In Figure 8-3, RTC and RTD can learn a 0/0 default or statically configure a 0/0 defaulttoward their respective providers. Under normal conditions, RTD automatically (or viacontrolled redistribution) injects the 0/0 into RIP. RTC detects the presence of a defaultoriginating from RTD, causing RTC to stop generating a default. All traffic is directed towardRTD. Figure 8-3. Injecting the 0/0 Default into RIP In case of a failure in the NY link, RTD stops generating the d..
Defaults Inside the AS: Primary/Backup BGP Policy
Consider the routing scenario shown in Figure 8-2. AS1 is connected to the Internet via twoconnections. RTC in SF is running Exterior Border Gateway Protocol (EBGP) with oneprovider, whereas RTD in NY is running EBGP with another provider. Inside the AS, RTCand RTD are running IBGP; however, they are not physically connected. As a result, trafficbetween RTC and RTD must flow through routers RTA and RTB. Figure 8-2. Following Defaults: Loop Situation Assume that RTC a..
The 802.6 DQDB standard never became popular as a means to interconnect LAN or digital telephony systems. Within the US, DQDB made a brief appearance as a commercial service in the form of the Switched Multimegabit Data Service (SMDS). However, in terms of tariff or capabilities, it never held any real advantage over Frame Relay, and had only marginal advantage over T1. Moreover, in many ways MANs are based upon the assumption that customers want to connect LANs at Layer 2. A..
The trick behind this load balancing lies in the GLBP group. One router is elected the active virtual gateway (AVG). This router has the highest priority value, or the highest IP address in the group, if there is no highest priority. The AVG answers all ARP requests for the virtual router address. Which MAC address it returns depends on which load-balancing algorithm it is configured to use. In any event, the virtual MAC address supported by one of the routers in the group is..
The phenomenal success of the Internet has made users' demand for more bandwidth ever increasing. Today's data networks support a variety of traffic with different characteristics and requirements for bandwidth. Among these are voice and video. Voice over IP and video on demand are now common applications on the Internet. Voice and video traffic are highly susceptible to latency and jitters. Applications that are more tolerant to time delay, such as FTP and e-mail, are still..
