If we don't have the ICMP hint available, such as on Android, we can use
the signal of rx traffic to bias toward a particular endpoint.
We don't want to stick to a particular endpoint for a very long time
without any signals, so the sticky time is reduced to 1 second, which is
large enough to avoid excessive packet reordering in the common case,
but should be small enough that either rx provides a strong signal, or
we rotate in a user-interactive schedule to another endpoint, improving
the feel of failover to other endpoints.
Updates #8999
Co-authored-by: Charlotte Brandhorst-Satzkorn <charlotte@tailscale.com>
Signed-off-by: James Tucker <james@tailscale.com>
Signed-off-by: Charlotte Brandhorst-Satzkorn <charlotte@tailscale.com>
Now a nodeAttr: ForceBackgroundSTUN, DERPRoute, TrimWGConfig,
DisableSubnetsIfPAC, DisableUPnP.
Kept support for, but also now a NodeAttr: RandomizeClientPort.
Removed: SetForceBackgroundSTUN, SetRandomizeClientPort (both never
used, sadly... never got around to them. But nodeAttrs are better
anyway), EnableSilentDisco (will be a nodeAttr later when that effort
resumes).
Updates #8923
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>