Login or Register to Ask a Question and Join Our Community


IP Networking

Incomplete three way handshake

Login to Discuss or Reply to this Discussion in Our Community

 
Thread Tools Search this Thread
Special Forums IP Networking Incomplete three way handshake
# 1  
Old 11-23-2007
Incomplete three way handshake
I've got a strange problem with a single mail sender (it is one of
those large free mail providers). My mail server works well with
thousands of senders but not this one, so we have made a connection
dump and it seems that the three way handshake is not completed

15:55:59.177431 IP ServerA.44601 > ServerB.25: S
2660877349:2660877349(0) win 5840 <mss 1380,sackOK,timestamp
3138006451 0,nop,wscale 0>
15:55:59.177751 IP ServerB.25 > ServerA.44601: S
4129790087:4129790087(0) ack 2660877350 win 5792 <mss
1460,sackOK,timestamp 2017496649 3138006451,nop,wscale 2>
15:56:02.972255 IP ServerB.25 > ServerA.44601: S
4129790087:4129790087(0) ack 2660877350 win 5792 <mss
1460,sackOK,timestamp 2017497598 3138006451,nop,wscale 2>
15:56:02.986696 IP ServerA.44601 > ServerB.25: . ack 1 win 5792 <mss
1460,sackOK,timestamp 2017497598 3138006451,nop,wscale 2>
15:56:02.986740 IP ServerB.25 > ServerA.44601: . ack 1 win 5792
<nop,nop,timestamp 2017497601 3138006451>
15:56:08.972156 IP ServerB.25 > ServerA.44601: S
4129790087:4129790087(0) ack 2660877350 win 5792 <mss
1460,sackOK,timestamp 2017499098 3138006451,nop,wscale 2>
15:56:08.987170 IP ServerA.44601 > ServerB.25: . ack 1 win 5792 <mss
1460,sackOK,timestamp 2017499098 3138006451,nop,wscale 2>
15:56:08.987192 IP ServerB.25 > ServerA.44601: . ack 1 win 5792
<nop,nop,timestamp 2017499101 3138006451>
15:56:20.972071 IP ServerB.25 > ServerA.44601: S
4129790087:4129790087(0) ack 2660877350 win 5792 <mss
1460,sackOK,timestamp 2017502098 3138006451,nop,wscale 2>
15:56:20.986619 IP ServerA.44601 > ServerB.25: . ack 1 win 5792 <mss
1460,sackOK,timestamp 2017502098 3138006451,nop,wscale 2>
15:56:20.986672 IP ServerB.25 > ServerA.44601: . ack 1 win 5792
<nop,nop,timestamp 2017502101 3138006451>
15:56:45.175830 IP ServerB.25 > ServerA.44601: S
4129790087:4129790087(0) ack 2660877350 win 5792 <mss
1460,sackOK,timestamp 2017508149 3138006451,nop,wscale 2>
15:56:45.190617 IP ServerA.44601 > ServerB.25: . ack 1 win 5792 <mss
1460,sackOK,timestamp 2017508149 3138006451,nop,wscale 2>
15:56:45.190664 IP ServerB.25 > ServerA.44601: . ack 1 win 5792
<nop,nop,timestamp 2017508152 3138006451>
15:57:33.375347 IP ServerB.25 > ServerA.44601: S
4129790087:4129790087(0) ack 2660877350 win 5792 <mss
1460,sackOK,timestamp 2017520199 3138006451,nop,wscale 2>
15:57:33.389931 IP ServerA.44601 > ServerB.25: . ack 1 win 5792 <mss
1460,sackOK,timestamp 2017520199 3138006451,nop,wscale 2>
15:57:33.389981 IP ServerB.25 > ServerA.44601: . ack 1 win 5792
<nop,nop,timestamp 2017520202 3138006451>


Someone can give me some advice? What I see is simply a strange mss
size at the beginning of 1380 that is not very usual but I am not sure
if it is relevant or not.
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

Help with incomplete Code

Hello, Since i am new in shell scripting, i need some help from you guys. :rolleyes: I am trying to implement an automata that reflects the attached photo.. The main idea behind is to take an array of (0 & 1)s from the user and terminate it by "end". Then, the string is send to the function... (1 Reply)
Discussion started by: Geekie
1 Replies

2. UNIX for Dummies Questions & Answers

Copy operation incomplete

I am logged into AIX 6.1 as a root user. I tried copying about 190GB of data to a different folder. cp -R /u01/data/scope /CY/backup I got the message: cp: Requested a write of 4096 bytes, but wrote only 3584. When the copy operation completed, I checked the /CY/backup/scope folder and... (3 Replies)
Discussion started by: shoefiend
3 Replies

3. UNIX for Dummies Questions & Answers

No mail sending - Deferred: 403 4.7.0 TLS handshake failed

Please help! I am in urgent need of assistance. What started out as a small problem with IMAP folders not working seems to have spread. Our mail server, Scalix running on CentOS 5.5 isn't sending out any mail. There are now over 400 emails queued waiting to go out, all of which give the... (0 Replies)
Discussion started by: beckyboo
0 Replies

4. Shell Programming and Scripting

Incomplete last line

I need help with appending the last line to the file only if the last line is incomplete. I tried awk 1 filename > new_filename but it appends to every file and I only want to append to the file if the last line is incomplete (3 Replies)
Discussion started by: smee
3 Replies

5. Shell Programming and Scripting

script incomplete

#!/bin/bash DIR=/dir/$(date +%y%m) || mkdir "$DIR" for D in $@ # obtem os argumentos do cp /usr/home/backup if backup=null then mkdir backup done How can I complete that script, that's not value, can someone help me complete this... The point of the program is: - If the... (1 Reply)
Discussion started by: strshel
1 Replies

6. Shell Programming and Scripting

incomplete last line

How do I find through script if a contains "incomplete last line". If it does then only insert a new line character as:: echo "" >> filename.txt (4 Replies)
Discussion started by: PRKS
4 Replies

7. Solaris

handshake/connection errors

I'm running solaris openssl 097l and I upgraded to 098h. I see errors in the logs that seem like debugging errors that showed up, but seemed to happen in both versions I believe. I am using a certificate from another machine to test for this server. I believe the error messages generate when I... (4 Replies)
Discussion started by: csross
4 Replies

8. Solaris

How to ignore incomplete files

On Solaris, suppose there is a directory 'dir'. Log files of size approx 1MB are continuously being deposited here by scp command. I have a script that scans this dir every 5 mins and moves away the log files that have been deposited so far. How do I design my script so that I pick up *only*... (6 Replies)
Discussion started by: sentak
6 Replies

9. UNIX for Dummies Questions & Answers

windows linux handshake !!

hi i wanted to know how to read the status of RTS/CTS line using ioctl calls....i am programming using c/c++ and linux if someone can post a code snippet or suggest a book for the same...it will be very helpful.... 2. also i will like to know can a windows application and a rtos application... (1 Reply)
Discussion started by: nivea_jmd
1 Replies

10. Programming

Three way handshake

Hi , I am mukesh. i would like to know the procedure of 3 - way handshake. (1 Reply)
Discussion started by: mukeshmca2
1 Replies
Login or Register to Ask a Question