Stacking Dell PowerConnect 7000 Series Switches
Page 30
NSF Re-convergence Timing
As mentioned in the previous section, NSF protects against failures by check-pointing information to a
standby unit. In an NSF-protected stack, the worst-case scenario is when the master unit fails. The
following statistics show representative re-convergence times of an NSF-enabled standby switch as
measured from the detection of failure. With NSF enabled, data plane forwarding continues non-stop
on the non-failed switches while the standby unit converges the control plane protocols using the
check-pointed information. The re-convergence times given below include re-establishing
communication with the upper layer protocol peers, synchronization of shared information with the
peer, and re-establishment of any data plane forwarding paths around the failed master unit.
Medium Configuration
• 8 switches stacked
• 100 VLANs, all ports are members of all VLANs
• 4/4 static/dynamic lags with 8 members each
• 3 MSTP instance with VLANs
• 30 ACLs applied on 30 interfaces
• 10 Diffserv service interfaces with policies on 10 interfaces
• 6 VLAN routing interfaces
• 128 L2 Multicast group entries
• 512 ARP entries
• 128 Unicast routes
L2 loss duration (non-failed or rerouted stack member) 0 msec
L2 loss duration (failed/rerouted stack member)
L3 loss duration (failed/rerouted stack member) 12 msec
IPMC loss duration (failed/rerouted stack member)
L3 convergence time 25.410 sec
Total convergence time 25.420 sec
