Although RFC 4271 does not forbid empty path segments, they are useless
and some implementations consider them invalid. It is clarified in RFC 7606,
specifying that AS_PATH with empty segment is considered malformed.
When 'import keep rejected' protocol option is activated, routes
rejected by the import filter are kept in the routing table, but they
are hidden and not propagated to other protocols. It is possible to
examine them using 'show route rejected'.
Allows to send and receive multiple routes for one network by one BGP
session. Also contains necessary core changes to support this (routing
tables accepting several routes for one network from one protocol).
It needs some more cleanup before merging to the master branch.
Hostcache is a structure for monitoring changes in a routing table that
is used for routes with dynamic/recursive next hops. This is needed for
proper iBGP next hop handling.
It seems that by adding one pipe-specific exception to route
announcement code and by adding one argument to rt_notify() callback i
could completely eliminate the need for the phantom protocol instance
and therefore make the code more straightforward. It will also fix some
minor bugs (like ignoring debug flag changes from the command line).
Process well-known communities before the export filter (old behavior is
to process these attributes after, which does not allow to send route
with such community) and just for routes received from other BGP
protocols. Also fixes a bug in next_hop check.
Although standard says that if we receive AS_PATH_CONFED_*
(and we are not a part of a confederation) segment, we should
drop session, nobody does that and it is unwise to do that.
Now we drop session just in case that peer ASN is in
AS_PATH_CONFED_* segment (to detect peer that considers BIRD
as a part of its confederation).
AS4 optional attribute errors were handled by session
drop (according to BGP RFC). This patch implements
error handling according to new BGP AS4 draft (*)
- ignoring invalid AS4 optional attributes.
(*) http://www.ietf.org/internet-drafts/draft-chen-rfc4893bis-02.txt
This patch extends the length for attributes from 1024 to 2048
(because both AS_PATH and AS4_PATH attributes take 2+4 B per AS).
If there is not enough space for attributes, Bird skips that
route group. Old behavior (skipping remaining attributes)
leads to skipping required attributes and session drop.
