> I remember a case in Vienna where an Olsr daemon was its own neighbor, > because (over a bridged connection) one of its 2.4 GHz neighbors > bridged everything to a 5 GHz interface the local node could hear.
That's not the issue here -- a Babel node is allowed to be its own neighbour, and this happens routinely on multi-radio nodes. The loop avoidance mechanism will ensure that such a looping link is never used for routing. (Interestingly, this was not planned -- it's yet another pleasant consequence of having a loop-avoidance mechanism built into the protocol core.) The issue here is different -- when babeld thinks that a link is wired, it disables link cost estimation in favour of 2-out-of-3 link sensing (see Appendix A of RFC 6126). 2-out-of-3 is extremely unstable in the presence of persistent packet loss, since it drops a link as soon as two packets in a row are lost. This spurious instability leads to increased control traffic, which in turn leads to increased CPU usage. -- Juliusz _______________________________________________ Babel-users mailing list [email protected] http://lists.alioth.debian.org/cgi-bin/mailman/listinfo/babel-users
