Je ne suis pas notre gars de réseau normal ... Je viens d'être rédigé pour aider à résoudre ce problème, alors soyez indulgent avec moi.
Nous avons un réseau assez important (~ 4000 appareils?) Composé principalement de matériel HP Procurve. De temps en temps au cours des dernières semaines, nous avons reçu des tempêtes de diffusion qui empêchent à peu près tout autre trafic d'être envoyé sur le réseau. J'ai installé Wireshark pour faire des décharges de 5 Mo, et j'ai attrapé une partie de cela dans la loi ce matin.
Vous pouvez télécharger la capture de paquets . Le plaisir a commencé au paquet # 23968. Un paquet NBNS apparemment mal formé est répété maintes et maintes fois. Cependant, ce n'est pas seulement une boucle droite. Les adresses IP source (143.226.8.185) et de destination (143.226.44.79) restent les mêmes, mais l'adresse MAC source change. Le premier paquet semble provenir d'un périphérique insignifiant sur le réseau et est envoyé à une adresse de multidiffusion, 01: 00: 5e: 7f: ff: fa. Tous les paquets après cela proviennent des adresses MAC de nos points d'accès sans fil HP et sont envoyés à une adresse de multidiffusion différente, 01: 00: 5e: 62: 2c: 4f.
Voici le premier paquet:
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]
Voici le prochain paquet:
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]
Fou, non? Si vous regardez à travers la capture de paquets, vous verrez une grande partie de ce paquet répété après ce point. Cela continue encore et encore, dans plusieurs autres fichiers.
S'il s'agissait d'une boucle, alors pourquoi seuls nos points d'accès enverraient-ils ce paquet? Ces points d'accès sont dispersés sur tout notre campus.
Un peu plus d'informations sur notre réseau ... Tout est plat. Ethernet droit fonctionne sur tout et nous avons un bloc d'adresses IP de classe B. Pas de sous-réseaux. Il existe un module de mise en forme des paquets, un pare-feu et un routeur entre notre réseau et notre connexion WAN.
Enfin, si vous voyez ce message et qu'il vous semble familier, c'est parce que j'ai publié un problème similaire dans le passé que nous n'avons pas encore résolu, mais que nous n'avons pas vu récemment. Cela peut être trouvé sur les commutateurs HP envoyant des requêtes ping multi-cast .
Merci beaucoup pour votre temps!
Edit: le paquet 23968 est confirmé pour être le déclencheur de cette tempête de multidiffusion. J'ai rejoué ce paquet dans notre réseau et l'ai encore lancé.
Modifier / mettre à jour:Faire plus d'expérimentation. J'ai pris l'un de nos points d'accès HP et je l'ai branché directement sur mon PC. Rien d'autre attaché au segment. Si je rejoue le paquet initial qui causait les problèmes à l'AP, l'AP répond une fois. Si je rejoue la réponse de l'AP à l'AP, il répond à nouveau. Chaque fois qu'il le fait, le TTL est abaissé. Ce qui se passe ici, c'est que les points d'accès sur le réseau entendent initialement le paquet de multidiffusion cassé de l'hôte et y répondent par multidiffusion. Chaque AP entend ces réponses de tous les autres AP et il leur répond. Chaque AP entend toutes les réponses aux réponses et les réponses à celles-ci. Heureusement, il abaisse le TTL à chaque fois, de sorte que la tempête disparaît dès que le TTL atteint 0 et que le paquet est tué. Il ne me reste plus qu'à trouver un moyen d'arrêter ce comportement!
L'AP que j'ai devant moi est un HP Procruve 420 J8130B.
Modifier (RESOLU!): Après avoir essayé apparemment tous les paramètres de configuration de l'AP, je n'ai toujours pas pu l'empêcher de retransmettre ces paquets de multidiffusion. J'ai découvert que nous n'étions pas sur le dernier firmware, j'ai donc essayé la mise à niveau, mais le problème a persisté. J'ai ensuite essayé de rétrograder vers la version 2.1.7 à partir du 29 novembre 2006. Aucun problème avec ce firmware! Les points d'accès exécutant 2.1.7 ne retransmettent pas le paquet !!! J'attends toujours de comprendre comment les données indésirables ont été transmises sur le réseau en premier lieu, mais le problème est résolu pour l'instant. Nous faisons un rapport de bogue avec HP.