n To provide Network Acceleration, Silver Peaks require symmetric TCP flows. A network is asymmetric when a client request and its server response don’t use the same path through the network.
n Flow redirection removes asymmetry locally by merging the traffic of an asymmetric flow into a single appliance. When peer appliances are configured as a cluster, they keep track of which appliance first saw a flow and consequently “owns” that flow. If a return flow arrives at a peer that doesn’t own it, the flow is forwarded to the rightful owner via the mgmt1 interfaces.Note IMPORTANT — When configuring for flow redirection, the mgmt1 interfaces need to be in a separate subnet from the mgmt0 interfaces.
n An appliance that handles both directions of traffic for a flow can then optimize the flow properly. Specifically, this sets the stage for TCP acceleration and CIFS acceleration.
At Site A, the router uses PBR (Policy-Based Routing) to direct outbound traffic — arriving at its interface — to the VRRP Master, A1. Appliances A1 and A2 are advertising their subnet’s reachability to Appliance B. Because A1 and A2 are in the same subnet, they’re equally likely to receive the return flow.
•
• However, having been configured into a flow redirection cluster, the peers know that A1 owns the flow and forward it there. Since both directions traversed A1, the flow is symmetric and able to be TCP optimized.
1
2
a Change the default address to 10.10.10.1/30.
b
c Click Apply.
3
a Select Enable.
b
c
d Click Apply.
1
2
a Change the default address to 10.10.10.2/30.
b
c Click Apply.
3
a Select Enable.
b
c
d Click Apply.
4 To verify that flow redirection is working, look to see that the State changes to OK, indicating that the interfaces and flow redirection are configured properly on both sides.
Please send comments or suggestions regarding user documentation to techpubs@silver-peak.com. |