A local SPAN session is an association of source ports and source VLANs with one or more destinations. You configure a local SPAN session on a single switch. Local SPAN does not have separate source and destination sessions. Local SPAN sessions do not copy locally sourced RSPAN VLAN traffic from source trunk ports that carry RSPAN VLANs. Local SPAN sessions do not copy locally sourced RSPAN GRE-encapsulated traffic from source ports. Each local SPAN session can have either po..
Designated Router Optimization on LANs
Figure 10-2 depicts the DR flooding optimization that occurs with sending DD packets over a LAN. Figure 10-2 DR Optimization on a LAN Routers that are not the DR (including the BDR) send DDs to the DR by sending them to multicast address 224.0.0.6, the All OSPF DR Routers multicast address. The DR then acknowledges the DDs with a unicast DD (Step 2 in Figure 10-2). The DR then floods a new DD packet to all OSPF routers (multicast address 224.0.0.5). Figure 10-2 shows..
Message switching is a technology that overlays packet- or circuit-switched networks. The routing paradigm is one of "store-and-forward." For example, suppose that, as shown in Figure 3-3, host X (Source) wants to send a message to host Y (Destination). Assume that host X cannot send the message directly to host Y because of network congestion, security limitations such as a firewall, or an outage. Instead, host X will pass the message to another node, C, that is closer to&nb..
Most of the features mentioned in the previous section are Cisco IOS features and pertain to employing CAC when Cisco IOS voice gateway routers connect traditional telephony equipment into an IP network. Much of the voice traffic in VoIP networks, however, originates from IP phones, not from gateways, and none of these features (other than potentially RSVP) applies to traffic from these devices. Therefore, Cisco CallManager has additional CAC features to cover the management..
Removing Passwords from a Router Configuration File
The following Perl script removes sensitive information like passwords and SNMP community strings from configuration files. The script takes the name of the file containing the router's configuration as its only command-line argument. Here's some sample output: Freebsd% strip.pl Router1-confg version 12.2service password-encryption!hostname Router1!aaa new-modelaaa authentication login default localenable secret <removed>enable password <removed>!username ij..
