Limit Duplicate ACK Rate

Onload User Guide (UG1586)

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1.2 English

The environment variable, EF_INVALID_ACK_RATELIMIT enables Onload support for the Linux tcp_invalid_ratelimit where the aim is to reduce the number of duplicate ACKs in response packets on an existing connection, but invalid for any of the following reasons:

  • out-of-window ACK number
  • out-of-window sequence number
  • ACK for PAWS check failure.

The rate limit, applied per-socket, is the minimal time gap between sending dupacks.

The default rate is that from /proc/sys/net/ipv4/tcp_invalid_ratelimit.