[Babel-users] Bucket full, dropping packet

[Juliusz Chroboczek]

> Warning: bucket full, dropping packet to digger1438.
> Warning: bucket full, dropping unicast packet to
> fe80::2ff:c3ff:fec1:a81c if digger1438.
> Warning: bucket full, dropping packet to digger1438.

This means that the last-resort token bucket triggered, and caused some
packets to be dropped.  Either you've triggered a bug that causes babeld
to spam, or your network is so large that the token bucket needs tuning.

How large is your network?  How many routes through how many neighbours?

The token bucket is at message.c line 801, and the default parameters are

  #define BUCKET_TOKENS_MAX 200
  #define BUCKET_TOKENS_PER_SEC 40

That means 40 packets per second, including unicast packets.  That's not
a lot, but Babel is not a noisy protocol.  I'll multiply both values by 10
for the next version, and make them runtime-configurable.

> Any hints on what may be the problem? These might or might not be
> related to some route instability even when there is no packet loss on
> the underlying L2 links.

Yes, the receiver doesn't know the cause of packet loss -- it treats
link-layer packet loss the same as loss due to congestion.

-- Juliusz