Dell C1048P Port Extender Networking Configuration Guide for the C9000 Series - Page 419

Dynamic Re-calculation of Link Bankwidth The Link cost associated with a port channel interface (LAG) changes whenever a member is added or deleted. Continuous link flapping results in the re-calculation of the link costs. This behaviour also causes unnecessary processing overhead on the device as it advertises these changed link costs to its peers and updates its RTM when ever there is a change in the member status. To avoid the re-calculation of Link costs for continuous link flaps, the updated link cost is re-calculated using a timer. This timer is activated every five minutes to check if there is any change in the link cost associated with the EBGP neighbors (directly connected). Weighted ECMP for Static Routes Dell Networking OS also supports Weighted ECMP for static routes. You can configure weights corresponding to the paths for a static destination. If all configured paths have weights, traffic distribution is performed using the Weighted ECMP method with the RTM these passing weights to the FIB. If all configured paths do not have weights, regular ECMP is used to determine traffic paths. Also, paths that are configured with a weight value of 0 are explicitly excluded from Weighted ECMP calculations. The RTM does not inform the FIB about these paths (next-hops). NOTE: Dell Networking OS also supports a global configuration parameter to enable or disable Weighted ECMP for static routes on the system. The following example shows weighted ECMP configuration for Static Routes: Dell(conf)#ip route 1.1.1.0/24 4.4.4.2 weight 100 Dell(conf)#ip route 1.1.1.0/24 6.6.6.2 weight 200 Dell#show running-config | grep route ip route 1.1.1.0/24 4.4.4.2 weight 100 ip route 1.1.1.0/24 6.6.6.2 weight 200 Dell(conf)#ip route vrf test 1.1.1.0/24 4.4.4.2 weight 100 Dell(conf)#ip route vrf test 1.1.1.0/24 6.6.6.2 weight 200 Dell(conf)# Dell(conf)# Dell#show running-config | grep route ip route vrf test 1.1.1.0/24 4.4.4.2 weight 100 ip route vrf test 1.1.1.0/24 6.6.6.2 weight 200 Equal Cost Multi-Path (ECMP) 419