The recent update patch by Silamel has brought to my attention the origin_tries limitation in forward.cc preventing more than 2 reforward/retry when there is no cache_peer.

It seems to have been set to prevent large amount of looping when DIRECT attempts fail under the old model of constant DNS lookups and retries. However it is hard-coded and has no configuration knob visible. Under the new model of all destinations being enumerated once and tried sequentially this protection would seem to be no longer necessary and somewhat harmful as it will be preventing retries reaching destinations with more than 2 unreachable IPs (think 3 IPv6 and an IPv4 on IPv4-only network).

I think we need to drop the origin_tries counter entirely and rely on the n_tries limiter instead.

Opinions? alternative knowledge anyone?

Amos

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