nanog mailing list archives
Re: NAT on a Trident/Qumran(/or other?) equipped whitebox?
From: James Bensley <jwbensley () gmail com>
Date: Tue, 16 Oct 2018 15:05:55 +0100
On Mon, 15 Oct 2018 at 10:07, <adamv0025 () netconsultings com> wrote:
Interesting, but isn’t stateful tracking once again just swapping, but in this case port 123 in port 32123 out? So none of the chips you named below support swapping parts of L4 header and that part is actually done with SW assistance please? So for example the following: https://eos.arista.com/7150s-nat-practical-guide-source-nat-dynamic/#2Dynamic_Source_NATOverload_Many_to_one - wouldn’t be at line-rate please?
Hi Adam, NAT/PAT is an N:1 swapping (map) though so a state/translation table is required to correctly "swap" back the return traffic. MPLS for example is 1:1 mapping/action. NAT/PAT state tables tend to fill quickly so to aid with this we also have timers to time out the translations and free up space in the translation table, and also track e.g. TCP RST or TCP FIN to remove entries from the table, so it's not "just swapping". Cheers, James.
Current thread:
- NAT on a Trident/Qumran(/or other?) equipped whitebox? Jason Lixfeld (Oct 09)
- Re: NAT on a Trident/Qumran(/or other?) equipped whitebox? Edward Dore (Oct 09)
- Re: NAT on a Trident/Qumran(/or other?) equipped whitebox? Tim Jackson (Oct 09)
- Re: NAT on a Trident/Qumran(/or other?) equipped whitebox? Jason Lixfeld (Oct 09)
- Re: NAT on a Trident/Qumran(/or other?) equipped whitebox? Wes Felter (Oct 10)
- Re: NAT on a Trident/Qumran(/or other?) equipped whitebox? Paul Zugnoni (Oct 12)
- RE: NAT on a Trident/Qumran(/or other?) equipped whitebox? adamv0025 (Oct 15)
- Re: NAT on a Trident/Qumran(/or other?) equipped whitebox? James Bensley (Oct 16)
- Re: NAT on a Trident/Qumran(/or other?) equipped whitebox? Brandon Martin (Oct 16)
- Re: NAT on a Trident/Qumran(/or other?) equipped whitebox? joel jaeggli (Oct 16)
- Re: NAT on a Trident/Qumran(/or other?) equipped whitebox? Paul Zugnoni (Oct 16)
- Re: NAT on a Trident/Qumran(/or other?) equipped whitebox? Paul Zugnoni (Oct 12)
- Re: NAT on a Trident/Qumran(/or other?) equipped whitebox? Edward Dore (Oct 09)