Re: Problem on SCTP

[Sun Paul]

Packet received (From client)
======================

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 Tue, Jan 10, 2017 at 3:18 AM, Neil Horman <nhorman@xxxxxxxxxxxxx> wrote:
> On Tue, Jan 10, 2017 at 12:31:01AM +0800, Sun Paul wrote:
>> what kind of information do you need? the whole INIT packet?
>>
> That would be ideal.
>
>> On Mon, Jan 9, 2017 at 8:25 PM, Neil Horman <nhorman@xxxxxxxxxxxxx> wrote:
>> > On Mon, Jan 09, 2017 at 06:00:36PM +0800, Sun Paul wrote:
>> >> Hi
>> >>
>> >> the linux router just change the destination, so it can arrive on the
>> >> the SERVER.
>> >>
>> > Please post the relevant snippets from the client and server tcpdump
>> > operations
>> >
>> > Neil
>> >
>> >> On Mon, Jan 9, 2017 at 5:51 PM, David Laight <David.Laight@xxxxxxxxxx> wrote:
>> >> > From: Sun Paul
>> >> >> Sent: 09 January 2017 02:08
>> >> >
>> >> >> >> I am setting up a lab where the SCTP traffics from  client is passing
>> >> >> >> through a linux router before reaching to the SCTP server running
>> >> >> >> LKSCTP.
>> >> >> >>
>> >> >> >> The linux router did not change the source address of the client, so
>> >> >> >> when it arrived to the SCTP server, the source address is the oriingal
>> >> >> >> one.
>> >> >>
>> >> >> the INIT chunk arrive on the SERVER, but then no response. the
>> >> >> application that using in SERVER is the same as the other test.
>> >> >>
>> >> >> I noticed one thing in Ethernet frame of the incoming packet on the
>> >> >> SERVER compared to the one captured from the client is the LG bit on
>> >> >> the source address.
>> >> >>
>> >> >> The LG bit is set to 0 on the request packet received in the
>> >> >> SERVER,but it is 0 from the one originated on the client. willl it be
>> >> >> the root cause?
>> >> >
>> >> > Which addresses are you talking about, and what do you mean by the LG bit?
>> >> >
>> >> > Is your linux 'router' just routing (ie IP forwarding) or is it doing NAT?
>> >> > If it is changing the IP addresses then the addresses inside some SCTP
>> >> > chunks also need changing.
>> >> >
>> >> >         David
>> >> >
>> >>
>> --
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