TCP sequence number

hi!
I'm using a socket connection in my j2me application and i need to know the sequence number of every tcp packet that i receive, can i do that?
I was searching and i didn't find anything...
thanks!

http://www.ietf.org/rfc/rfc1889.txt and
http://today.java.net/pub/a/today/2006/08/22/experiments-in-streaming-java-me.html
infos here

Similar Messages

TCP Sequence number in Java domain

Hi,
Trying to get a platform unique number I thought about a combination between IP address and the local machine TCP sequence number.
Is there a way in Java to get the TCP sequence number?
Thanks,
-Michael

I don't think you can get down to that level. Java 1.6 might allow this when it is released.
There have been several posts today about determining "machine uniqueness". Usual solutions rely on platform-specific code to get some low-level network information (e.g. MAC address). The problem with this is
1) It currently relies on native calls (1.6 should have an API for MAC address though).
2) MAC addresses (local IP addresses, machine names, etc) can easily be changed/spoofed.
If you're using 1.5 and your code runs on the client-side, there is a pure-java fix you can do. You can generate a java.util.UUID for each machine when your software first runs, then store this value using the Preferences API. This number will persist until the OS is wiped.

How to remove "TCP Sequence Number Approximation Based Denial of Service" vulnrability ???

Hi Friends,
In our weekly security scan , following vulnrability has been detected "TCP Sequence Number Approximation Based Denial of Service" . could you please any one let us know , hot to remove or mitigate this vulnrability ???
Thanks!

Hello,
Please provide more details, specifically the 'port(s)' involved, the target service if known, the scanner in question, the version of ESXi scanned.
I.e. all ports, general, Nessus, ESXi 5.x
Best regards,
Edward L. Haletky
VMware Communities User Moderator, VMware vExpert 2009, 2010, 2011,2012,2013,2014
Author of the books 'VMWare ESX and ESXi in the Enterprise: Planning Deployment Virtualization Servers', Copyright 2011 Pearson Education. 'VMware vSphere and Virtual Infrastructure Security: Securing the Virtual Environment', Copyright 2009 Pearson Education.
Virtualization and Cloud Security Analyst: The Virtualization Practice, LLC -- vSphere Upgrade Saga -- Virtualization Security Round Table Podcast

Is there a patch for MS05-019 TCP Sequence Number Approximation Vulnerability remediation on Server 2008 R2!!!

I see the patch for all platforms except Server 2008 R2. Is there one?
http://www.microsoft.com/technet/security/bulletin/MS05-019.mspx
Affected Software:
Microsoft Windows 2000 Service Pack 3 and Microsoft Windows 2000 Service Pack 4 – Download the update
Microsoft Windows XP Service Pack 1 and Microsoft Windows XP Service Pack 2 – Download the update
Microsoft Windows XP 64-Bit Edition Service Pack 1 (Itanium) – Download the update
Microsoft Windows XP 64-Bit Edition Version 2003 (Itanium) – Download the update
Microsoft Windows Server 2003 – Download the update
Microsoft Windows Server 2003 for Itanium-based Systems – Download the update
Microsoft Windows 98, Microsoft Windows 98 Second Edition (SE), and Microsoft Windows Millennium Edition (ME) – Review the FAQ section of this bulletin for details about these operating systems.
Non-Affected Software:
Microsoft Windows Server 2003 Service Pack 1
Microsoft Windows Server 2003 with SP1 for Itanium-based Systems
Microsoft Windows Server 2003 x64 Edition
Microsoft Windows XP Professional x64 Edition

Hi Rodney,
Thanks for posting here.
Hotfix
893066 is the patch that will fix issues for only Windows server 2003/XP base operation system .
Are you encountering any issue on windows server 2008 R2? If so,
could you discuss that in detail ?
http://blogs.technet.com/b/networking/archive/tags/windows+server+2008+r2/
Thanks.
Tiger Li
Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Reading or changing sequence number in TCP packets

I don't know wether this is feasible,But you're my last chance to figure out something else.Can i read the sequence number that comes inside the TCP header in the incomming packets?This sound illogical but since there is a method for getting the IP of the sender(And that IP exits in the IP header Network layer i),then the sequence number (TCP header inside the Transport layer)must exits in the packet.Can i read it?
-And an even more illogical question? can i change that sequence number or the acknowlege number to form a new packet ? Its like converting a packet to and from a packet object to a string of bits ?
I know excatly where the sequence and acknowledge numbers are located (after how many bits) inside the TCP header?

ejp wrote:
first off I'm wanna appply this to javame application and jpcap have some native code i dunno how to use it on a cell phone.You cant.You can migrate the code to work on a mobile phone, in theory. This is unlikely to be worth it even if you succeed.
I was thinking if i can change the acknowledge numberYou can't.Like sticking your hand in a blender. Its simpler to say you can't but I say you shouldn't want to.
i can order the server i'm connected to to send the data from a specific byte no sequentially.Use a protocol that already understands that. HTTP and FTP spring to mind.There are existing protocols for this which work and your phone is likely to support HTTP with XHTML basic already.
-Drop this packet and then form another packet with the same info as if it were formed automatically except replaciong the acknolwedge number with the size of my buffered data + 1.TCP/IP will never let this work even if you could do it, which you can't. You cannot skip data this way. This is not what acknowledgements and sequence numbers are for.
I also know that some protocols support requesting files from a specific byte(like HTTP) but i wanna do it inside the network layer not the application layerWhy?You prefer the blender, I see.

TCP Sequence/Acknowledgement numbers

Hello everyone,
Please excuse me if this question is somewhat rudimentary, but I was as much looking for reassurance as anything else.
As I understand TCP sequence numbers and Acknowledgments, in a nutshell it's case that:
A Sequence number is sent from the host and is total number of bytes sent UP to this point, during the conversation, not including the current payload
The acknowledgement number would be the total number of bytes recevied by the destination, FROM the sender, plus one (i.e. the one being the next byte it expects to get).
Assuming this is right, I am somewhat confused by the following explanation, taken from this article (page 2):
https://www.novell.com/connectionmagazine/2001/05/sequence51.pdf
Explanation goes:
Host 1 ———>
Sequence number 1 with 9 bytes of data
Acknowledgment number field = 100
<——— Host 2
Sequence number 100 with no data (ACK)
Acknowledgment number field = 10 (in 1 + 9 bytes of data)
Host 1 ———>
Sequence number 10 with 5 bytes of data
Acknowledgment number field = 100
<——— Host 2
Sequence number 100 with no data (ACK)
Acknowledgment number field = 15 (in 10 + 5 bytes of data)
<——— Host 2
Sequence number 100 with 20 bytes of data
Acknowledgment number field = 15
Host 1: ———->
Sequence number 15 with no data (ACK)
Acknowledgment number field = 120 (in 100 + 20 bytes of
data)
If you would be so kind, I'm sort of looking for some confirmation that, in a nutshell, my appraisal as right, and also that the above explanation between Hosts 1 and 2 is a little confusing.
As a side note, I believe only the SYN and FIN flags actually count as payload data, and the article above begins at Byte 1 but makes no mention of SYN.
Thank you for reading.

Hi,
I believe the example is correct. Let's take it apart:
Host 1 ———>
Sequence number 1 with 9 bytes of data
Acknowledgment number field = 100
Host1 sends 9 bytes, numbering them from 1 (the Seq). The last byte is numbered as 9, and the subsequent byte will be numbered as 10 so this is what Host2 should acknowledge in its own segment. In addition, Host1 asks Host2 to continue sending data starting with the sequence number 100 (the Ack).
<——— Host 2
Sequence number 100 with no data (ACK)
Acknowledgment number field = 10 (in 1 + 9 bytes of data)
As requested by Host1, Host2 sends a segment with Seq=100. Because Host2 received the 9 bytes from Host1, it acknowledges them and tells Host1 to continue sending bytes starting with Seq=10.
Host 1 ———>
Sequence number 10 with 5 bytes of data
Acknowledgment number field = 100
Host1 continues sending data starting from Seq=10, and with 5 sent bytes, these are numbered 10-14. The next byte would be 15 which is the Ack number expected from Host2. Because Host2 did not send any data itself, Host1 just tells Host2 again to continue sending data, if any, starting with sequence number 100 (the Ack).
<——— Host 2
Sequence number 100 with no data (ACK)
Acknowledgment number field = 15 (in 10 + 5 bytes of data)
Host2 has received additional 5 bytes from Host1 numbered as 10-14, so it sends back a segment with Ack=15 (all up to 14 is received, continue with 15). As there are no data to be sent by Host2 at this point, the Seq=100 and the body is empty.
<——— Host 2
Sequence number 100 with 20 bytes of data
Acknowledgment number field = 15
Host2 suddenly has a data to send, and the bytes start with the sequence number of 100, so this is the Seq. Because no further bytes arrived from Host1 yet, we simply tell it to continue with byte 15 whenever Host1 has any bytes to send.
Host 1: ———->
Sequence number 15 with no data (ACK)
Acknowledgment number field = 120 (in 100 + 20 bytes of data)
Host1 has no data to send itself but it needs to acknowledge the received data from Host2. There were 20 bytes in the segment received from Host2, starting from 100 and ending with 119. The upcoming expected byte from Host2 is thus 120, hence the Ack field value. The Seq field value is 15, the upcoming byte number.
As a side note, I believe only the SYN and FIN flags actually count as payload data
This is true.
and the article above begins at Byte 1 but makes no mention of SYN.
In fact, the article above seems to omit the TCP session establishment phase, and simply starts showing the Seq and Ack values in the midst of an already established session.
Please feel welcome to ask further!
Best regards,
Peter

Debug Command For Sequence Number on ACL

Is their a way to run the dubug command to see what is happening on a specific sequence number within and ACL?
So for example if I have:
Extended IP access list 101
301 permit udp any eq ntp host 10.251.1.1 (12 matches)
310 permit udp host 10.214.1.2 host 10.251.1.3
320 permit tcp 10.0.0.0 0.255.255.255 host 10.251.134.81 eq www (12 matches)
I want to run a debug on sequence number 310 and that is it. So I can see the type of traffic and stuff hitting this speficic sequence number of ACL 106

try changing the acl line to:
310 permit udp host 10.214.1.2 host 10.251.1.3 log
add the global config command 'logging bufferred' and you can view the traffic hitting the logged acl line by using the command:
show log
hth
andy

How to pass the sequence number of current loop in a for loop in FPGA vi to the host

PCI-7830R
LV 8.2
What I was trying to do is to use multiple DIO to generate pulse at different sequence. Mode one is to automatically sweep from DIO1 to DIO20; mode 2 is several DIOs generate pulse simoutaneously. So I use a case structure to make the selection, in the mean time, I set up two for loop in each case so that I can use multiple pulse generations. For example, in scanning mode, if I set 2 exposures, it sweeps from 1 to 20 then do it again.
Then I need to get the loop sequence number, i of each scenario. So I put an indicator within the first loop, and create a local variable of it and put in the second one. Running the FPGA vi alone, I can see the indicator change in each case from 0 to N-1, N being the for loop time.But in the host vi, I tried to add this indicator as an element in the read/write invoke method, in the debugging mode, I could only see it directly jump to N-1 without all the changes I saw in FPGA vi.
Is it possible to get this number passed correctly from FPGA vi to the host vi? Thanks

Thanks for the reply Jared.
Excuse me if it looks incorrect, but I'm new to FPGA programming, so I would have to look into the FIFO you referred to. I used local variables because for one thing I have several different cases containing for loop in each of them, and I only want one indicator for the "i". If I put the indicator out of any for loop, it's only gonna show the last number which is N-1. For the other thing, it seems like property nodes are not allowed in FPGA vi. And by doing this, I can see the i number changing from 0 to N-1 in each case, well, in FPGA vi's front panel. But while I ran the host vi with everything, the indicator in host vi's front panel only showed the last number N-1. It may be the reason you said, it happened too fast before the indicator in host vi can catch it.
What I want to realize is to group the data I collect in host vi, for example, when I choose multiple exposure in each mode, and the FPGA runs 1 through 20 then do it again, I want the data stored in two groups using the loop sequence number as the seperator in file name. So it goes like 1-1, 2-1.......20-1; then 1-2, 2-2,.....20-2.

Need to query the database to get the last sequence number

Hi all
I am trying to get the last sequence number of the last row inserted into my Oracle database. Please could someone give me the SQL which would allow me to do this - using Oracle SQL Explorer I have confirmed that there is a sequence on the table which is called: XYZ_SEQ and the code for this is:
CREATE SEQUENCE "MY_USER_NAME"."XYZ_SEQ" MINVALUE 1 MAXVALUE 999999999999999999999999999 INCREMENT BY 1 START WITH 21 CACHE 20 NOORDER NOCYCLE ;
My Java application is inserting a row into my table and to insert a new row I need to have the last sequence inserted +1 so the new row can be added.
Any help would be much appreciated.

Hi,
Welcome to the forum!
If you are using a sequence just do (example):
INSERT INTO TABLE_NAME
   (COL1,
    COL2)
VALUES
   (SEQUENCE_NAME.NEXTVAL,
    OTHER_VALUE);to obtain (and use) the next number in the sequence when you are inserting.
If you have a sequence to use for a specific table, you should use it when your insert new data (no matter your are doing that: java application, procedure, etc). Doing this you avoid some problems when you have the sequence 'out of date' about the associated data.
Regards,
Edited by: Walter Fernández on Sep 19, 2009 10:08 AM
Edited by: Walter Fernández on Sep 19, 2009 10:10 AM

Portal Master-detail form how to auto assign detail record sequence number

Portal Master-detail form how to auto assign detail record sequence number.Please help me?

You can just read the following section
Can I specify a sequence number generator as the default value for a form column?
Yes. Enter the following in the "default value" field for the column:
#<schema name>.<sequence name>.nextval
where <schema name> is the name of the schema containing the sequence, and <sequence name> is the name of the sequence. The entry is preceded by a "#".
For example, if the schema name is "SCOTT", and the sequence name is "CUSTOMER_SEQ", the default value entry is:
#SCOTT.CUSTOMER_SEQ.NEXTVAL
same way you can do for master - detail form.
for more information on forms please refer the following URL.
http://otn.oracle.com/products/iportal/htdocs/portal_faq.htm#BuildingApplications
hope it helps.

File sequence number in a Flat file

Hi,
I am working on Idoc to file scenario wherein my output file will have a sequence number assigned to each level.
there are 4 levels and hence 4 sequence number to be genearted and its values should also have the same sequence number.
i am doing this just by using Counter function.
But when i am getting a multiple detail records, for each detail record(0040) level its keep incrementing.but it should have the same value what its level has.
for ex:
ALPHAMER AS2 E5 710 20114806124829 01.00
0000 00000000 20100102 V3.0 SORD CZ1
0010 00000001 76767 123 100 WER Constant BNG 560011 RAJ WERR     560011    BTM   X EN RT
0020 00000001 TYUIOP
0040 00000001 8765 6532 200 45 10 WE 20 AG
0040 00000002 8765 6532 200 45 10 WE 20 AG
0040 00000003 8765 6532 200 45 10 WE 20 AG
0040 00000004 8765 6532 200 45 10 WE 20 AG
9999 99999999
It has to be like this.
ALPHAMER AS2 E5 710 20114806124829 01.00
0000 00000000 20100102 V3.0 SORD CZ1
0010 00000001 76767 123 100 WER Constant BNG 560011 RAJ WERR     560011    BTM   X EN RT
0020 00000001 TYUIOP
0040 00000001 8765 6532 200 45 10 WE 20 AG
0040 00000001 8765 6532 200 45 10 WE 20 AG
0040 00000001 8765 6532 200 45 10 WE 20 AG
0040 00000001 8765 6532 200 45 10 WE 20 AG
9999 99999999
Can someone help me in achieving this.
Regards

Hi there,
Just to try out from a different view, the following case could be implemented if the pre-requiisites are satisfied:
Pre-requisites:
1) The element that carries a primary factor, let us say, '8765' from your example.
2) Functionally there is an element in your header item that relates the line items under it.
My understanding of your example:
1) Line items present for 00, 10, 40
2) Line item 30 absent in the series
Proposal:
Map source field (the one that is arelating factor, here the one that carries '8765') -> INDEX (start by 0, increment by 1) -> multiply by one.
INDEX standard function property: Donot Reset for every context;
Srikanth Srinivasan
Edited by: Srikanth Srinivasan on Jan 10, 2011 11:02 AM

Error While Generating Sequence Number. Contact your system Administrator

Hi All,
I have developed a form to provide our client with 'an easy to fill' User Interface. This form will be used instead of the standard form present in Business Suite.
Some columns of the table, on which form is based, are getting populated via generation of sequence numbers.
Now the problem is, after deploying custom form developed by me in the instance, Standard form is showing this error
" Error While Generating the Sequence Number. Please contact the System Administrator "
I am unable to trace why this error had started appearing..
Any suggestions would be of great help...
Thanks in Advance,..

Forms version 6i,
Database version 9.2.0.6.0
Sequences which I am using are used there in Standard form also..
So evrytime i need to save the record, I am selecting NEXTVAL of it into
the respective item of the datablock..

How to populate sequence number automatically in fusion web application

Hi all,
I created simple fusion web application.
I created a form which has programid and remaining fields are there.
If i press save button program details will save in database.
here i am giving programid manually. but i need to generate a sequence number to programid automatically.
If i give program details and save for this program details one sequence number should be generate and save in databasePlease help me
Thanks,
raj

Here there are two methods given
1. Generating sequence number from the trigger
2. another one is from java class.
I tried two but i am not getting the sequence number.
In my application under model project i have programview.
i created CustomEntityEmpl java class.
I double clicked on programid in attributes window, given some sequence name in name field,given db sequence name as as value.
i mentioned name of sequence in Java class. but still it is asking a value when submiting the program details with out program id.
please help ASAP
Thanks
Nag

Sequence number in process order

Hi,
Kindly brief about usage of sequence number, which is in process order with example. Is this can be used for capacity leveling. If so how that can be done.
If one sequence number is assigned to multiple process orders means double entries, then what is the impact during capacity leveling based sequence number.
Is number range is maintained any where in SPRO for sequence number. If so where? Is there any possibility to maintain number range for sequence number if required?
Thanks & Regards,
N. Laxman

1.Seq. number in an order
Number that can be assigned to production orders or planned orders at the level of the task list header and is therefore valid for all the operations in an order.
The sequence number is used to sort the orders for the display on the planning table and to
form a dispatching sequence using the sort key.
3.

Batch rename with minimum numeber of digits in sequence number

I'm pretty sure I remember this working how I wanted in previous versions of Bridge, but at least since cs4, it has not worked as I would like. I've tried searching for an answer or a setting that I'm missing, but have come back empty-handed.
Here's my situation. Let's say I'm renaming 18 files. Each file has a sequence number. I want the sequence numeber for the first 9 to be one digit, and for the second nine to be 2 digits.
i.e. image_1.jpg, image_2.jgp, image_3.jpg...image_10.jpg, image_11.jpg...
The best way I've found that I can do this is to select all 18 images, and assign a 2-digit sequence number. Then, once that is complete, select the first 9 and repeat, but with a 1 digit number.
In the past, I could select all 18 images, and choose a 1 digit number, and after 9, it would switch to 10, instead of going back to zero. Is there still a way to do that? I know it's only one extra step, but that one extra step is actually kind of two, because each time I have to reset tho starting number back to 1 or 10, and switch the setting from 2-digits to 1-digit and back again. And I usually have to rename multiple groups of files at once, so it does add up. Granted, much better than renaming one at a time, but not as convenient as I feel it could be, and as it once was.
Am I missing something?
Thanks,
iLan

While I certainly can understand the way in which computers work, I also understand that in a program as complex as any of the components in Adobe's Creative Suite, there is most certainly a way to override the computer's numerical logic so that it can remove the initial "0" from a 2-digit number. Granted, that may not be possible in the current version of Bridge, theoretically it is "Possible". And I'm quite sure it functioned that way in previous versions, although I really don't know which version I was using when it worked that way. Maybe cs2?
As a developer, the whole reason for this question is to avoid having to create extra code in my applications to add an unnecessary "0" to digits 0-9 in any filenames of any files I want to load. Although it looks as though adobe changed the default behavior of the batch rename function, and removed (or in some peoples' minds improved) some functionality without an option to get it back.
Unfortunately for me anyways...
Thanks for the help,
ilan

TCP sequence number

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