On 9 Oct 97, bjm @
dk wrote about Single point of failure.:
> A couple of firewall products offer the ability to support multiple
> network interface cards. These products are often used in solutions
> where different kind of user groups, servers/services etc. are
> separated on different LAN-segments connected to the firewall. If a
> company uses this functionality on a firewall, they introduce a single
> point of failure which I think is often neglected or forgotten.
There are more single points of failure in any given network on any
given day than I think most care to admit. While this does not
negate your argument, These option are best weighed in a 'risk-analysis'.
You check your probable risks, improbable risks and
possible risks associated with a given network/network device. You
then take very specific and measurable steps to protect the device or
the network as a whole. Backup devices are ALWAYS a good thing, but
rarely financially feasible. If the probable winds up being a
directed attack or a high failure rate for the firewall then a backup
is in order. If not...? While I abhor the fact that finances
are sometimes an issue when planning/protecting your network I do
respect a calculated risk.
The short version of my philosophy...which is subject to change at
any moment without prior notice from the managment. ;-)
1. Sometimes you're better off setting up a link state routing protocol on
your backbone, adding a redundant link and adding access lists to each of
your routers (solving the lack of dynamic recovery on a failed state
2. The support for additional security features through the use of
`packet header extensions' provided by IPv6 (thus allowing every host
behind the gateway router to authenticate / deny incoming packets)
eliminates the 'all or nothing' philosophy of the firewall. To some
this is a more appetizing course of action. Specially since IPv6 is
Firewalls (no offense) be damned if I can have my cake and eat it too.
Egads....I wrote a book even. =-o
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