> Inbox > Full Story
INSPECTION OF FIREWALLS
I read with interest the article 'Firewalls: Gatekeepers to
your Network' in the July 2001 issue of Network Magazine.
The article explained in simplistic terms what a Firewall
is. But in the section 'Selecting a Firewall' you stated that,
technically, just two types of firewalls exist (Network layer
and Application layer firewalls). But I am aware of another
technology called Stateful Inspection of Firewall technology
where both the network layer functions and the application
functions are integrated. With this technology packets are
intercepted at the network layer for best performance (as
in packet filters), but then data derived from all communications
layers is accessed and analyzed for improved security (compared
to layers 4-7 in application-layer gateways). This technology
then introduces a higher level of security by incorporating
communication and application derived state and context information
which is stored and updated dynamically. Please do comment
on this technology.
WHAT IS SNMP PROTOCOL?
Your article on Firewalls cleared many of my doubts. But I
need to know what is the SNMP protocol? Where is it used ?
Using Java can I develop this protocol ?
A: The Simple Network Management Protocol (SNMP) is
essentially a request-reply protocol running over UDP (ports
161 and 162), though TCP operation is possible. SNMP is an
asymmetric protocol, operating between a management station
(smart) and an agent (dumb). The agent is the device being
managed all its software has to do is implement a few simple
packet types and a generic get-or-set function on its MIB
variables. The management station presents the user interface.
Simple management stations can be built with UNIX command-line
utilities. More complex (and expensive) ones collect MIB data
over time and use GUIs to draw network maps. SNMP's packet
formats are described using Abstract Syntax Notation 1 (ASN.1),
one of ISO's "Open" protocols. ASN.1 basically fills
the role of XDR, but does so differently. ASN.1, like all
OSI standard documents, is not freely available on-line. For
more information on SNMP see the FAQ on the website: www.snmp.com/protocol/
HOOKED ON BLUETOOTH
I am unclear how the communication takes place in a Bluetooth
enabled transmitter and receiver. The 'hop' part of it remains
a mystery. Yes, I have been reading about Bluetooth and understand
that it uses spread spectrum, but I am foggy about the details.
Could you please suggest a text book that can guide me?
PUT IT MORE ACCURATELY
I head a company named Bluetooth for Federal Technology in
Bangalore, and would like to point out some mistakes in the
figure of the Bluetooth Stack (shown in the June 2001 issue
of Network Magazine).
1. Bluetooth has only one SDP and parallel to it there is
the TCS layer i.e. Telephony Control Protocol Specification
2. There is no specific layer for ACL and SCO. They are the
integral part of Baseband layer.
3. There is no specific layer like Bluetooth Radio. Actually
it is a dipole Antenna which is connected to Baseband layer.
4. RFCOMM instead of REFCOMM
You wrote about SCO but which layer will use SCO? For
that TCS is required, and you haven't wrote any thing about
Federal Technologies, Bangalore
WAP and JINI
I have read your article in Network Magazine. and you have
given the explanation about Bluetooth protocol stacks. But
there wasnt anything regarding JINI and WAP. You have
showed them as the part of Bluetooth protocol stack. I
would like to know regarding it.
Bluetooth and VLSI
I am a student of PICT VLSI Design Center, based in Pune.
As a part of the curriculum I want to work on Bluetooth as
the major project.I
have gone through latest information availabe on the Net.I
want to impliment security in Bluetooth in VHDL.Can
you to please suggest some functional block that can be designed
as an individual's project.
Seminar on Bluetooth
I am an enginneering student and am thinking of giving my
seminar on that. Can
you suggest some additional material on the topic.
am a regular reader of Network Magazine. The Linux articles
in May issue helped me a lot.I
am a final year student in computer branch in R.E.C., Durgapur,
Laxman Rao Kondeti
More info on Bluetooth
am a student from the IIT Madras. I have doubts regarding
how communication takes place in a Bluetooth enabled transmitter
am not able to understand the hop part of it. I
have read something about the Bluetooth. I just know that
it uses a spread spectrum. I do not have a clear idea of it.
you suggest some text book for this purpose?
I am doing computer science & engineering in Tamil Nadu.
Currently I am learning WAP. Can
suggest any additional reference for the same.
More on security
went through your feature on Firewalls. Can you cover some
additional stuff on security.As
per what I come to know of, firewalls alone arent sufficient
for protecting corporate networks. You
need to implemet additional protection for the same.Can
you eloberate on that.
IDS, Security policy, etc
I read your article on Firewalls and found it very informative.
you give more coverage to enterprise security especially on
IDS, encryption, etc.
More Basics and WorkShop Wisdom
am an engineering student doing my BE in Computer Science.
I find Network Magazine very informative, especially Basics
and WorkShop Wisdom very informative.Can
you carry more of these in your magazine.
am a regular reader of Network Magazine and read it from cover
you possibly carry tutorials for CCNA, MCSE, etc. These will
be handy since they will help in solving some of our concepts.
Need for security policy
picked up the Firewalls issue of Network Magazine and liked
it very much. I
want to implement a security policy for my company, and would
like to have more details.Can
you suggest any websites where I can find more information
on implementing a security policy.