Recently, some friends on the forum ask questions, such as the script recording the script recorded in the Winsock protocol, encountering the following error
Action.c (20): Error: CallConnect - Can't Assign Requested Address. Error Code: 10049.Action.c (20): Error: Timeout Expired While Trying to Connect. Error Code: 9017.
The 10049 here is an UDP protocol error. It is the script that does not synchronize with the server. What is the problem? Below I use an agreement to see what is wrong, SMTP protocol analysis:
1.SMTP works: First, email is transferred from the client to the server; the other is transferred from a server to another. 2.SMTP is a request / response protocol, command and response is based on ASCII text. And end with CR and LF. The response includes a three-digit code indicating the return state. 3.SMTP listening to the connection request in the TCP protocol No. 25 port 4. Connection and sending procedure:
a. Establish a TCP connection B. The client sends a helo command to identify the sender's own identity, and then the client sends a mail command server side hopes to respond with OK, indicating that you are ready to receive c. Client Send the RCPT command to identify the electronic Mail plan recipient, you can have multiple RCPT line server, indicating whether it is willing to accept mail D. negotiation end, send mail, send email with command data. End of F. End of the end of the input. This time, exit with the quit command.
5. Other two commands: vrfy --- is used to verify that the given user mailbox exists and receives more information about the user. EXPN --- is used to expand the mailing list.
6. Mail Routing Process: SMTP Server is routing email based on the domain name of the "Domain Name Service DNS. SMTP Server Route email based on MX records in DNS, the MX record registers domain names and related SMTP relay hosts, which belongs to this domain should be sent to the host.
If the SMTP server mail.withub.org receives a letter to PCL@withub.org
A.sendmail Request DNS Given the CNAME record of the host withub.org, if CNAME is sent again, then request mail.withub.org's CNAME record until not. b. Assume that is cname to Mail .withub.org, then sendmail request @ withub.org domain DNS to give MX records for mail.withub.org, Shmail MX 5 mail.withub.org10 shmail2.withub.org c. Sendmail finally requests DNS to give shmail.withub .org's A record, the IP address, if the return value is 1.2.3.4 d. Sendmail and 1.2.3.4 connection, transfer this to PCL@withub.org to 1.2.3.4 SMTP background program for this server
Here is a parsing process of the agreement, we have to look at it, then play back after using the LR recording script, the mail.withub.org returns Mail.withub.org to the client server to save this figure, most Comparison when playing next time. When you play back in the second time, the LR analog client sends a request. At this time, there is no new message on the server, and the return may be 0, and the return value saves this return value and the return value saved by the recorded script (that time may There are 3 new messages on the server, and the value returned by the server is 3), which is obvious that this value is dynamic. If your script is not modified, it must be returned to not succeed. Then the wrong information mentioned above, the same reason, we have to analyze what problems are, from the protocol, analyze from the system environment.
Solution, dynamic association
1. Use the same user to operate twice, then use the LR tool WDIFF to compare the script, find different places!
2. Automatically associate with LR
3. Hand-related, find the dynamic data to be replaced for replacement
