Packet to SERVER (From router to SERVER) [ Source IP: 192.168.206.83, Destination IP: 192.168.206.66. the IPv4 address parameter is 192.168.206.83 and 192.168.1.83 ] ================ No. Time Source SPort Destination Protocol DPort Length Info DSCP 2 2017-01-06 08:52:49.662321 192.168.206.83 50001 192.168.206.66 SCTP 3868 98 INIT CS0 Frame 2: 98 bytes on wire (784 bits), 98 bytes captured (784 bits) Encapsulation type: Ethernet (1) Arrival Time: Jan 6, 2017 16:52:49.662321000 Malay Peninsula Standard Time [Time shift for this packet: 0.000000000 seconds] Epoch Time: 1483692769.662321000 seconds [Time delta from previous captured frame: 0.000179000 seconds] [Time delta from previous displayed frame: 0.000179000 seconds] [Time since reference or first frame: 0.000179000 seconds] Frame Number: 2 Frame Length: 98 bytes (784 bits) Capture Length: 98 bytes (784 bits) [Frame is marked: False] [Frame is ignored: False] [Protocols in frame: eth:ethertype:ip:sctp] Ethernet II, Src: Vmware_81:41:6b (00:50:56:81:41:6b), Dst: Vmware_81:a6:a3 (00:50:56:81:a6:a3) Destination: Vmware_81:a6:a3 (00:50:56:81:a6:a3) Address: Vmware_81:a6:a3 (00:50:56:81:a6:a3) .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default) .... ...0 .... .... .... .... = IG bit: Individual address (unicast) Source: Vmware_81:41:6b (00:50:56:81:41:6b) Address: Vmware_81:41:6b (00:50:56:81:41:6b) .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default) .... ...0 .... .... .... .... = IG bit: Individual address (unicast) Type: IPv4 (0x0800) Internet Protocol Version 4, Src: 192.168.206.83, Dst: 192.168.206.66 0100 .... = Version: 4 .... 0101 = Header Length: 20 bytes (5) Differentiated Services Field: 0x02 (DSCP: CS0, ECN: ECT(0)) 0000 00.. = Differentiated Services Codepoint: Default (0) .... ..10 = Explicit Congestion Notification: ECN-Capable Transport codepoint '10' (2) Total Length: 84 Identification: 0x0000 (0) Flags: 0x02 (Don't Fragment) 0... .... = Reserved bit: Not set .1.. .... = Don't fragment: Set ..0. .... = More fragments: Not set Fragment offset: 0 Time to live: 63 Protocol: SCTP (132) Header checksum: 0x1d3d [validation disabled] [Good: False] [Bad: False] Source: 192.168.206.83 Destination: 192.168.206.66 [Source GeoIP: Unknown] [Destination GeoIP: Unknown] Stream Control Transmission Protocol, Src Port: 50001 (50001), Dst Port: 3868 (3868) Source port: 50001 Destination port: 3868 Verification tag: 0x00000000 [Assocation index: 0] Checksum: 0xa9a86d3f (not verified) INIT chunk (Outbound streams: 3000, inbound streams: 3000) Chunk type: INIT (1) 0... .... = Bit: Stop processing of the packet .0.. .... = Bit: Do not report Chunk flags: 0x00 Chunk length: 52 Initiate tag: 0xe79f40cb Advertised receiver window credit (a_rwnd): 62464 Number of outbound streams: 3000 Number of inbound streams: 3000 Initial TSN: 176990880 IPv4 address parameter (Address: 192.168.206.83) Parameter type: IPv4 address (0x0005) 0... .... .... .... = Bit: Stop processing of chunk .0.. .... .... .... = Bit: Do not report Parameter length: 8 IP Version 4 address: 192.168.206.83 IPv4 address parameter (Address: 192.168.1.83) Parameter type: IPv4 address (0x0005) 0... .... .... .... = Bit: Stop processing of chunk .0.. .... .... .... = Bit: Do not report Parameter length: 8 IP Version 4 address: 192.168.1.83 Supported address types parameter (Supported types: IPv6, IPv4) Parameter type: Supported address types (0x000c) 0... .... .... .... = Bit: Stop processing of chunk .0.. .... .... .... = Bit: Do not report Parameter length: 8 Supported address type: IPv6 address (6) Supported address type: IPv4 address (5) ECN parameter Parameter type: ECN (0x8000) 1... .... .... .... = Bit: Skip parameter and continue processing of the chunk .0.. .... .... .... = Bit: Do not report Parameter length: 4 Forward TSN supported parameter Parameter type: Forward TSN supported (0xc000) 1... .... .... .... = Bit: Skip parameter and continue processing of the chunk .1.. .... .... .... = Bit: Do report Parameter length: 4 On Fri, Jan 13, 2017 at 11:27 AM, Sun Paul <paulrbk@xxxxxxxxx> wrote: > Hi All > > below is the packet trace in text format. > > > Packet received (From client to router) [ Source IP: 192.168.206.83, > Destination IP: 192.168.206.65. the IPv4 address parameter is > 192.168.206.83 and 192.168.1.83 ] > ====================== > > No. Time Source SPort > Destination Protocol DPort Length Info > DSCP > 1 2017-01-06 08:52:49.662142 192.168.206.83 50001 > 192.168.206.65 SCTP 3868 98 INIT > CS0 > > Frame 1: 98 bytes on wire (784 bits), 98 bytes captured (784 bits) > Encapsulation type: Ethernet (1) > Arrival Time: Jan 6, 2017 16:52:49.662142000 Malay Peninsula Standard Time > [Time shift for this packet: 0.000000000 seconds] > Epoch Time: 1483692769.662142000 seconds > [Time delta from previous captured frame: 0.000000000 seconds] > [Time delta from previous displayed frame: 0.000000000 seconds] > [Time since reference or first frame: 0.000000000 seconds] > Frame Number: 1 > Frame Length: 98 bytes (784 bits) > Capture Length: 98 bytes (784 bits) > [Frame is marked: False] > [Frame is ignored: False] > [Protocols in frame: eth:ethertype:ip:sctp] > Ethernet II, Src: RealtekU_54:81:87 (52:54:00:54:81:87), Dst: > Vmware_81:41:6b (00:50:56:81:41:6b) > Destination: Vmware_81:41:6b (00:50:56:81:41:6b) > Address: Vmware_81:41:6b (00:50:56:81:41:6b) > .... ..0. .... .... .... .... = LG bit: Globally unique > address (factory default) > .... ...0 .... .... .... .... = IG bit: Individual address (unicast) > Source: RealtekU_54:81:87 (52:54:00:54:81:87) > Address: RealtekU_54:81:87 (52:54:00:54:81:87) > .... ..1. .... .... .... .... = LG bit: Locally administered > address (this is NOT the factory default) > .... ...0 .... .... .... .... = IG bit: Individual address (unicast) > Type: IPv4 (0x0800) > Internet Protocol Version 4, Src: 192.168.206.83, Dst: 192.168.206.65 > 0100 .... = Version: 4 > .... 0101 = Header Length: 20 bytes (5) > Differentiated Services Field: 0x02 (DSCP: CS0, ECN: ECT(0)) > 0000 00.. = Differentiated Services Codepoint: Default (0) > .... ..10 = Explicit Congestion Notification: ECN-Capable > Transport codepoint '10' (2) > Total Length: 84 > Identification: 0x0000 (0) > Flags: 0x02 (Don't Fragment) > 0... .... = Reserved bit: Not set > .1.. .... = Don't fragment: Set > ..0. .... = More fragments: Not set > Fragment offset: 0 > Time to live: 64 > Protocol: SCTP (132) > Header checksum: 0x1c3e [validation disabled] > [Good: False] > [Bad: False] > Source: 192.168.206.83 > Destination: 192.168.206.65 > [Source GeoIP: Unknown] > [Destination GeoIP: Unknown] > Stream Control Transmission Protocol, Src Port: 50001 (50001), Dst > Port: 3868 (3868) > Source port: 50001 > Destination port: 3868 > Verification tag: 0x00000000 > [Assocation index: 0] > Checksum: 0xbaea49e5 (not verified) > INIT chunk (Outbound streams: 3000, inbound streams: 3000) > Chunk type: INIT (1) > 0... .... = Bit: Stop processing of the packet > .0.. .... = Bit: Do not report > Chunk flags: 0x00 > Chunk length: 52 > Initiate tag: 0xe79f40cb > Advertised receiver window credit (a_rwnd): 62464 > Number of outbound streams: 3000 > Number of inbound streams: 3000 > Initial TSN: 176990880 > IPv4 address parameter (Address: 192.168.206.83) > Parameter type: IPv4 address (0x0005) > 0... .... .... .... = Bit: Stop processing of chunk > .0.. .... .... .... = Bit: Do not report > Parameter length: 8 > IP Version 4 address: 192.168.206.83 > IPv4 address parameter (Address: 192.168.1.83) > Parameter type: IPv4 address (0x0005) > 0... .... .... .... = Bit: Stop processing of chunk > .0.. .... .... .... = Bit: Do not report > Parameter length: 8 > IP Version 4 address: 192.168.1.83 > Supported address types parameter (Supported types: IPv6, IPv4) > Parameter type: Supported address types (0x000c) > 0... .... .... .... = Bit: Stop processing of chunk > .0.. .... .... .... = Bit: Do not report > Parameter length: 8 > Supported address type: IPv6 address (6) > Supported address type: IPv4 address (5) > ECN parameter > Parameter type: ECN (0x8000) > 1... .... .... .... = Bit: Skip parameter and continue > processing of the chunk > .0.. .... .... .... = Bit: Do not report > Parameter length: 4 > Forward TSN supported parameter > Parameter type: Forward TSN supported (0xc000) > 1... .... .... .... = Bit: Skip parameter and continue > processing of the chunk > .1.. .... .... .... = Bit: Do report > Parameter length: 4 > > On Thu, Jan 12, 2017 at 6:53 PM, Michael Tuexen > <Michael.Tuexen@xxxxxxxxxxxxxxxxx> wrote: >>> On 12 Jan 2017, at 10:51, David Laight <David.Laight@xxxxxxxxxx> wrote: >>> >>> From: Sun Paul [mailto:paulrbk@xxxxxxxxx] >>>> Sent: 12 January 2017 09:31 >>>> Let me clear the understanding. below is the flow. >>>> >>>> 1. Client sends to Linux Router: 192.168.206.83 -> 192.168.206.56, >>>> 2. Linux router sends to SERVER where the source IP is unchanged: >>>> 192.168.206.83 -> 192.168.206.66 >>>> >>>> My question here is why SERVER cannot response this INIT chunk? >>> >>> Probably because the IP addresses embedded in the SCTP packet >>> don't match the ones in the IP header. >> I don't know if it matters on the linux implementation, but it shouldn't. >> An SCTP endpoint should consider the source address of the packet containing >> the INIT chunk and all the addresses listed in the INIT chunk as valid peer >> addresses. >> >> Could we get a .pcap file of the packet containing the INIT chunk captured >> at the server? I would expect an INIT-ACK or and ABORT. If that is not sent, >> the checksum was wrong or some kind of packet filtering is active on the >> server... >> >> Best regards >> Michael >>> >>> David >>> >>> N‹§ēæėrļ›yúčšØbēXŽķĮ§vØ^–)Þš{.nĮ+‰·ĨŠ{ąąËiŠ{ayš ʇڙë,j ĒfĢĒ·hš‹āzđ ŪwĨĒļ Ē·Ķj:+v‰ĻŠwčjØmķŸĸū Ŧ‘ęįzZ+ƒųšŽŠÝĒj" ú! >> -- To unsubscribe from this list: send the line "unsubscribe linux-sctp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html