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Should You Fire Your Firewall? 50

Gsurface writes "A lengthy article over at Flexbeta.net focuses on firewall applications and how well they perform as far as securing your system. Four typical firewall applications were tested including two routers, one being the Cisco 831 SOHO, which performed rather well. In total, nine security test were conducted to measure how well each firewall performed."
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Should You Fire Your Firewall?

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  • Very interesting, although I'ven never been much for hardware firewalls. I grab an old machine, load it up with Slackware 9.1, and custom-configure the netfilter/iptables rules. I's a lot more versitile, and it's not just a firewall. It can be expanded to run every server known to man, such as ssh for remote control, or FreeS/WAN, for VPN.
    • by nocomment ( 239368 ) on Wednesday March 10, 2004 @11:29PM (#8528926) Homepage Journal
      Same here. Most of my company firewalls are running OpenBSD with PF. There's 1 linux box that is getting replaced very soon. Typical setup is 4 or 5 nics, multiple NAT's yadda yadda. plus now that OpenBSD is giong to have CARP [openbsd.org] in 3.5, you will have an auto-failover with a maintained state to another machine. This plus transparent squid caching, allows us to have about 100 users per T-1 with no complaints.
      • by Futurepower(R) ( 558542 ) on Thursday March 11, 2004 @11:00AM (#8532147) Homepage

        This is just one more case where an excellent area of inquiry is ruined by the wording of a Slashdot article, and by people trying to show how much they know without saying anything that could actually be used by someone else.

        The article at Flexbeta should not be worded, "An In-depth Look at Firewalls", it should be "An In-depth Look at Small System Firewalls". Most single computers or small LANs have no servers.

        The parent post is considering an important issue for systems of 100 users. Systems that large are far out of the scope of the Flexbeta article.

        We need two Slashdot articles on firewalls, one for small systems, and one for more complex LANS.

        The Flexbeta article considered only Linksys (now owned by Cisco) and D-Link small system hardware firewalls. It did not consider Airlink Plus [airlinkplus.com] and Netgear [netgear.com].

        I got burned with poor technical support from Cisco. Also, Cisco stopped supporting its 675 router. I don't want to be involved with Cisco again, so Linksys is out, especially because of the confused Linksys web site. Cisco has an enormous conflict of interest. If Linksys sells good firewalls, it will mean Cisco sells fewer.

        So, which is the better hardware firewall, D-Link DI-604, or the Netgear RP614?
        • D-link makes very poor equipment, definatly Netgear anyday of the week (just make sure its not in the slick silver cases, those are made by a third party, not sure who and they suck). BTW cisco and linksys arn't even remotly in the same market, so its really not a conflict of interest.

          • Any more info about Netgear would be helpful.

            Cisco 675 modems competed directly with Netgear. Not sure what Cisco is doing now.

            If you know the market, I think you would be convinced that there are many cases where Cisco sales people are selling very expensive gear when a $50 Netgear box would do as well.

            A 50-person company whose employees occasionally browse the internet, that has no servers, and only sends business email doesn't need much.
        • I dont have any experience with the D-Link 604, but i used to have a 704P and it kept overheating, at which point i would get terrible ping and dialup speeds. I managed to get a couple more months out of it by adding some fans to the side, but when it did finally die, I couldnt touch it for a few minutes. I have a Netgear RP612v2 now, its been working perfectly with regard to both the firewall and the network. I would definately say netgear is the better choice. Lets not even get started on linksys, every
        • Cisco is great if you are buying the expensive stuff. You can still get the software updates for the old routers. The support has always been good as well. But like you say the support for the smaller boxes is pretty poor. It is not even just the low end stuff. I have been burned by "enterprise" access points as well. It seems end of life happens just a few months after the first production is finished.

          Even if Linksys is a sperate entity from Cisco I won't buy one. Linksys has always made crap. A local ISP
    • by Creepy Crawler ( 680178 ) on Wednesday March 10, 2004 @11:33PM (#8528950)
      Hardware firewalls are not meant for exquisite filtering or heavy duty VPN. What does make firewalls nice is that they have multiple ports (hence a router) and have a FULL bandwidth between any 2 channels.

      With your example, once that nice PCI bus gets saturated... Game Over. Too bad they dont make a 1 GBps card for the AGP slot
      • by nocomment ( 239368 ) on Wednesday March 10, 2004 @11:54PM (#8529077) Homepage Journal
        Hardware firewalls are not meant for exquisite filtering or heavy duty VPN. What does make firewalls nice is that they have multiple ports (hence a router) and have a FULL bandwidth between any 2 channels.

        I agree with you, to a point. For a medium sized network like mine [slashdot.org], where there are _no_ hubs except for the one at the firewall (so the snort [snort.org] box can listen) the switches will take care of keeping the bandwidth that the firewall actually hears to a minimum. The PCI bus can handle 127-ish MB/s nad 64 bit PCI can handle 508-ish. So unless you have a really high traffic system[1] this setup is not even noticable between a Cisco, or other heavy duty router.

        [1] I have a really high traffic FTP server on my DMZ that is accessed a lot from systems on one of my NAT's and from the internet. What I did was move this system (OBSD) in _front_ of the firewall, enable PF on the FTP server to firewall it. Then I added a 2nd NIC to the FTP server so it plugs directly into the LAN. This makes sure that almost _no_ traffic from that system actaully hits the firewall. If I didn't do this, the PCI bus, like you say, would slow things to a crawl.
    • by Micro$will ( 592938 ) on Wednesday March 10, 2004 @11:39PM (#8528993) Homepage Journal
      Actually most home cable/DSL routers run a small embedded Linux distro, though I've found most are less robust than my old Pentium. My friend has to restart his Linksys almost daily, while my machine (Red Hat 8.0 minimal install) has 200+ days uptime. I've never tested the Linksys, but my setup gets a thumbs up from Shields Up. [grc.com]
      • Actually most home cable/DSL routers run a small embedded Linux distro

        Linux isn't bad because the OS can't handle the job, but rather because they just don't have the really wide backplane like the Cisco's have. If you were able to get a linux box with a backplane like what cisco uses linux would be jsut as effective, albeit perhaps not as robust as IOS.
    • It's a good first line of defense for the home user, especially if you're getting tired of keeping up the necessary due diligence for a good sofware firewall. I went with hardware on my home LAN about a year ago, after running software for several years. In this case, I'd been running RedHat and their release strategy change left me unsure of how I wanted to maintain that system. Getting hardware for my front-line meant that I just had to keep the box running for my internal services, though I did feel it n
  • Crap (Score:4, Insightful)

    by Old Uncle Bill ( 574524 ) on Wednesday March 10, 2004 @11:29PM (#8528925) Journal
    Any review of security/firewalls using Gibson's crappy analysis tools is beyond flawed. I would take all of this review with a grain or two of salt.
  • The Shields Up! Test (Score:5, Interesting)

    by Radical Rad ( 138892 ) on Wednesday March 10, 2004 @11:31PM (#8528941) Homepage
    The D-Link router failed to stealth one port whiles the bare system shows how vulnerable we can be without a firewall.

    But the port it shows as closed is 113 which is sometimes needed to authenticate to ftp or web sites. The authors of the review are assuming that the best firewall stealths absolutely everything. But if a product completely protects your system why wouldn't that be good enough? Same for ZoneAlarm4 not stealthing several ports under Advanced Port Scanning.

    I like the way they bring up outbound filtering though. Most "personal" firewalls don't do anything with this.

    • (For reference port 113 is the 'ident' identification protocol. Anyone using this for serious authentication should be shot.)

      • Anyone using this for serious authentication should be shot.

        It's "taken outside and shot". We don't want them bleeding all that stupid blood on the carpeting, now do we?

      • by orthogonal ( 588627 ) on Thursday March 11, 2004 @06:09AM (#8530426) Journal
        For reference port 113 is the 'ident' identification protocol.

        For reference, it's used by sendmail.

        Before learning this firewall users who read their logs (me!) will have a paranoia induced moment or two when they notice their host/ISP apparently scanning their ports, and will be even more bemused when they notice the scanning follows a regular period matching the period of their email client's polling.

        Fun stuff!
    • Yeah, their comments about the D-Link and port 113 illustrate the basic nature of the review. It's very easy to configure the D-Link routers to stealth 113 if you really want to. Just use the advanced tab in the setup to create a virtual-server at an unassigned IP address in the router's 192.168.0.* range and shunt the port 113 traffic there.
      • Not only that, but as an owner of a DI-604 I'm comfortable with the results.

        Basically it says it doesn't adequately block outbound traffic (which I don't care to block) but does a great job of blocking incoming traffic.

        For the price, what more could you want? I bought it before I bought an XP box to put on my LAN. (Actually, before I bought the DI-604, I didn't have a LAN per se.)
    • I'm not sure about the DI-604, but I had an old DI-704 that would stealth 113 given the proper tweaks. I'm also surprised the 604 didn't show up to ICMP scans since I had to manually set mine to not reply.

      The Zone Alarm results are confusing too. I just installed the free version on a friends machine, but had to disable it temporarily because it blocked the outbound request to access my file server. I assume there are many options you can configure to secure any hardware or software firewall, but you nee
      • Re:The Shields Up! Test Re:The Shields Up! Test (Score:1) by Micro$will (592938) on Wednesday March 10, @08:54PM (#8529083) (http://www.vixenny.com/) I'm not sure about the DI-604, but I had an old DI-704 that would stealth 113 given the proper tweaks. I'm also surprised the 604 didn't show up to ICMP scans since I had to manually set mine to not reply. The Zone Alarm results are confusing too. I just installed the free version on a friends machine, but had to disable it temporarily because it blocked the
      • Why even bother with nmap? I set up Zonealarm myself to allow my other computers to access the network freely. It was a lot of hassle. It was also pretty stupid, so I uninstalled it. Don't a large number of ISPs have upstream firewalls anyway? I'm on Comcast, and I'm pretty sure that there is a firewall upstream. I've taken the ShieldsUP test(s) before, and I'm always stealth across the board (with 113 merely closed, of course).
        • by Micro$will ( 592938 ) on Thursday March 11, 2004 @12:30AM (#8529270) Homepage Journal
          Don't a large number of ISPs have upstream firewalls anyway? I'm on Comcast, and I'm pretty sure that there is a firewall upstream.

          A lot of ISPs block certain ports, but which ones? Where are they blocked? Are they blocked all the time, or only during peak hours? You may be safe from a Shields Up scan, but are you safe from the 3|337 hax0r down the street?

          Trusting my ISP to keep my computer secure is like trusting public transportation to be on time. If I *must* be somewhere at a certain time, I'd rather leave a little early or drive just in case.
  • For a long time, I had no firewall. Now I use ZoneAlarm. There is a really large number of thing I don't understand about firewall and while the article was an interresting reading, there is many thing I don't understand. Can somebody give me a little info about internet security?

    Leak
    --------------------
    As I understand it, a leak occur when a firewall don't block a connection that should be blocked. How can this append? This sound like a very basic fonctionnality of a firewall and a firewall failing this s
    • Re:asdfas (Score:4, Informative)

      by Ayanami Rei ( 621112 ) * <rayanami@@@gmail...com> on Thursday March 11, 2004 @02:43AM (#8529821) Journal

      Leak:
      1) Hardware firewalls _rarely_ block outbound traffic, so they implictly allow out (since they can't predict what you'll need).
      2) Internal software firewalls work by intercepting a request to send a packet if it matches a rule. If the rogue software actively looks for a way to bypass the filter (by talking directly to the network card itself and bypassing the operating system), then there is nothing that can stop it.

      Hence the all fail the leak test. That's to be expected. In general you cannot expect to be connected to the internet at all and NOT be _somewhat_ vulnerable about information being transmitted without your knowledge.

      Browser test:
      You're right. Firewalls shouldn't double as a content/URL filter. That's the job of an "application proxy". Many firewall vendors are functioning as both... which is fine for a consumer who doesn't know the difference.

      However, this is partially due to the fact that windows has this API called "NDIS".
      Firewalls are implemented by placing filters in the NDIS chain that check for incoming/outgoing IP addresses and stuff, and can process them. But the NDIS chain also allows you to intercept URLs and how they are parsed, control DNS lookup, and more. (This is a Windows-specific feature). So most firewall developers naturally decided to add URL/content filtering because it was an easy step from IP filtering, since they were using the same programming interfaces.
      It wasn't rocket science... it was right there in the programming manuals next to the other stuff. :-)

      Port scan:

      By default, ZoneAlarm is configured to allow ports 135-139 in (but ONLY for the "Local Zone", if they bothered to check) so you can use Windows File Sharing between computers. It's easily turned off making the computer invisible to everyone just like the rest of them.

      ZoneAlarm wanted to be friendlier to people who wanted to share files or printers inside their house.

      • I use a Siemens 2602. I could easily set up a Slack9.1 box to do the same thing, but the electricity consumption, noise, space and admin aren't worth it.

        Blocking outbound is an important feature. My kids run MS-Win boxen, and these are sure to get trojanned. One of the nastiest rather quietly acts as a spam relay. AOL (hardly authoritative) has claimed 1/3 of spam inbound is from DHCP broadband. So I'm a responsible netadmin and block outbound 25 from their machines. They get their mail via yahoo any

        • I could easily set up a Slack9.1 box to do the same thing, but the electricity consumption, noise, space and admin aren't worth it.

          Know the feeling!

          I'm running Smoothwall Express 2 (GNU/Linux components) on my old PC, which is a tad overkill to protect a couple of machines. It would probably serve a small department or a couple of labs pretty well; it has snort, squid and so on and has a ssl-secured web interface for admin. Nice interface, good logging and traffic graphs, enough facilities to make it p

  • YRO? (Score:5, Insightful)

    by winsk ( 117756 ) on Thursday March 11, 2004 @12:56AM (#8529390)
    Does this really belong in the Your Rights Online section?
  • TooLeaky test is BS (Score:5, Interesting)

    by VarmintCong ( 151154 ) on Thursday March 11, 2004 @04:07AM (#8530099)
    I decided to try some of these tests myself. When testing using TooLeaky, I got a notification that it sent the information to GRC.com and recieved information from GRC.com, even when I disabled my internet connection.

    Sounds like BS to me.
  • by Frennzy ( 730093 ) on Thursday March 11, 2004 @09:44AM (#8531371) Homepage
    In general, you should always use a dedicated device to filter incoming packets. Consider it 'first line' defense.

    Where things like ZoneAlarm and Kerio make a difference is that they filter outbound connections. Of particular note is that, if the user pays attention and doesn't randomly approve everything the software shows them, then a firewall application can not only block specific outbound ports, but it can maintain specific application+port rules. That way, rogue malware can't hijack commonly used ports, such as port 80. It also would prevent worms/viruses that use their own SMTP engine.

    Data security should always be a layered approach. Take care of different threats with different (appropriate) defenses.
  • by tanguyr ( 468371 ) <tanguyr+slashdot@gmail.com> on Thursday March 11, 2004 @01:09PM (#8533731) Homepage
    One of the questions that this discussion doesn't take into account is just how good does a personal firewall on a home computer have to be in order to be effective?

    It seems to me that you have to take the "threat level" into account: are you looking for a solution to keep you one hundred percent safe in the face of a dedicated attack by an expert opponent or do you just want to deter random port scanning dorks from malasia? If you're not a convenient victim and your neighbor runs vanilla windows XP, doesn't have a firewall, doesn't apply security patches and, hey while we're at it, surfs porn from dodgy russian sites all day... chances are you're safe enough... for now. /t
  • I don't trust the buggers. I am currently running one of my home pc's with Win98SE stock from cd only patch is i run IE6.(though I use Firebird) I have offered for people whom I know to be in security related feilds to "hack me". To this day no one has. Granted I know this doesn't mean it can not be done, anything is possible. I just happen to keep a tight reign on what programs I allow to communicate to the outside world. Scary stuff. I have no anti virus either, and have gotten only 2 virus infections ne
  • I take it these folks used only default settings rather than setting things up for maximum security. My DI-604 stealths port 113 just fine because I've set it up that way.

    So, basically, I can't tell anything from this "review." If it doesn't accurately portray one products capabilities, it may not accurately portray the capabilities of any of them.

In the long run, every program becomes rococco, and then rubble. -- Alan Perlis

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