Administrator Guide
ip address 3.3.3.1/24
no shut
router bgp 1
maximum-paths ebgp 2
bgp dmzlink-bw
neighbor 1.1.1.1 remote-as 1
neighbor 1.1.1.1 no shutdown
neighbor 3.3.3.2 remote-as 2
neighbor 3.3.3.2 dmzlink-bw
neighbor 3.3.3.2 no shutdown
R4#
interface tengigbitethernet 1/1
ip address 4.4.4.2/24
no shut
router bgp 2
maximum-paths ebgp 2
bgp dmzlink-bw
neighbor 4.4.4.1 remote-as 1
neighbor 4.4.4.1 dmzlink-bw
neighbor 4.4.4.1 no shutdown
R5#
interface tengigbitethernet 1/1
Ip address 5.5.5.2/24
no shut
interface fortGigE 1/48
ip address 3.3.3.2/24
no shut
router bgp 2
maximum-paths ebgp 2
bgp dmzlink-bw
neighbor 5.5.5.1 remote-as 1
neighbor 5.5.5.1 dmzlink-bw
neighbor 5.5.5.1 no shutdown
neighbor 3.3.3.1 remote-as 1
neighbor 3.3.3.1 dmzlink-bw
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.
350 Equal Cost Multi-Path (ECMP)