I'll add this to the document.
To be honest, I have never seen an implementation that
would do this after getting a udp DNS request, but
I so no harm in including the advice.
regards,
Ted
>
> The document doesn't seem to say anything about path MTU
> discovery (and potentially other ICMP error issues) for
> packets sent with an anycast source address.
>
> Since an ICMP "packet too big" will be sent back by a router to the anycast
> address it might not be delivered to the anycast member that actually
> sent the packet which might cause retransmissions with persistent
> packet loss.
>
> This fix is simply to point out that the responses from an anycast
> address must not use path MTU discovery i.e. must not have the DF bit set.
>
> I don't know of other ICMP errors that have similar issues.
>
