Re: Problem on SCTP
From: Sun Paul
Date: Thu Jan 12 2017 - 22:27:14 EST
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
>>
>> NâÂÄÃÄrÄâyÃÄÅÃbÄXÅÄÄÂvÃ^â)ÃÅ{.nÄ+âÂÄÅ{ÄÄÃiÅ{ayÅ ÄâÃâÃ,j ÂÄfÄÄÂhÅâÄzÄ ÅwÄÄÄ ÄÂÄj:+vâÄÅwÄjÃmÄÅÄÅ ÅâÄÄzZ+ÆÅÅÅÅÃÄj" Ã!
>