gluon/docs/package/gluon-ebtables-limit-arp.rst
T-X bce76bcaf0 docs: Add documentation for gluon-mesh-batman-adv (#1810)
This adds documentation for the gluon-mesh-batman-adv package and
elaborates on its build and configuration options, as well as
the implemented multicast architecture.

Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
2019-09-10 23:55:06 +02:00

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gluon-ebtables-limit-arp
========================
The *gluon-ebtables-limit-arp* package adds filters to limit the
amount of ARP requests client devices are allowed to send into the
mesh.
The limits per client device, identified by its MAC address, are
6 packets per minute and 1 per second per node in total.
A burst of up to 50 ARP requests is allowed until the rate-limiting
takes effect (see ``--limit-burst`` in ``ebtables(8)``).
Furthermore, ARP requests for a target IP already present in the
batman-adv DAT cache are excluded from rate-limiting, in regard
to both counting and filtering, as batman-adv will be able
to respond locally without a burden for the mesh. Therefore, this
limiter should not affect popular target IP addresses, like those
of gateways or nameservers.
However it mitigates the impact on the mesh when a larger range of
its IPv4 subnet is being scanned, which would otherwise result in
a significant amount of ARP chatter, even for unused IP addresses.
This package is selected by default if the installed routing
package is gluon-mesh-batman-adv-14 or gluon-mesh-batman-adv-15.
It can be unselected via::
GLUON_SITE_PACKAGES := \
-gluon-ebtables-limit-arp