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On 10/03/2013 03:42, Walter Dnes wrote: |
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> On Fri, Mar 08, 2013 at 07:41:13PM -0500, Michael Mol wrote |
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> |
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>> The trouble with NAT is that it destroys peer-to-peer protocols. The |
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>> first was FTP in Active mode. |
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> |
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> In its day, it was OK. Nowadays, we use passive mode. What's the |
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> problem? |
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> |
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>> SIP has been heavily damaged as well. Anyone who's used IRC is |
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>> familiar with the problems NAT introduces to DCC. |
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> |
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> Every ADSL router-modem I've run into recently has port-forwarding. |
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> |
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>> Anyone who's ever played video games online,... |
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> |
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> A *CLIENT* that can't operate from behind NAT is totally brain-dead. |
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> |
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>> or who's tried hosting a Teamspeak or Ventrillo server, has had NAT |
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>> get in their way as well. |
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> |
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> Port-forwarding. |
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All those examples you give are much like a bunch of home machines |
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sitting behind a NAT gateway onto the internet. That's actually OK and I |
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reckon that is the intended use of NAT. Personally, I'd prefer all of my |
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machines to have a public address but there's no chance in hell my |
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NetOps colleagues are giving me that with my DSL connection. |
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We have any years of experience now with consumer connections and the |
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users that use them, these guys mostly can't admin a machine to save |
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their lives, so NAT in their case is a good thing on balance. |
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The true evil of NAT comes about when some clown starts implementing it |
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on the network itself. I'm in city X, we have a large office in city Y, |
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and most of the traffic Y->X goes through a *router* doing NAT. No-one |
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knows anymore why this was originally done but we all know what it will |
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take to undo it. To get our backend systems to work for client in city Y |
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I have to put in the cursed "any any" firewall rules, and that sends our |
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Risk fellows ballistic for good reason. But I have no choice, the |
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network design essentially discarded all information as to who the |
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client is, so now I must allow all of them. |
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Any real-life network that grew organically over several years is always |
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going to be rife with examples of fuck ups like this, always done in the |
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name of expediency. I have lots of such examples, the above is only the |
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first that came to mind. |
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So whereas NAT behind a home router for IPv4 is good, in almost every |
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other usage I've seen it is bad and really just a case of a solution |
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used in places it never ever belonged. |
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-- |
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Alan McKinnon |
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alan.mckinnon@×××××.com |
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