bgp: T9404: do not render "bgp default local-preference" when the value is 100

FRR does not print "bgp default local-preference 100" in show
running-config because 100 is its default, so frr-reload never finds the
line in the running config and sends it again on every reload. The
command handler calls bgp_clear_star_soft_in() whether or not the value
changed, so every reload ran "clear bgp * soft in" (once in pass 0 and
twice in pass 1), a full inbound re-evaluation of every peer.

Add the default (100) to the XML definition of parameters default
local-pref. Templates cannot query the XML definition while rendering,
so frrender takes the value from the config defaults of "parameters
default" (conf.get_config_defaults) and adds it to the BGP dict as the
key xml_default_local_pref, for the global instance and for every VRF
instance. bgpd.frr.j2 renders the line only when the configured value
differs from xml_default_local_pref, so the value 100 is not hardcoded
in the template. A real value change (100 to 200, or 200 to 100) is
still sent: frr-reload sees the difference between the rendered file and
the running config.

0 files changed, 0 insertions, 0 deletions