SmartSwitch Router User Reference Manual 339Chapter 25: WAN Configuration GuideSource Filtering and ACLsSource filtering and ACLs can be applied to a WAN interface; however, they affect theentire module, not an individual port.For example, if you want to apply a source MAC address filter to a WAN serial cardlocated in slot 5, port 2, your configuration command line would look like the following:Port se.5 is specified instead of se.5.2 because source filters affect the entire WAN module.Hence, in this example, source-mac 000102:030405 would be filtered from ports se.5.1,se.5.2, se.5.3, and se.5.4 (assuming that you are using a four-port serial card).ACLs work in a similar fashion. For example, if you define an ACL to deny all http trafficon one of the WAN interfaces, it will apply to the other WAN interfaces on that module aswell. In practice, by making your ACLs more specific, for example by specifying sourceand destination IP addresses with appropriate subnet masks, you can achieve yourintended level of control.Weighted-Fair QueueingThrough the use of Weighted-Fair Queueing QoS policies, WAN packets with the highestpriority can be allotted a sizable percentage of the available bandwidth and “whiskedthrough” WAN interface(s). Meanwhile, the remaining bandwidth is distributed for“lower-priority” WAN packets according to the user’s percentage-of-bandwidthspecifications. Please refer to Chapter 35: “qos Commands” in the SmartSwitch RouterCommand Line Interface Reference Manual for more detailed configuration information.Note: Weighted-Fair Queueing applies only to best-effort traffic on the WAN card. Ifyou apply any of the WAN specific traffic shaping commands, then weighted fairqueuing will no longer be applicable.Congestion ManagementOne of the most important features of configuring the SSR to ensure Quality of Service isthe obvious advantage gained when you are able to avoid network congestion. Thefollowing topics touch on a few of the most prominent aspects of congestion avoidancewhen configuring the SSR.Random Early Discard (RED)RED allows network operators to manage traffic during periods of congestion based onpolicies. Random Early Discard (RED) works with TCP to provide fair reductions in trafficproportional to the bandwidth being used. Weighted Random Early Discard (WRED)ssr(config)# filters add address-filter name wan1 source-mac000102:030405 vlan 2 in-port-list se.5
