Solved

stateful packet inspection -- relation to clients' computer security

Posted on 2009-07-02
2
270 Views
Last Modified: 2012-05-07
What does the "state" of a TCP/IP packet have to do with whether it is from a user-requested web site, or from a hacker trying to gain access to a client computer, with reagrd to the "stateful packet inspection" that presumably only hardware firewalls are capable of?
0
Comment
Question by:Casey Claassen
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
2 Comments
 
LVL 32

Accepted Solution

by:
rsivanandan earned 35 total points
ID: 24765085
To simply look at it,

If the packet coming from outside

1. Has SYN and ACK bit set then it means that the connection was indeed originated from the inside machine and that is why acknowledgment is coming.

2. After that every packet passed has sequence numbers which are math bound and has relation with the packet sent.

So keeping the state information helps find it.

Now if a hacker sends a reply packet with 'syn' and 'ack' bit set, the machine won't entertain it since it didn't originate that traffic at all.

Does that help?

Cheers,
Rajesh
0
 

Author Closing Comment

by:Casey Claassen
ID: 31599172
Yes, that does indeed help!
0

Featured Post

Enroll in June's Course of the Month

June’s Course of the Month is now available! Experts Exchange’s Premium Members, Team Accounts, and Qualified Experts have access to a complimentary course each month as part of their membership—an extra way to sharpen your skills and increase training.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Occasionally, we encounter connectivity issues that appear to be isolated to cable internet service.  The issues we typically encountered were reset errors within Internet Explorer when accessing web sites or continually dropped or failing VPN conne…
This article offers some helpful and general tips for safe browsing and online shopping. It offers simple and manageable procedures that help to ensure the safety of one's personal information and the security of any devices.
Come and listen to Percona CEO Peter Zaitsev discuss what’s new in Percona open source software, including Percona Server for MySQL (https://www.percona.com/software/mysql-database/percona-server) and MongoDB (https://www.percona.com/software/mongo-…
In this brief tutorial Pawel from AdRem Software explains how you can quickly find out which services are running on your network, or what are the IP addresses of servers responsible for each service. Software used is freeware NetCrunch Tools (https…

688 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question