101–110 of 606 posts
It's scary how much of this thread of supposed hackers comes from people who clearly don't understand the difference between a NAT and a firewall. NAT is not for security, it does not provide security. It is often bundled with a firewall. The firewall provides security. Firewall=\=NAT
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> Your own sources confirm what I'm saying. I don't see where they do. I see them talking almost exclusively about working around address depletion. Hell, look at Cisco's press release for its acquisition of Network Translation, Inc. [0] It's all about address depletion and resource efficiency; security is mentioned as an afterthought. I'll quote the relevant paragraphs (and leave in the line break mangling present i…
Read the Data Communications article they provided: PIX also increases network security. Since there's no way for anyone on the Internet to know which machine on the corporate network is using a Class C address at any given time, it's impossible to establish a telnet or FTP session with any particular device. And what about hosts that should be recognizable from the Internet, such as mail servers? These either can be…
What? It's a firewall that can do NAT. The PIX is clearly a security device. NAT is clearly an address-depletion-mitigation technique.
> Since there's no way for anyone on the Internet to know which machine on the corporate network is using a Class C address at any given time, it's impossible to establish a telnet or FTP session with any particular device.
Right. And you can achieve the exact same effect with a firewall on an edge router or on a host. I get that firewalls might have been much less common thirty-ish years ago and that doing packet filtering might have been pretty novel for many, leading folks to get confused when they encountered a combination firewall+NAT device.
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Read the Data Communications article they provided: PIX also increases network security. Since there's no way for anyone on the Internet to know which machine on the corporate network is using a Class C address at any given time, it's impossible to establish a telnet or FTP session with any particular device. And what about hosts that should be recognizable from the Internet, such as mail servers? These either can be…
> At some point you're going to have to find a way to argue that the Cisco PIX was not a security device... What? It's a firewall that can do NAT. The PIX is clearly a security device. NAT is clearly an address-depletion-mitigation technique. > Since there's no way for anyone on the Internet to know which machine on the corporate network is using a Class C address at any given time, it's impossible to establish a tel…
"You can achieve the same effect" doesn't mean anything in this discussion. If that's your argument, you've conceded the debate.
This is going to depend on the router and on IP distribution. My ISP does not give me an IPv6 address, only a single IPv6 which all my network devices have to NAT through. NAT is not intended to be a security feature, for sure, but it creates security as a side effect . If I start up a web server on one of my devices, I know that it is unreachable from the Internet unless I go out of my way to set a port forward on m…
> If each of my devices gets an Internet routable IPv6 address, at that point, that security-as-a-side-effect is not guaranteed unless my router has a default-deny firewall. I would hope that any routers would ship with that. They usually do, and they also ship with the most wonderful technology ever specified within a 67 MB compressed archive [0]: UPnP! Now your attacker's job is to convince you to initiate an outgo…
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Every router I’ve ever used has blocked incoming connections on v6 exactly the same as on v4. Really the only difference is you can have multiple devices on your network allowed to receive on the same port if you want.
> Every router I’ve ever used has blocked incoming connections on v6 exactly the same as on v4. A few years back my ISP didn't properly support prefix delegation, and the only way to get IPv6 to work was in "Passthrough" mode. My router (Asus ax86u) was really unclear about what passthrough mode meant, but I think that it might also disable the IPv6 firewall (I have read conflicting reports, and was never able to fin…
[0] https://www.snbforums.com/threads/ipv6-passthrough-disadvant...>
[1] https://github.com/Yamatohimemiya/6relayd>
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…and they did really guess an ipv6 address? Full scans of the ipv6 address space looks infeasible. Or did the sbc reach out to the internet thus having its address exposed? Otherwise just the huge amount of addresses should make ipv6 “more secure” imho.
I don't know how much impact this has in practice, but you do not need to scan the entirety of the ipv6 address space because you can just look at the IPs that are registered to known ISPs/ASs.
My ISP provides my house a /56 allocation. There are 4,722,366,482,869,645,213,696 addresses. I should have enough for a couple of years, at least.
I guess you could scan it. The IPs for most devices are chosen randomly within a /64 subnet, or they're based on MAC address, but they're not sequential by any means. A /64 is still 18,446,744,073,709,551,616 possible IPs.
It's scary how much of this thread of supposed hackers comes from people who clearly don't understand the difference between a NAT and a firewall. NAT is not for security, it does not provide security. It is often bundled with a firewall. The firewall provides security. Firewall=\=NAT
I think the confusion stems from the fact that my mom's laptop with its 192.168.0.43/24 v4 address is not routable except via NAT, and people believe (rightly or wrongly) that that confers a degree of security.
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> If each of my devices gets an Internet routable IPv6 address, at that point, that security-as-a-side-effect is not guaranteed unless my router has a default-deny firewall. I would hope that any routers would ship with that. They usually do, and they also ship with the most wonderful technology ever specified within a 67 MB compressed archive [0]: UPnP! Now your attacker's job is to convince you to initiate an outgo…
That's an entirely different attack scenario. To succeed at that attack, my computer would already need to be running malware. At that point, they've already won.
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> At some point you're going to have to find a way to argue that the Cisco PIX was not a security device... What? It's a firewall that can do NAT. The PIX is clearly a security device. NAT is clearly an address-depletion-mitigation technique. > Since there's no way for anyone on the Internet to know which machine on the corporate network is using a Class C address at any given time, it's impossible to establish a tel…
I'm not sure I can be any clearer about the fact that NAT is both a security feature and an address management feature. I feel like people who weren't practitioners are the time are trying to reason axiomatically that every feature fits into precisely one bucket, or that a security feature isn't a true security feature if it can be replaced by one or more other "cleaner" security features. None of that is true. Pract…
It's a security feature in the same way that a power-cut switch is a security feature. A power-cut switch's purpose is cut power to a machine so that it can -say- be safely worked on or relocated (or simply to not draw power when the machine's not in use), the machine also happens to be inaccessible while its power is cut.
Sure. It's not technically a lie to call a power-cut switch a security feature for most pieces of kit. I'd still laugh at the salesman that made the assertion. If I were feeling particularly cunty, I'd ask him if he injured himself from that great big stretch.
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I'm not sure I can be any clearer about the fact that NAT is both a security feature and an address management feature. I feel like people who weren't practitioners are the time are trying to reason axiomatically that every feature fits into precisely one bucket, or that a security feature isn't a true security feature if it can be replaced by one or more other "cleaner" security features. None of that is true. Pract…
Ah, I see what you're driving at. It's a security feature in the same way that a power-cut switch is a security feature. A power-cut switch's purpose is cut power to a machine so that it can -say- be safely worked on or relocated (or simply to not draw power when the machine's not in use), the machine also happens to be inaccessible while its power is cut. Sure. It's not technically a lie to call a power-cut switch a…
There are lots of security features I personally don't like either. I don't claim they're not security features; I say they're bad security features.