Not _firewalling_, but access limitation. Grandma can live with PNAT router - she do not need any firewall, if she do not grant external access to anything. She can live with Windows _default deny_ setting. If grandma have extra money, it is better to purchase anty-virus. Moreover. Just for _ghrandma_, it can be cheaper do nothing than to invest into security (bad thing for us, I know!) - because she lost '$0' in case of intrusion... It explains shidespread of modern viruses, spam-trojans etc (they cost '$0' to infected households in many cases). It is as Wireless access - my friend have secured access point, but when I tried, I could use unsecured access points of 2 his neighbourths. They know abouth insecurity - but they do not lost anything, so they do not want to spend $0.01 to improve it. And unfortunately, I can not blame them.
On Wed, Mar 17, 2004 at 08:54:57AM -0800, bill said something to the
effect of:
The best option I guess is to figure out how important it is for you to have a firewall,
_Everyone_ (network connected) should have a firewall. My grandma should have a firewall. Nicole, holding dominion over this business network and its critical infrastructure, should _definitely_ have a firewall. ;)
Why? When did the end2end nature of the Internet suddenly sprout these mutant bits of extra complexity that reduce the overall security of the 'net?
Two questions asked, Two answers are sufficent.
Nope. One will do it. The day the first remote exploit or condition, in protocol or application, that could potentially have given rise to such and exploit made it possible for a user not in your control to gain control of your box(en), firewalling became necessary. Then Internet is not exactly end-to-end beyond pure fundamentals; it's more end-to-many-ends. And the notion of "end-to-end" requires preservation of a connection between 2 consenting hosts, and preservation includes securement of that connection against destructive mechanisms, which includes the subversive techniques and intercetptions commonly associated with network security.
Denial of Service is as much a threat to availability and network functionality as is power outage if it occurs. Before this turns to a "you security freaks want to screw around with my network and don't care about availability..."
Firewalls are logical interventions, costing as little as some processor overhead. Dedicated appliances are only one deployment. Filters on routers also qualify as firewalls. Am I correct in understanding that you feel edge filtering is mutant lunacy and unnecessary complexity?
Regarding dedicated firewalls, please see Mr. Bellovin's previous post regarding appropriate and competent administration. The lack thereof presents the complication, not the countermeasure itself.
As for your assertion that firewalls "reduce the overall security of the 'net."...can you please elaborate on that, as well? Other factions might/do argue that it's the other team refusing to lock their doors at night that are perpetuating the flux of bad behavior as a close second to the ignorant and infected.
--ra
-- k. rachael treu, CISSP rara@navigo.com ..quis costodiet ipsos custodes?..
--bill