Solved

DOS attack

Posted on 2006-11-23
1
364 Views
Last Modified: 2012-05-05
What techniques are used to secure against DOS attacks, i.e. someone killing the signal over WI-FI?
0
Comment
Question by:pma111
1 Comment
 
LVL 32

Accepted Solution

by:
rsivanandan earned 125 total points
ID: 18002762
A stateful firewall which does proxy service would help you protect from the dos attacks.

In a denial of service attack, remote host(s) keep send the syn packet which basically is flooded a machine (usually a webserver kinda) and when its tcp/ip buffer runs over it breaks down.

So when you put in a firewall, what it does is it takes the hit on the firewall and saves the internal machines from doing it.

How it does?
1. An external host sends a syn packet.
2. Firewall responds with a syn+ack to the external host (at this point, the internal server doesn't even know that there is something going on like this).
3. If the external hosts sends an ack packet, then the firewall creates a new session by syn to ack to the internal server.
4. Then it connects them together so that the communication works.

So when somebody does the DOS attack by the syn, the firewall protects and it will let the connection go in only if the tcp/ip three way handshake is completed first with the external host.

Hope that explains.

Some products to look at www.juniper.com and www.cisco.com

Both have good firewalls and you can choose the product based on your requirements.

Cheers,
Rajesh
0

Featured Post

Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

Question has a verified solution.

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

You may have a outside contractor who comes in once a week or seasonal to do some work in your office but you only want to give him access to the programs and files he needs and keep privet all other documents and programs, can you do this on a loca…
Encryption for Business Encryption (https://en.wikipedia.org/wiki/Encryption) ensures the safety of our data when sending emails. In most cases, to read an encrypted email you must enter a secret key that will enable you to decrypt the email. T…
Sending a Secure fax is easy with eFax Corporate (http://www.enterprise.efax.com). First, Just open a new email message.  In the To field, type your recipient's fax number @efaxsend.com. You can even send a secure international fax — just include t…
A simple description of email encryption using a secure portal service. This is one of the choices offered by The Email Laundry for email encryption. The other choices are pdf encryption which creates an encrypted pdf of your email and any attachmen…

895 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

Need Help in Real-Time?

Connect with top rated Experts

16 Experts available now in Live!

Get 1:1 Help Now