bgpd: bgpd-restart-bit-fix.patch

bgpd: bgpd-restart-bit-fix.patch

ISSUE:

Quagga BGP doesn't send or use the restart-bit via the Graceful-Restart(GR)
capability. GR capability implementation isn't complete as per the RFC.

PATCH:

Patch uses BGP instance creation as the beginning of the startup period,
and 'restart_time' is taken as the startup period. As a result, BGP will
set the restart bit in the GR capability of the OPEN messages during the
startup period.

As an indication of quagga implementation's capability of sending End-Of-RIB,
helping a restarting neighbor, quagga BGP will now send global GR capability
irrespective of the graceful-restart config in BGP and the address-family
specific GR capability will be sent only if the GR config is present.
Forwarding bit is not set assuming its not preserved.

Signed-off-by: Vipin Kumar <vipin@cumulusnetworks.com>
Reviewed-by: Pradosh Mohapatra <pmohapat@cumulusnetworks.com>