Dell Z9100 EMC Networking with Isilon Front-End Deployment and Best Practices - Page 22

BGP hello and hold down timers are set to three and nine seconds

Page 22 highlights

Z9100-ON Spine 1 route-map spine-leaf permit 10 match ip address prefix-list spine-leaf Z9100-ON Spine 2 route-map spine-leaf permit 10 match ip address prefix-list spine-leaf ip prefix-list spine-leaf seq 10 permit 10.0.1.0/24 ge ip prefix-list spine-leaf seq 10 permit 10.0.1.0/24 ge 32 32 Use these commands to configure BGP. First, enable eBGP with the router bgp ASN command. The ASN is from Figure 14. The bgp bestpath as-path multipath-relax command enables ECMP. The maximum-paths ebgp 2 command specifies the maximum number of parallel paths to a destination to add to the routing table. In this topology, there are two equal cost best paths from a spine to a host, one to each leaf that the host is connected. BGP neighbors are configured, and Neighbor fall-over is enabled. Graceful restart enables the data plane to continue forwarding traffic for a time if the BGP process fails or quits. BGP hello and hold down timers are set to three and nine seconds, respectively. Neighbor fall-over will trigger route withdrawal when IP connectivity between BGP peers is lost. The more aggressive timers (default is 60 seconds hello and 180 seconds hold down) are for backup. The advertisement interval is set to one second. This is to prevent BGP speakers from advertising updates immediately upon receipt. Instead, they will advertise them in batched intervals of one second. This delay is to prevent overhead. Finally, exit configuration mode and save the configuration. 22 Dell EMC Networking with Isilon Front-End Deployment and Best Practices Guide | version 1.0

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22
Dell EMC Networking with Isilon Front-End Deployment and Best Practices Guide | version 1.0
Z9100-ON Spine 1
Z9100-ON Spine 2
route-map spine-leaf permit 10
match ip address prefix-list spine-leaf
ip prefix-list spine-leaf seq 10 permit 10.0.1.0/24 ge
32
route-map spine-leaf permit 10
match ip address prefix-list spine-leaf
ip prefix-list spine-leaf seq 10 permit 10.0.1.0/24 ge
32
Use these commands to configure BGP.
First, enable eBGP with the
router bgp ASN
command. The ASN is from Figure 14.
The
bgp bestpath as-path multipath-relax
command enables ECMP. The
maximum-paths ebgp
2
command specifies the maximum number of parallel paths to a destination to add to the routing table. In
this topology, there are two equal cost best paths from a spine to a host, one to each leaf that the host is
connected.
BGP neighbors are configured, and Neighbor fall-over is enabled. Graceful restart enables the data plane to
continue forwarding traffic for a time if the BGP process fails or quits.
BGP hello and hold down timers are set to three and nine seconds, respectively. Neighbor fall-over will trigger
route withdrawal when IP connectivity between BGP peers is lost. The more aggressive timers (default is 60
seconds hello and 180 seconds hold down) are for backup. The advertisement interval is set to one second.
This is to prevent BGP speakers from advertising updates immediately upon receipt. Instead, they will
advertise them in batched intervals of one second. This delay is to prevent overhead.
Finally, exit configuration mode and save the configuration.