bgp: Allow router Stop without full destroy to fix Graceful Restart #39835
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GoBGP sends a Cease notification to all BGP peers as part of the server Stop() implementation, which terminates Graceful Restart progress on the peered routers. To make Graceful Restart work, allow stopping the router without destroying GoBGP server, at least until GoBGP provides a way to not send Cease notifications upon server Stop() to GR-enabled peers. The Router Stop() method now takes a StopRequest argument, which can be used to specify whether full destroy of the Router is needed or not. Full destroy is helpful for tests, but for now it should not be used for standard Cilium agent use-case to make GR work upon agent termination. Signed-off-by: Rastislav Szabo <rastislav.szabo@isovalent.com>
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/test |
harsimran-pabla
approved these changes
Jun 2, 2025
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Should the label be release-note/bug? |
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As of #38008,
BGPRouterManager.Stop()is called when BGP CP cell is being destroyed to properly clean up all servers when the agent is stopped. This change however affected Graceful Restart behavior and should be revisited:GoBGP sends a Cease notification to all BGP peers as part of the server
Stop()implementation (code ref), which makes Graceful Restart on the peered routers ineffective.From rfc4724, section 4 - Graceful Restart Mechanism for BGP:
To make Graceful Restart work, we allow stopping the router without destroying GoBGP server, at least until GoBGP provides a way to not send Cease notifications upon server
Stop()to GR-enabled peers.The Router's
Stop()method now takes aStopRequestargument, which can be used to specify whether full destroy of the Router is needed or not. Full destroy is helpful for tests, but for now it should not be used for standard Cilium agent use-case to make GR work upon agent termination.