Possibly Off Topic: Firewalls

[Phillip Jones, C.E.T.]

John McGhie makes reference to Firewall.

I use a DSL modem and my ISP put a route or digital switch between
modem and my Ethernet connection computer. I also have in Sharing
Stealth Mode. Is it still necessary to use a Firewall?

 

[John McGhie]

Hi Phillip:

It is always necessary to use a Firewall these days if you have a computer
that is connected to an "Always on" Internet service such as DSL.

However, in your case, you probably don't need to do anything, because you
probably already are using a firewall: most home routers include a simple
hardware firewall in their mechanism. A hardware firewall is preferable
because there is no way round them

You would need to read the instructions to find out if yours does, but I
would be surprised if it doesn't.

On the other hand, if your router doesn't have one, your Mac operating
system also includes a very effective firewall. You can hop into the System
Preferences and turn it on. Read the Apple Help for more.

Cheers

John McGhie makes reference to Firewall.

I use a DSL modem and my ISP put a route or digital switch between
modem and my Ethernet connection computer. I also have in Sharing
Stealth Mode. Is it still necessary to use a Firewall?

This email is my business email -- Please do not email me about forum
matters unless you intend to pay!

--

John McGhie, Microsoft MVP (Word, Mac Word), Consultant Technical Writer,
McGhie Information Engineering Pty Ltd
Sydney, Australia. | Ph: +61 (0)4 1209 1410
+61 4 1209 1410, mailto:[email protected]

 

[Corentin Cras-Méneur]

On the other hand, if your router doesn't have one, your Mac operating
system also includes a very effective firewall. You can hop into the System
Preferences and turn it on. Read the Apple Help for more.

I have a firewall on my router, and I still keep the firewall on my Mac
active.
Actually I can't find any good reason not to leave it active.



Corentin

 

[Phillip Jones, C.E.T.]

The man from the ISP had to bring a CD and run software from the CD
then, he keyed in only information that he knew about his service. It's
set up using DHCP.

Doesn't setting up software firewall such as the Mac OS firewall make it
more complex updating web Browsers, and email Clients. I use SeaMonkey
and also has a setting for firewall as well.

I know on PC's I've heard on Various newsgroups for Mozilla products and
other if you updated such you had to go into fire wall and remove that
application from it them find it again to make the new version work.

 

[Corentin Cras-Méneur]

Doesn't setting up software firewall such as the Mac OS firewall make it
more complex updating web Browsers, and email Clients. I use SeaMonkey
and also has a setting for firewall as well.

Absolutely not.
You can chose between different options anyway, but what I'd do is as
the System to add applications I use to the exception rules and you're
fine.
You have to realize that there are two things actually described here:
- incoming traffic filtering (which is what the System does for you). In
this case, you block unwanted incoming traffic, like hackers trying to
get in your Mac.
- outgoing traffic filtering. For this you need a third party tool like
Little Snitch. This is to avoid having a nastyware on your Mac trying to
send spam, phone home, etc.
The system firewall doesn't do that.

I know on PC's I've heard on Various newsgroups for Mozilla products and
other if you updated such you had to go into fire wall and remove that
application from it them find it again to make the new version work.

Bad firewalls...

Corentin

 

[John McGhie]

Hi Phillip:

The presence of a DHCP server in your router makes it far more likely that
it already contains a firewall. They're on the same chip

Firewalls can be complex to set up in a large organisation, but domestic
firewalls are usually of the very simple "If I did not start this
conversation, I am not going to listen to it" variety. Dead simple, zero
configuration needed, and only really smart attackers can get around it

Defeating such a firewall requires, time, knowledge, and persistence. Few
Internet script kiddies have any of those.

So my suggestion is: You almost certainly have a firewall, it's working,
and it will continue to do so if you don't try to change anything

Cheers

The man from the ISP had to bring a CD and run software from the CD
then, he keyed in only information that he knew about his service. It's
set up using DHCP.

Doesn't setting up software firewall such as the Mac OS firewall make it
more complex updating web Browsers, and email Clients. I use SeaMonkey
and also has a setting for firewall as well.

I know on PC's I've heard on Various newsgroups for Mozilla products and
other if you updated such you had to go into fire wall and remove that
application from it them find it again to make the new version work.

This email is my business email -- Please do not email me about forum
matters unless you intend to pay!

--

John McGhie, Microsoft MVP (Word, Mac Word), Consultant Technical Writer,
McGhie Information Engineering Pty Ltd
Sydney, Australia. | Ph: +61 (0)4 1209 1410
+61 4 1209 1410, mailto:[email protected]

 

[Phillip Jones, C.E.T.]

one last item and then we will let this thread die.

Anyone no what stealth mode is and is their any advantage to turning
just that on?

After this we will move on to more pressing topics.

 

[John McGhie]

Hi Phillip:

"Stealth Mode" disables the computer's responses to incoming traffic it is
not expecting.

If someone is trying to break in to your computer, they will normally begin
with a "Port scan". This scans all 65,000-odd "ports" on your connection,
looking to see if anything is there.

Normally, if you send traffic to a computer aimed at an application that is
not installed or not running, it should politely tell the caller "Sorry,
that number is not available, please try again later."

The hacker takes this as a sign that "Ah hah! There IS a computer at that
IP address". They can then unleash their whole bag of nasties to figure out
what kind of computer it is, what applications are running, and of those,
which ones would be easiest to break into.

If you put the Firewall in Stealth Mode, your computer simply does not
respond at all, to unwanted callers. So they have no indication that their
message was ever received, and thus, that there is in fact a computer there.
So they have no target to attack.

However: I would not turn it on. It can lead to unexpected problems with
applications such as Chat clients, that sit silently waiting for incoming
calls.

And if you are running Norton, it will very effectively deal with this
nonsense anyway. Norton contains a "Stateful packet inspector", a complex
Firewall that says not only "Did I start this conversation," but also "Was I
expecting that packet as a result of the conversation?"

This kind of complexity requires a lot more CPU power, which is one reason
the heavy-weight antivirus applications slow down the older computers. But
it's almost impossible to defeat it, even for the intelligence agencies of
nation states!

Cheers

one last item and then we will let this thread die.

Anyone no what stealth mode is and is their any advantage to turning
just that on?

After this we will move on to more pressing topics.

This email is my business email -- Please do not email me about forum
matters unless you intend to pay!

--

John McGhie, Microsoft MVP (Word, Mac Word), Consultant Technical Writer,
McGhie Information Engineering Pty Ltd
Sydney, Australia. | Ph: +61 (0)4 1209 1410
+61 4 1209 1410, mailto:[email protected]

 

[Phillip Jones, C.E.T.]

Thanks! Now we can let this thread die.

Hi Phillip:

"Stealth Mode" disables the computer's responses to incoming traffic it is
not expecting.

If someone is trying to break in to your computer, they will normally begin
with a "Port scan". This scans all 65,000-odd "ports" on your connection,
looking to see if anything is there.

Normally, if you send traffic to a computer aimed at an application that is
not installed or not running, it should politely tell the caller "Sorry,
that number is not available, please try again later."

The hacker takes this as a sign that "Ah hah! There IS a computer at that
IP address". They can then unleash their whole bag of nasties to figure out
what kind of computer it is, what applications are running, and of those,
which ones would be easiest to break into.

If you put the Firewall in Stealth Mode, your computer simply does not
respond at all, to unwanted callers. So they have no indication that their
message was ever received, and thus, that there is in fact a computer there.
So they have no target to attack.

However: I would not turn it on. It can lead to unexpected problems with
applications such as Chat clients, that sit silently waiting for incoming
calls.

And if you are running Norton, it will very effectively deal with this
nonsense anyway. Norton contains a "Stateful packet inspector", a complex
Firewall that says not only "Did I start this conversation," but also "Was I
expecting that packet as a result of the conversation?"

This kind of complexity requires a lot more CPU power, which is one reason
the heavy-weight antivirus applications slow down the older computers. But
it's almost impossible to defeat it, even for the intelligence agencies of
nation states!

Cheers




This email is my business email -- Please do not email me about forum
matters unless you intend to pay!

--

John McGhie, Microsoft MVP (Word, Mac Word), Consultant Technical Writer,
McGhie Information Engineering Pty Ltd
Sydney, Australia. | Ph: +61 (0)4 1209 1410
+61 4 1209 1410, mailto:[email protected]