ERSPAN supports source ports, source VLANs, and destinations on different switches, which provides remote monitoring of multiple switches across your network (see Figure 41-3). ERSPAN uses a GRE tunnel to carry traffic between switches. ERSPAN consists of an ERSPAN source session, routable ERSPAN GRE-encapsulated traffic, and an ERSPAN destination session. You separately configure ERSPAN source sessions and destination sessions on different switches. To configure an ERSPAN so..
The link-state update packet, OSPF packet type 4, is sent in response to the link-state request packet and implements the flooding of LSAs. The link-state update packet carries a collection of LSAs one hop from its origin. Several LSAs can be included in a single update. Each LSA must be acknowledged. In response to the link-state update, a link-state acknowledgment packet is sent to multicast addresses on the networks that support multicast. If retransmission o..
QoS is disabled by default; however, the radio interface always honors tagged 802.1P packets even when you haven't configured a QoS policy. QoS can be configured through either the Cisco IOS (MQC) CLI or the web-interface configuration utility provided by the AP software. The Cisco IOS MQC CLI provides a very familiar syntax for QoS configuration on Cisco APs. In Example 11-2, DSCP EF is mapped to IEEE 802.1D CoS 6 (the IEEE definition for voice CoS) and is applied to the IE..
Protecting Management Plane Access
Other than the previously mentioned requirement for physical security, network security can be used to limit access to a device’s management plane over a network connection. For example, ACLs can be created to permit only specific protocols (such as SSH as opposed to Telnet and HTTPS as opposed to HTTP) coming from specific sources (for example, the IP addresses of administrators) to access a device’s management plane. Once a connection is made with the device to be manag..
Congestion Indication Support in FRF.8.1
For FRF.8.1, Cisco supports the bidirectional mapping of FECN and EFCI bits outlined in Table 8-5. Table 8-5. Table 8-5. EFCI and FECN Mapping for FRF.8.1 Frame Relay to ATM Direction Default The EFCI field in the ATM cell header is set to 1 if the FECN field in the Frame Relay headers is set. User configurable The EFCI field in the ATM cell header is set to a constant 0. ATM ..
