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Is there a way I can give traffic over IPv6 a higher priority than traffic over IPv4?

Purpose is 2-fold: Promote IPv6, and be able to connect even when my server is swamped by IPv4 users.

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You almost certainly can't prioritize inbound traffic, unless you control the device that decides what inbound traffic to put on the wire. – David Schwartz Oct 5 '12 at 9:54

I have no experience with tc, but it appears that you can at least limit traffic based on specific markers set via iptables. If that works, you can then just limit IPv4 traffic to, say, 95% of your interface’s bandwidth by setting the appropriate marker in iptables, but not in ip6tables.

Further reading of the associated manpages probably would reveal more information :)

Regarding David Schwartz’ remark, I would like to point out that, provided traffic is TCP-based, appropriate delaying of TCP ACK packages should do the trick with regard to inbound traffic – although, certainly, not perfectly so.

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