[Devil-linux-commit] build/scripts/configuration/help dcc.help, NONE, 1.1

[Heiko Z. <smi...@us...>]

Update of /cvsroot/devil-linux/build/scripts/configuration/help
In directory sc8-pr-cvs12.sourceforge.net:/tmp/cvs-serv25468/scripts/configuration/help

Added Files:
	dcc.help 
Log Message:
- updated razor-agents-2.84.tar.bz2
- updated kernel to 2.6.24.4
- updated pax-linux-2.6.24.4-test36.patch.bz2
- updated gradm-2.1.11-200803102037.tar.gz
- updated grsecurity-2.1.11-2.6.24.4-200803251800.patch.bz2
- updated Linux-PAM to 0.99.10.0
- su is now wokring again
- updated open-vm-tools to 2008.03.19-82724
- updated shadow 4.1.0
- added libdnet 1.11
- updated pam configurations files from BLFS book
- corrected permissions on su
and some code cleanup


--- NEW FILE: dcc.help ---
CONFIG_DCC
  The DCC or Distributed Checksum Clearinghouse is an anti-spam content filter 
  that runs on a variety of operating systems. As of the middle of 2007, it 
  involves millions of users, more than one hundred thousand client computer 
  systems, and more than 250 servers collecting and counting checksums related 
  to more than 300 million mail messages on week days. The counts can be used 
  by SMTP servers and mail user agents to detect and reject or filter spam or 
  unsolicited bulk mail. DCC servers exchange or "flood" common checksums. The 
  checksums include values that are constant across common variations in bulk 
  messages, including "personalizations."
  
  The idea of the DCC is that if mail recipients could compare the mail they 
  receive, they could recognize unsolicited bulk mail. A DCC server totals 
  reports of checksums of messages from clients and answers queries about the 
  total counts for checksums of mail messages. A DCC client reports the checksums 
  for a mail message to a server and is told the total number of recipients of 
  mail with each checksum. If one of the totals is higher than a threshold set by 
  the client and according to local whitelists the message is unsolicited, the 
  DCC client can log, discard, or reject the message.
  
  Because simplistic checksums of spam would not be effective, the main DCC 
  checksums are fuzzy and ignore aspects of messages. The fuzzy checksums are 
  changed as spam evolves. Since the DCC started being used in late 2000, the 
  fuzzy checksums have been modified several times.
  
  Unless used with isolated DCC servers and so losing much of its power, 
  the DCC causes some additional network traffic. However, the client-server 
  interaction for a mail message consists of exchanging a single pair of UDP/IP 
  datagrams of about 100 bytes. That is often less than the several pairs of 
  UDP/IP datagrams required for a single DNS query. SMTP servers make DNS queries 
  to check the envelope Mail_From value and often several more. As with the 
  Domain Name System, DCC servers should be placed near active clients to reduce 
  the DCC network costs. DCC servers exchange or flood reports of checksums, but 
  only the checksums of bulk mail. Since most mail is not bulk and only 
  representative checksums of bulk mail need to be exchanged, flooding checksums 
  among DCC servers involves a manageable amount of data.