I N S T A L L I N G C O M S I F T E R
User Guide |
ComSifter CS-8D Pro
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Overview
ComSifter is a standalone appliance that connects your internal LAN to the Internet while seamlessly offering
firewall and content filtering.
Internet Gateway
ComSifter is the gateway device from a private LAN to the public Internet. It is able to operate as a standard
router or in a Network Address Translation (NAT) mode. In the NAT mode, ComSifter converts internal IP
addresses to a public IP, effectively isolating your private network from the Internet.
Non-Stop Operation
Two ComSifter Non-Stop units, in conjunction with two Internet connections, offer a reliable Internet connection
for organizations that cannot afford any down time. A state-of-the-art failover-enabled DHCP server performs
IP/gateway-based load balancing while instructing client computers that there are two gateways to the Internet.
Each ComSifter performs a series of steps every five minutes to determine if a valid Internet connection is
available. If not, the ComSifter will shut down its LAN interface. This shutdown will trigger Dead Gateway
Detection on client computers using this gateway. Client computers will then switch to the other ComSifter.
This same process will occur if either ComSifter is lost due to a hardware failure.
Firewall
An industrial strength, rules-based stealth firewall is included in ComSifter. The firewall allows complete control
of all ports from the Internet to the LAN and from the LAN to the Internet. The resolution of the firewall is such
that a single port on a single computer on the LAN can be allowed to a single port on a single IP on the
Internet. The firewall can block internal port hopping programs, has log rate limiting, and does not over react to
Denial of Service attacks. Full logging of every transaction is available.
Filtering System
ComSifter CS-8D Pro incorporates eight individual filters. Each filter may be individually configured for the user
computers that access the filter. Additionally, a global filter allows configuration system wide.
When the user computer accesses a filter, two types of filtering are performed:
First, ComSifter compares the requested site with its blacklist to determine if the address has already
been deemed inappropriate. If the site is blacklisted, the user will receive a Denied Access Page, and
will not be able to view the site.
Second, if the site is not blacklisted, ComSifter will scan every word on the Internet page, using its
CSphrase Filtering Technology, looking for words that indicate inappropriate content. The context of
these words is analyzed to determine if the page should be blocked. This greatly reduces the number of
false positives while blocking those pages that are offensive. This feature accounts for ComSifter’s
remarkable accuracy.
If the content passes through both types of filtering, ComSifter allows the page to be loaded on the user’s
computer. If either of the filters disallow, a “Denied Access Denied” page is sent to the user’s computer. All this
is done in a fraction of a second, with no delay seen by the user.
Summary of Contents for CS-8D Pro
Page 1: ...ComSifter protect web users now User Guide Model CS 8D Pro Version March 26 2012 0326121500 ...
Page 153: ...F I L T E R S E T U P User Guide ComSifter CS 8D Pro 4 23 Figure 4 19 Modify Page RegEx ...
Page 194: ...U S E R S User Guide ComSifter CS 8D Pro 6 28 Figure 6 19 Windows Firewall ...
Page 215: ...U S E R S User Guide ComSifter CS 8D Pro 6 49 Figure 6 40 Add User ...
Page 219: ...U S E R S User Guide ComSifter CS 8D Pro 6 53 Figure 6 43 Add IP ...