From 1c7ce32e6fce1d6ed750d58168ecfb60cb30dd1b Mon Sep 17 00:00:00 2001 From: lemoer Date: Sat, 6 Jan 2018 00:18:39 +0100 Subject: [PATCH] gluon-radv-filterd: improve documentation of selected router --- docs/package/gluon-radv-filterd.rst | 27 +++++++++++++++++---------- 1 file changed, 17 insertions(+), 10 deletions(-) diff --git a/docs/package/gluon-radv-filterd.rst b/docs/package/gluon-radv-filterd.rst index e4f72b52..14566f32 100644 --- a/docs/package/gluon-radv-filterd.rst +++ b/docs/package/gluon-radv-filterd.rst @@ -7,22 +7,29 @@ default router with the best metric according to B.A.T.M.A.N. advanced. Note that advertisements originating from the node itself (for example via gluon-radvd) are not affected and considered at all. -"Best" router +Selected router ------------- -The best router is determined by the TQ that is reported for its originator by -B.A.T.M.A.N. advanced. If, for some reason, another gateway with a better TQ -appears or an existing gateway increases its TQ above that of the chosen -gateway, the chosen gateway will remain selected until the better gateway has a -TQ value at least X higher than the selected gateway. This is called -hysteresis, and X can be specified on the commandline/via UCI/the site.conf and -defaults to 20 (just as for the IPv4 gateway selection feature built into -B.A.T.M.A.N. advanced). +The router selection mechanism is independent from the batman-adv gateway mode. +In contrast, the device originating the router advertisment could be any router +or client connected to the mesh, as radv-filterd captures all router +advertisements originating from it. All nodes announcing router advertisement +**with** a default lifetime greater than 0 are being considered as candidates. + +In case a router is not a batman-adv originator itself, its TQ is defined by +the originator it is connected to. This lookup uses the batman-adv global +translation table. + +Initially the router is the selected by choosing the candidate with the +strongest TQ. When another candidate can provide a better TQ metric it is not +picked up as the selected router until it will outperform the currently +selected router by X metric units. The hysteresis threshold is configurable +and prevents excessive flapping of the gateway. "Local" routers --------------- -The package has functionality to assign "local" routers, i.e. those connected +The package has functionality to select "local" routers, i.e. those connected via cable or WLAN instead of via the mesh (technically: appearing in the ``transtable_local``), a fake TQ of 512 so that they are always preferred. However, if used together with the :doc:`package/gluon-ebtables-filter-ra-dhcp`