Technical data

Brocade ServerIron ADX Advanced Server Load Balancing Guide 137

53-1003441-01

Chapter

Pass-Through Flow Management

Pass-through flow management overview

Stateful devices, such as firewalls and Deep Packet Inspection (DPI) devices, require visibility into

both forward and reverse traffic flows to process them appropriately. These devices fail to function

if the network handles traffic asymmetrically.

Using the pass-through flow management feature, the ServerIron ADX supports stateful handling of

network flows while ensuring that it sends the reverse traffic to the same device that previously

forwarded it.

Pass-through flow management is a standalone feature and is applicable for TCP and UDP traffic

flows only. You can only combine it with the following ServerIron ADX features:

• Access control list (ACL)

• Layer 3 routing

• Any global session management-related commands that affect the session in general and are

not specific to a specific feature; for example, the server tcp-age minutes and server udp-age

minutes commands

Configuring pass-through flow management

By default, pass-through flow management is disabled on the ServerIron ADX. You can enable it by

configuring it under a physical or virtual interface.

• Under a physical interface, enter the following commands:

ServerIronADX(config)# interface ethernet 1/5

ServerIronADX(config-if-e10000-1/5)# flow-mgmt stick-to-sender

• Under a virtual interface, enter the following commands:

ServerIronADX(config)# interface ve v1

ServerIronADX(config-vif-1)# flow-mgmt stick-to-sender

Syntax: [no] flow-mgmt stick-to-sender

Pass-through flow management only applies to traffic that arrives on the interface under which it is

enabled. The flow-mgmt stick-to-sender command only affects the traffic initiated from the

configured interface. For example, you configure the command on interface e1, but you do not

configure it on interface e2. If the client initiates a connection, and the traffic arrives on e1 and

leaves through e2, the ServerIron ADX tracks the traffic in both directions; the forward traffic flows

from e1 to e2 and the reverse traffic flows from e2 to e1. However, if the client initiates a

connection, and the traffic arrives on e2 and leaves through e1, the ServerIron ADX does not track

the traffic in both directions; the forward traffic flows from e2 to e1 and the reverse traffic flows

from e1 to e2.