Anycast but for egress

Joe Maimon jmaimon at jmaimon.com
Thu Jul 29 20:58:34 UTC 2021


Vimal wrote:
> (Unsure if this is the right forum to ask this question, but here goes:)
>
> From what I understand, IP Anycast can be used to steer traffic into a 
> server that's close to the client.
>
> I am curious if anyone here has/encountered a setup where they use 
> anycast IP on their gateways... to have a predictable egress IP for 
> their traffic, regardless of where they are located?
>
> For example, a search engine crawler could in principle have the same 
> IP advertised all over the world, but it looks like they don't...  I 
> wonder why?
>
> -- 
> Vimal
>
Its definitely possible, but would need a layer of software (kernel 
mode) on all the anycast holders synchronizing state to ensure 
asymmetric replies/connections get forwarded/shifted to the correct host.

If the goals are worth that kind of effort is another question. And 
performance is likely to be "tricky".



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