nanog mailing list archives
RE: Only 5x IPv4 /8 remaining at IANA
From: "George Bonser" <gbonser () seven com>
Date: Mon, 18 Oct 2010 10:52:18 -0700
-----Original Message----- From: Owen DeLong [mailto:owen () delong com] Sent: Monday, October 18, 2010 9:25 AM To: George Bonser Cc: Henning Brauer; nanog () nanog org Subject: Re: Only 5x IPv4 /8 remaining at IANA Nobody is using dynamic nat pools to block inbound connections. Many people are using dynamic NAT on top of stateful inspection where stateful inspection blocks inbound connections. The good news is that stateful inspection doesn't go away in IPv6. It works just fine. All that goes away is the header mangling.
Exactly true but there are people out there who experience it as "dynamic nat prevents inbound connections". And the extent to which state is inspected varies widely on different gear (is it just looking for an ACK flag to determine an "established" connection or is it making sure that at least one packet has gone in the other direction first?). At least with dynamic (overload) NAT, a packet had to travel in the opposite (outbound) direction in order to establish the NAT in the first place. Then with an "established" acl, the two things give you fairly decent assurance that things went as planned but are still not a substitute for packet inspection.
It's really unfortunate that most people don't understand the distinction.
Concur.
IPv6 with SI is no less secure than IPv4 with SI+NAT.
Yup, the difference is going to be the extent to which the state is inspected in various gear. Again, I believe firewall vendors are going to see a windfall here. And to address your comment in an email subsequent to this one about accounting, I wholeheartedly agree. NAT can make it much more difficult to find what is causing a problem or even who is talking to whom.
Current thread:
- Re: Only 5x IPv4 /8 remaining at IANA, (continued)
- Re: Only 5x IPv4 /8 remaining at IANA Stephen D. Strowes (Oct 18)
- Re: Only 5x IPv4 /8 remaining at IANA Paul Thornton (Oct 18)
- Re: Only 5x IPv4 /8 remaining at IANA ML (Oct 18)
- Re: Only 5x IPv4 /8 remaining at IANA Curtis Maurand (Oct 18)
- Re: Only 5x IPv4 /8 remaining at IANA Owen DeLong (Oct 18)
- Re: Only 5x IPv4 /8 remaining at IANA Henning Brauer (Oct 18)
- Re: Only 5x IPv4 /8 remaining at IANA Jared Mauch (Oct 18)
- RE: Only 5x IPv4 /8 remaining at IANA George Bonser (Oct 18)
- Re: Only 5x IPv4 /8 remaining at IANA Owen DeLong (Oct 18)
- RE: Only 5x IPv4 /8 remaining at IANA Tony Hain (Oct 18)
- RE: Only 5x IPv4 /8 remaining at IANA George Bonser (Oct 18)
- Re: Only 5x IPv4 /8 remaining at IANA Owen DeLong (Oct 18)
- RE: Only 5x IPv4 /8 remaining at IANA George Bonser (Oct 18)
- Re: Only 5x IPv4 /8 remaining at IANA Mark Smith (Oct 19)
- Re: Only 5x IPv4 /8 remaining at IANA ML (Oct 18)
- Re: Only 5x IPv4 /8 remaining at IANA Valdis . Kletnieks (Oct 18)
- Re: Only 5x IPv4 /8 remaining at IANA Andrew Kirch (Oct 18)
- Re: Only 5x IPv4 /8 remaining at IANA ML (Oct 18)
- Re: Only 5x IPv4 /8 remaining at IANA Jens Link (Oct 19)
- Re: Only 5x IPv4 /8 remaining at IANA Valdis . Kletnieks (Oct 19)
- Re: Only 5x IPv4 /8 remaining at IANA David Freedman (Oct 19)
- Re: Only 5x IPv4 /8 remaining at IANA Matthew Walster (Oct 19)