Re: Using a Linksys router, should I also use Zonealarm?

From: Miha Pihler (
Date: 07/28/03

Date: Mon, 28 Jul 2003 09:55:52 +0200

Hi Mary,

yes VPN is sort of a breach in the firewall. The problem is you are using
public internet to access corporate network. If your PC is unprotected in
the internet someone might notice this and try and use your PC over the
internet to access corporate network.
In the "old days" when people used to use Dial-In instead of VPN you ware
protected by corporate Firewall -- since there was no public Internet
network involved to act as a connection to Corporate network..

NAT is Network Address Translation. It translates private IPs (e.g.
., or to public internet addresses. Private
IP is special range of IPs that is not routed on the internet.
Large companies and even at home we use private IPs to access internet. The
reason is at home we usually only get one IP from our ISP. In the company
where we have thousands of computers it would be a waste of IP numbers that
are already in shortage.
But we can only use private IPs on our private networks. We can't access
internet with this IPs. So here is where NAT comes in to play. It allows us
to access internet from our private network by translating our private IP
e.g. to e.g

NAT devices (e.g. your Linksys router) can also help a bit with security
since it hides our PCs. We can have e.g. 100 PCs on internal network that
are protected by Linksys router that has one public IP address assigned to
it. Even though it protects our network this protection is limited and
should not be used or mistaken as firewall functionality.

I don't like ZoneAlarm very much either. It is "too" difficult to set it up
compared to some other software personal firewalls. BlackIce is OK regarding
protection and setting up.

I hope I didn't complicate too much :-)

MCSA 2K, MCSE 2K, MCT, ...
"Mary" <> wrote in message
> Thanks Miha and Lanwench:
> I'm very clueless about this stuff. I just presumed that since the
> network is protected by a firewall, that once I was logged into it, I was
> behind the firewall too. But I think from what you say, my VPN connection
> acts as a kind of breach of their firewall making it easier for hackers to
> piggyback me as I connect to the corporate network.
> I searched through some old messages on these newsgroups and some posters
> implied that the Linsksys router I'm using acts as a firewall too. So
> where I came up with that notion. What is a NAT box?
> I will have a look at Blackice. Lanwench, why don't you recommend
> Mary
> "Lanwench [MVP - Exchange]"
> <> wrote in
> news:u0Wud8KVDHA.2068@TK2MSFTNGP11.phx.gbl...
> > Note that your Linksys model is not a firewall - it's just a router/NAT
> box.
> > Better than nothing, but not very hard for people to get through. You
> should
> > definitely use a software firewall product in addition to it, especially
> if
> > you're connecting to a corporate network via VPN - they probably won't
> want
> > someone hacking in through your insecure internet connection.
> >
> > ZoneAlarm isn't one of the best out there - I know BlackIce is good
> > It should work fine with your VPN; I've done this before successfully.
> >
> > Or get a hardware firewall (Linksys makes one; don't remember the name
> > offhand but it has an X in it and is about $130-$140 US).
> >
> > Mary wrote:
> > > I'm using a Linksys Router (BEFSR41) to connect two computers
> > > (dekstop and laptop) to my DSL modem. My desktop computer is running
> > > Windows XP and my laptop is running Windows ME. In the past, I used
> > > Zonealarm on the desktop computer. However, I unistalled it about a
> > > year ago -- I was having issues with some other software, I don't
> > > remember what, and a technician suggested that I get rid of
> > > Zonealarm. I work from home via a VPN connection, and I do remember I
> > > used to have some issues in running Zonealarm while connected by VPN.
> > > I'm guessing that the VPN connection would be providing me with
> > > protection from bad stuff anyway while it's running so maybe
> > > Zonealarm is overkill at those times, is it? But once I disconnect my
> > > VPN connection, would it be a good idea to use Zonealarm then, or is
> > > my router enough of a barrier between me and the internet? Thanks.
> >
> >