Graceful Restart - Siemens S223 User Manual

User Manual
SURPASS hiD 6615 S223/S323 R1.5
i
10.1.2.5
A50010-Y3-C150-2-7619
To compare MED values on the exchange of path information between Confederation
Peers, use the following command.
Command
bgp bestpath med confed [ miss-
ing-as-worst ]
bgp bestpath med missing-as-
worst [ confed ]
To ignore MED values of paths on the exchange of information between confederation
peers, use the following command.
Command
no bgp bestpath med confed
[ missing-as-worst ]
no bgp bestpath med missing-
as-worst [ confed ]
If there are several equal paths, one of them has no MED value. Because this path is
considered as "zero" without MED value, it will be chosen the best path. But the path
would be the worst one if it has no MED value after missing-as-worst is set.
After missing-as-worst parameter is configured in the system, the path will be recog-
nized as the worst path without MED value.

Graceful Restart

Graceful restart allows a router undergoing a restart to inform its adjacent neighbors and
peers of its condition. The restarting router requests a grace period from the neighbor or
peer, which can then cooperate with the restarting router. With a graceful restart, the re-
starting router can still forward traffic during the restart period, and convergence in the
network is not disrupted. The restart is not visible to the rest of the network, and the re-
starting router is not removed from the network topology.
The main benefits of graceful restart are uninterrupted packet forwarding and temporary
suppression of all routing protocol updates. Graceful restart thus allows a router to ex-
change path information with the neighboring router.
To configure graceful restart specifically for BGP, use the following command.
Command
bgp graceful-restart
no bgp graceful-restart
Therefore, 2 options of the time can be used to speed up routing convergence by its peer
in case that BGP doesn't come back after a restart.
Mode
Configures the router to consider the MED in choosing
Router a path from among the paths on the exchange of in-
formation between confederation peers.
Mode
Ignores MEDs of paths on the exchange of their infor-
Router
mation between confederation peers.
Mode
Sets to use graceful restart in BGP protocol.
Router
Disables the restart time value setting.
UMN:CLI
Description
Description
Description
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