Network & Email · page 19

Computes payload-to-wire overhead percentage per stack.

Explains speedtest results and common misreads like oversubscription.

Chooses CAKE keywords and bandwidth settings for a link profile.

References fq_codel targets, intervals, and quantum tuning.

Compares codel, fq_codel, CAKE, and FQ queue disciplines.

Plans RX and TX ring sizes per traffic class and pps load.

Explains coalescing tradeoffs between latency and CPU use.

Explains GRO, GSO, TSO, and LSO effects on captures and latency.

Computes MSS values from per-link MTU including tunnels.

Tables TCP window scale factors and maximum windows.

Explains Nagle and delayed ACK interaction and TCP_NODELAY use.

Plots slow start growth numbers across RTTs.

Converts between pps and bps at chosen frame sizes.

Assembles a v=spf1 record from include, ip4, and ip6 mechanism inputs.

Counts DNS-qualifying mechanisms in a pasted SPF record against the 10-lookup limit.

Decodes i, s, d, l, and o macros with worked expansion examples.

Explains plus, minus, tilde, and question mark qualifiers and fail handling.

Plans include flattening and its refresh cadence under the lookup limit.

Explains the redirect modifier semantics and evaluation ordering.

Builds a DKIM TXT record from selector, key type, and public key inputs.

Plans selector naming and rollover schedule for key rotation.

Compares 1024 and 2048 bit keys with provider support notes.

Generates a DMARC tag string with policy, reporting, and alignment tags.

Explains relaxed versus strict alignment for SPF and DKIM with examples.