Security and firewalls
It is a risky game to allow external access to LAN
But exactly this is what DynAccess is for ....
Please take a minute's time for your security.
For many years this was a topic which no-one spoke
about - computer crime via the internet. In the mid- to late 90s - at
the time of the boot-sector virus - the main point of attack for
"bad boys" (also known as hackers) was at first the file
system in Windows 95/98, which was often freely available to anyone.
However, for a few years now we have had to be concerned with Trojans
which can be caught via email or even when surfing the web.
Operating systems have security holes via which the computers can be
attacked, even when everything is correctly configured.
A system administrator
who doesn't give this
will someday be unpleasantly surprised..
But security has its price. There are diverse
solutions at vastly different prices for various levels of
The main thing is to keep the software you use up to date. In addition,
the use of a firewall is essential.
A very trivial firewall is offered by NAT routers which, due to
the technique used (IP masquerading), make external access to internal
LAN workstations impossible.
Some hardware-router suppliers (e.g.
have extended their products with real firewall functionality - for
example intruder detection.
Personal firewalls are software solutions which are installed on
the local workstation and are implemented in the TCP/IP stack such that
the entire data traffic is monitored. The user can now decide what
rights are given to which programs in order to establish a connection
from inside to outside. This functionality provides an advantage
compared to the NAT firewall of a hardware router.
A further group of firewalls are security-gateway appliances,
which in addition to the configuration of complex firewall rules also
offer proxy servers for diverse services such as SMTP and HTTP.
These appliances monitor the contents of the data transferred and block
if a virus, Trojan etc is recognised.
Inform yourself what risks can arise for you if you make LAN resources
available over the internet. Also inform yourself about techniques
which allow you to safely run servers on the internet. For example, VPN
was developed in order to be able to set up cheap and safe site networks
over the internet where, previously, dedicated permanent connections were
Keep in mind that there can never be 100% security. Suppliers of
professional systems will always offer you a maintenance contract - for
times are changing quickly. One must react quickly to new threats.
Automatic updates, not only of virus-scanner signatures, are
Overview: personal firewalls