Siemens S323 User Manual

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User Manual                                                                               UMN:CLI 
SURPASS hiD 6615 S223/S323 R1.5 
A50010-Y3-C150-2-7619                                                                         323 
To compare MED values on the exchange of path information between Confederation 
Peers, use the following command. 
Command Mode 
Description 
bgp bestpath med confed
 [miss-
ing-as-worst
bgp bestpath med missing-as-
worst 
[confed] 
Router 
Configures the router to consider the MED in choosing 
a path from among the paths on the exchange of in-
formation between confederation peers. 
 
To ignore MED values of paths on the exchange of information between confederation 
peers, use the following command.   
Command Mode 
Description 
no bgp bestpath med confed
 
[missing-as-worst
no bgp bestpath med missing-
as-worst 
[confed] 
Router 
Ignores MEDs of paths on the exchange of their infor-
mation between confederation peers. 
 
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. 
 
10.1.2.5 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 Mode 
Description 
bgp graceful-restart
 
Sets to use graceful restart in BGP protocol. 
no bgp graceful-restart 
Router 
Disables the restart time value setting. 
 
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. 
 
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