This page describes the issues involved in configuring
bridged Internet solutions.
Bridged Internet Connection
shows a point to multi-point (Cell) connection in which customer A and B
are connected using a bridged solution to the Internet via the ISP.
configuration is very simple and cost effective to establish and has a
number of advantages:
There is no
customer configuration required, simplifying installation and reducing
both installation and operational support costs.
does not require any local concentration equipment (router/proxy etc)
instead the ISP located proxy provides the outgoing translation (via a Proxy or NAT function) from a private IP address to one or more public
IP addresses. This configuration reduces Customer access costs and
removes a barrier to entry.
PC configuration (IP address, netmask, Default Gateway and DNS
addresses) can be supplied from a DHCP Server located at the ISP
making network wide configuration changes trivial.
and B are behind the Proxy/Firewall and invisible to the rest of the
disadvantages of this configuration are:
A and B are 'in-range' of each other then all traffic from A is copied
onto the LAN at B (and vice versa). There is a potential privacy
problem (but there is NO security problem).
If the DHCP
server is mal-configured then PCs at Customer A COULD directly address
and access PCs at Customer B and hence create a security risk. If the
DHCP server is correctly configured this problem does not exist.
If the ISP
LAN is badly configured then all network broadcast traffic visible at
the ISP Air-Frame will be copied to Customer locations A and B (this
easily stopped by use of a VLAN at the ISP or by using a standard dual
LAN connection at the proxy).
In the case of
Point to Point connections (or a multi-point connection where the
customers are not in range of each other) disadvantages 1 and 2 above do
NOT exist and a bridged connection is probably the most cost effective