding): type unknown, class Unknown (25701)
            Name: Illegal NetBIOS name (1st character not between A and Z in first-level encoding)
            Type: unknown
            Class: Unknown (25701)
        Illegal NetBIOS name (1st character not between A and Z in first-level encoding): type unknown, class Unknown (25914)
            Name: Illegal NetBIOS name (1st character not between A and Z in first-level encoding)
            Type: unknown
            Class: Unknown (25914)
        Illegal NetBIOS name (1st character not between A and Z in first-level encoding): type unknown, class Unknown (25970)
            Name: Illegal NetBIOS name (1st character not between A and Z in first-level encoding)
            Type: unknown
            Class: Unknown (25970)
        Illegal NetBIOS name (1st character not between A and Z in first-level encoding): type unknown, class Unknown (18273)
            Name: Illegal NetBIOS name (1st character not between A and Z in first-level encoding)
            Type: unknown
            Class: Unknown (18273)
        Illegal NetBIOS name (1st character not between A and Z in first-level encoding): type unknown, class Unknown (24953)
            Name: Illegal NetBIOS name (1st character not between A and Z in first-level encoding)
            Type: unknown
            Class: Unknown (24953)
        Illegal NetBIOS name (1st character not between A and Z in first-level encoding): type unknown, class Unknown (26979)
            Name: Illegal NetBIOS name (1st character not between A and Z in first-level encoding)
            Type: unknown
            Class: Unknown (26979)
        Illegal NetBIOS name (1st character not between A and Z in first-level encoding): type unknown, class Unknown (3338)
            Name: Illegal NetBIOS name (1st character not between A and Z in first-level encoding)
            Type: unknown
            Class: Unknown (3338)
        Illegal NetBIOS name (1st character not between A and Z in first-level encoding): type unknown, class Unknown (14882)
            Name: Illegal NetBIOS name (1st character not between A and Z in first-level encoding)
            Type: unknown
            Class: Unknown (14882)
        Illegal NetBIOS name (1st character not between A and Z in first-level encoding): type unknown, class Unknown (28730)
            Name: Illegal NetBIOS name (1st character not between A and Z in first-level encoding)
            Type: unknown
            Class: Unknown (28730)
        Illegal NetBIOS name (1st character not between A and Z in first-level encoding): type unknown, class Unknown (25455)
            Name: Illegal NetBIOS name (1st character not between A and Z in first-level encoding)
            Type: unknown
            Class: Unknown (25455)
        Illegal NetBIOS name (1st character not between A and Z in first-level encoding): type unknown, class Unknown (8717)
            Name: Illegal NetBIOS name (1st character not between A and Z in first-level encoding)
            Type: unknown
            Class: Unknown (8717)
        Illegal NetBIOS name (1st character not between A and Z in first-level encoding): type unknown, class Unknown (28513)
            Name: Illegal NetBIOS name (1st character not between A and Z in first-level encoding)
            Type: unknown
            Class: Unknown (28513)
        Illegal NetBIOS name (1st character not between A and Z in first-level encoding): type unknown, class Unknown (29287)
            Name: Illegal NetBIOS name (1st character not between A and Z in first-level encoding)
            Type: unknown
            Class: Unknown (29287)
[Malformed Packet: NBNS]
    [Expert Info (Error/Malformed): Malformed Packet (Exception occurred)]
        [Message: Malformed Packet (Exception occurred)]
        [Severity level: Error]
        [Group: Malformed]

Aqui está o próximo pacote:

No.     Time        Source                Destination           Protocol Info
  23969 122.229836  143.226.8.185         143.226.44.79         NBNS     Unknown operation (10) unknown Illegal NetBIOS name (1st character not between A and Z in first-level encoding) unknown Illegal NetBIOS name (1st character not between A and Z in first-level encoding) unknown Illegal NetBIOS name (1st character not between A and Z in first-level encoding) unknown Illegal NetBIOS name (1st character not between A and Z in first-level encoding) unknown Illegal NetBIOS name (1st character not between A and Z in first-level encoding) unknown Illegal NetBIOS name (1st character not between A and Z in first-level encoding) unknown Illegal NetBIOS name (1st character not between A and Z in first-level encoding) unknown Illegal NetBIOS name (1st character not between A and Z in first-level encoding) unknown Illegal NetBIOS name (1st character not between A and Z in first-level encoding) unknown Illegal NetBIOS name (1st character not between A and Z in first-level encoding) unknown Illegal NetBIOS name (1st character not between A and Z in first-level encoding) unknown Illegal NetBIOS name (1st character not between A and Z in first-level encoding) unknown Illegal NetBIOS name (1st character not between A and Z in first-level encoding) unknown Illegal NetBIOS name (1st character not between A and Z in first-level encoding) unknown Illegal NetBIOS name (1st character not between A and Z in first-level encoding)[Malformed Packet]

Frame 23969 (217 bytes on wire, 217 bytes captured)
    Arrival Time: Sep 15, 2010 08:32:44.330562000
    [Time delta from previous captured frame: 0.000596000 seconds]
    [Time delta from previous displayed frame: 0.000596000 seconds]
    [Time since reference or first frame: 122.229836000 seconds]
    Frame Number: 23969
    Frame Length: 217 bytes
    Capture Length: 217 bytes
    [Frame is marked: True]
    [Protocols in frame: eth:ip:udp:nbns]
    [Coloring Rule Name: SMB]
    [Coloring Rule String: smb || nbss || nbns || nbipx || ipxsap || netbios]
Ethernet II, Src: HewlettP_05:de:da (00:17:a4:05:de:da), Dst: IPv4mcast_62:2c:4f (01:00:5e:62:2c:4f)
    Destination: IPv4mcast_62:2c:4f (01:00:5e:62:2c:4f)
        Address: IPv4mcast_62:2c:4f (01:00:5e:62:2c:4f)
        .... ...1 .... .... .... .... = IG bit: Group address (multicast/broadcast)
        .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
    Source: HewlettP_05:de:da (00:17:a4:05:de:da)
        Address: HewlettP_05:de:da (00:17:a4:05:de:da)
        .... ...0 .... .... .... .... = IG bit: Individual address (unicast)
        .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
    Type: IP (0x0800)
Internet Protocol, Src: 143.226.8.185 (143.226.8.185), Dst: 143.226.44.79 (143.226.44.79)
    Version: 4
    Header length: 20 bytes
    Differentiated Services Field: 0x00 (DSCP 0x00: Default; ECN: 0x00)
        0000 00.. = Differentiated Services Codepoint: Default (0x00)
        .... ..0. = ECN-Capable Transport (ECT): 0
        .... ...0 = ECN-CE: 0
    Total Length: 203
    Identification: 0x00d0 (208)
    Flags: 0x00
        0.. = Reserved bit: Not Set
        .0. = Don't fragment: Not Set
        ..0 = More fragments: Not Set
    Fragment offset: 0
    Time to live: 127
    Protocol: UDP (0x11)
    Header checksum: 0xe585 [correct]
        [Good: True]
        [Bad : False]
    Source: 143.226.8.185 (143.226.8.185)
    Destination: 143.226.44.79 (143.226.44.79)
User Datagram Protocol, Src Port: netbios-ns (137), Dst Port: netbios-ns (137)
    Source port: netbios-ns (137)
    Destination port: netbios-ns (137)
    Length: 183
    Checksum: 0x01db [validation disabled]
        [Good Checksum: False]
        [Bad Checksum: False]
NetBIOS Name Service
    Transaction ID: 0x4d2d
    Flags: 0x5345 (Unknown operation)
        0... .... .... .... = Response: Message is a query
        .101 0... .... .... = Opcode: Unknown (10)
        .... ..1. .... .... = Truncated: Message is truncated
        .... ...1 .... .... = Recursion desired: Do query recursively
        .... .... ...0 .... = Broadcast: Not a broadcast packet
    Questions: 16722
    Answer RRs: 17224
    Authority RRs: 8234
    Additional RRs: 8264
    Queries
        Illegal NetBIOS name (1st character not between A and Z in first-level encoding): type unknown, class Unknown (12081)
            Name: Illegal NetBIOS name (1st character not between A and Z in first-level encoding)
            Type: unknown
            Class: Unknown (12081)
        Illegal NetBIOS name (1st character not between A and Z in first-level encoding): type unknown, class Unknown (11631)
            Name: Illegal NetBIOS name (1st character not between A and Z in first-level encoding)
            Type: unknown
            Class: Unknown (11631)
        Illegal NetBIOS name (1st character not between A and Z in first-level encoding): type unknown, class Unknown (25701)
            Name: Illegal NetBIOS name (1st character not between A and Z in first-level encoding)
            Type: unknown
            Class: Unknown (25701)
        Illegal NetBIOS name (1st character not between A and Z in first-level encoding): type unknown, class Unknown (25914)
            Name: Illegal NetBIOS name (1st character not between A and Z in first-level encoding)
            Type: unknown
            Class: Unknown (25914)
        Illegal NetBIOS name (1st character not between A and Z in first-level encoding): type unknown, class Unknown (25970)
            Name: Illegal NetBIOS name (1st character not between A and Z in first-level encoding)
            Type: unknown
            Class: Unknown (25970)
        Illegal NetBIOS name (1st character not between A and Z in first-level encoding): type unknown, class Unknown (18273)
            Name: Illegal NetBIOS name (1st character not between A and Z in first-level encoding)
            Type: unknown
            Class: Unknown (18273)
        Illegal NetBIOS name (1st character not between A and Z in first-level encoding): type unknown, class Unknown (24953)
            Name: Illegal NetBIOS name (1st character not between A and Z in first-level encoding)
            Type: unknown
            Class: Unknown (24953)
        Illegal NetBIOS name (1st character not between A and Z in first-level encoding): type unknown, class Unknown (26979)
            Name: Illegal NetBIOS name (1st character not between A and Z in first-level encoding)
            Type: unknown
            Class: Unknown (26979)
        Illegal NetBIOS name (1st character not between A and Z in first-level encoding): type unknown, class Unknown (3338)
            Name: Illegal NetBIOS name (1st character not between A and Z in first-level encoding)
            Type: unknown
            Class: Unknown (3338)
        Illegal NetBIOS name (1st character not between A and Z in first-level encoding): type unknown, class Unknown (14882)
            Name: Illegal NetBIOS name (1st character not between A and Z in first-level encoding)
            Type: unknown
            Class: Unknown (14882)
        Illegal NetBIOS name (1st character not between A and Z in first-level encoding): type unknown, class Unknown (28730)
            Name: Illegal NetBIOS name (1st character not between A and Z in first-level encoding)
            Type: unknown
            Class: Unknown (28730)
        Illegal NetBIOS name (1st character not between A and Z in first-level encoding): type unknown, class Unknown (25455)
            Name: Illegal NetBIOS name (1st character not between A and Z in first-level encoding)
            Type: unknown
            Class: Unknown (25455)
        Illegal NetBIOS name (1st character not between A and Z in first-level encoding): type unknown, class Unknown (8717)
            Name: Illegal NetBIOS name (1st character not between A and Z in first-level encoding)
            Type: unknown
            Class: Unknown (8717)
        Illegal NetBIOS name (1st character not between A and Z in first-level encoding): type unknown, class Unknown (28513)
            Name: Illegal NetBIOS name (1st character not between A and Z in first-level encoding)
            Type: unknown
            Class: Unknown (28513)
        Illegal NetBIOS name (1st character not between A and Z in first-level encoding): type unknown, class Unknown (29287)
            Name: Illegal NetBIOS name (1st character not between A and Z in first-level encoding)
            Type: unknown
            Class: Unknown (29287)
[Malformed Packet: NBNS]
    [Expert Info (Error/Malformed): Malformed Packet (Exception occurred)]
        [Message: Malformed Packet (Exception occurred)]
        [Severity level: Error]
        [Group: Malformed]

Louco, não? Se você observar a captura de pacotes, verá muito desse pacote repetido depois desse ponto. Ele continua depois disso, em vários outros arquivos.

Se isso fosse um loop, por que nossos APs estariam enviando este pacote? Esses APs estão espalhados por todo o nosso campus.

Um pouco mais de informação sobre a nossa rede ... É tudo plano. Ethernet reta corre para tudo, e nós temos um bloco de classe B de IPs. Nenhuma sub-rede Há um shaper de pacote, firewall e roteador entre nossa rede e nossa conexão WAN.

Por fim, se você vir este post e parecer familiar para você, isso é porque já publiquei um problema semelhante no passado que ainda não resolvemos, mas não o vi recentemente. Isso pode ser encontrado em comutadores HP enviando solicitações de ping multi-cast .

Muito obrigado pelo seu tempo!

Editar: O pacote 23968 está confirmado como o gatilho desta tempestade de multicast. Eu reproduzi esse pacote em nossa rede e o reiniciei novamente.

Editar / atualizar: fazendo mais algumas experiências. Eu peguei um dos nossos pontos de acesso HP e liguei-o diretamente ao meu PC. Nada mais ligado ao segmento. Se eu repetir o pacote inicial que estava causando os problemas para o AP, o AP responde uma vez. Se eu repetir a resposta do AP de volta ao AP, ele responde novamente. Cada vez que isso acontece, o TTL é reduzido. O que está acontecendo aqui é que os APs da rede ouvem inicialmente o pacote multicast quebrado do host e respondem a ele por meio de multicast. Cada AP ouve essas respostas de todos os outros APs e responde a eles. Cada AP ouve todas as respostas às respostas e responde a elas. Felizmente, ele reduz o TTL a cada vez, então a tempestade desaparece assim que o TTL atinge 0, e o pacote é eliminado. Agora tudo que preciso fazer é descobrir como parar esse comportamento!

O AP que tenho à minha frente é um HP Procruve 420 J8130B.

Editar (RESOLVIDO!): Depois de tentar aparentemente todas as definições de configuração no AP, ainda não consegui impedi-lo de retransmitir esses pacotes multicast. Eu descobri que não estávamos no firmware mais recente, então tentei atualizar, mas o problema persistiu. Então eu tentei rebaixar para a versão 2.1.7 de 29 de novembro de 2006. Não há problemas com este firmware! APs rodando 2.1.7 não retransmitem o pacote !!! Eu ainda estou esperando para descobrir como os dados de lixo eletrônico entraram na rede em primeiro lugar, mas o problema está resolvido por enquanto. Estamos fazendo um relatório de erros com a HP.

    

Answer 1

Em primeiro lugar, esses não são pacotes NBNS, são na verdade pacotes Plug-and-Play universais que tentam pesquisar dispositivos habilitados para "dispositivos de gateway da Internet". O UPNP-IGD usa multicast IPv4 para localizar esses dispositivos de borda. O protocolo, como é, diz que deve haver apenas um. O give-away está na carga útil do pacote:

M-SEARCH * HTTP/1.1
Host:239.255.255.250:1900
ST:urn:schemas-upnp-org:device:InternetGatewayDevice:1
Man:"ssdp:discover"
MX:3

.xmlsoap.org/ws/2004/08/addressing" xmlns:

O IGD é usado por alguns aplicativos para informar aos gateways NAT do consumidor como lidar com o NAT traversal para certos protocolos. Aplicativos de mensagens instantâneas e afins. Você pode fazer com que o Wireshark mostre melhor as coisas dizendo para decodificar o UDP / 137 como HTTP para essa captura.

Agora, por que isso está causando uma tempestade de multicast é a grande questão. Você está recebendo o mesmo tipo de pacote bem antes que a tempestade aconteça, mas eles estão sendo enviados corretamente para 239.255.255.250:1900. O pacote 23955, na verdade, vem do mesmo dispositivo que inicia a tempestade em 23968. No entanto, o pacote 23968 mostra o mesmo endereço MAC de destino (um indicando Multicast IPv4), mas tem um endereço IP de destino que está em seu bloco / 16 e NÃO deve seja multicast.

O pacote 23604 também é muito mal formado. Ele tem um cabeçalho Ethernet válido, mas o cabeçalho IP é estranhamente truncado e termina na mesma string UPNP-IGD que citei acima. O dispositivo que emitiu este pacote estranho e estranho é o mesmo dispositivo (bem, vem do mesmo endereço MAC, de qualquer forma) que o pacote 23968 que desencadeou a tempestade de multicast.

Minha melhor aposta neste momento é que o dispositivo em 00: 1F: 3B: D2: 5E: 6D seja adaptado de alguma maneira ou não esteja manipulando corretamente essas solicitações de pesquisa UPNP corretamente. O pacote 24717 mostra outra requisição M-SEARCH indo para 239.255.255.250:3702 que também vem do mesmo dispositivo. Endereço IP correto, porta incorreta (deve ser 1900).

Meu palpite é que a tempestade de multidifusão está sendo expulsa por um pacote com um endereço IP Unicast que chega com um endereço MAC multicast, e seus dispositivos de rede não lidam com esse caso inválido corretamente. Isso é sugestivo no fato de que os pacotes após o inicial reivindicam a origem do mesmo IP (143.226.8.185), mas o endereço MAC é todo diferente. Você tem um dispositivo ruim que conseguiu encontrar um bug na manipulação multicast / unicast de seus dispositivos de rede.

    

Answer 2

@Brad: Acabei de ver isso e estou imaginando se isso te dá uma ideia do problema.

link

    

Answer 3

Minha recomendação é abrir o gerenciador de tarefas no host que está enviando a transmissão e tentar fechar um para um todos os aplicativos que poderiam enviar algo para a rede e ao mesmo tempo olhar para os pacotes na rede (Wireshark ) para procurar o aplicativo que está dando problemas.