RFC 4890:Recommendations for Filtering ICMPv6 Mess...
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IP packet


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... ICMPv6 error messages or tunnel inappropriate encapsulated IP packets in ICMPv6 error messages. This problem can be alleviated by filtering ICMPv6 errors ...


... transparent to the IP layer although they will actually be inspecting the IP packets as they pass through (firewall/bridges). ...



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