CCNP Switch Questions/Answers Implementing High Availability and Redundancy

Transcription

1 Which Catalyst 6500 switch component integrates on individual line modules as well as on the supervisor engine? A. CPU B. Flash C. ASIC D. NVRAM Answer: C Cisco Catalyst 6500 Series with Cisco IOS Software Modularity boosts operational efficiency and minimizes downtime through evolutionary software infrastructure advancements. By enabling modular Cisco IOS subsystems to run in independent processes: Minimizes unplanned downtime through selfhealing processes; Simplifies software changes through subsystem In-Service Software Upgrades (ISSU); Enables process-level, automated policy control by integrating Embedded Event Manager (EEM). The Catalyst 6500 Series delivers hardware-based forwarding through Application-Specific Integrated Circuits (ASICs) on a central Policy Feature Card (PFC) or Distributed Forwarding Cards (DFC). The control plane functions on the Catalyst 6500 Series run on dedicated CPUs on the Multilayer Switch Forwarding Card (MSFC) complex. The control plane manages control traffic such as routing protocol updates and management traffic; The data plane is responsible for the actual forwarding of packets using ASICs. Figure 1 Cisco Catalyst 6500 Series with Cisco IOS Software Modularity

2 Refer to the exhibit. What action does the command standby 1 track Serial 0/0/0 on router R1 perform? A. It links the default gateway virtual address to the IP address on interface Serial 0/0/0. B. It links the default gateway virtual address to the IP address on interface Serial 0/0/0. C. It tracks the state of the fa 0/0 interface on R1 and brings down the priority of standby group 1 if the interface goes down. D. It tracks the state of the Serial 0/0/0 interface on R1 and brings down the priority of standby group 1 if the interface goes down. Answer: D HSRP is Cisco-proprietary redundancy protocol, which enables routers that are part of HSRP group to act as single gateway for the hosts in present network. Routers in HSRP group send every 3 seconds Hello packets to inform other HSRP routers in HSRP group about their present state and presence in the network. HSRP router in HSRP group, which got highest priority, is active HSRP router. Virtual IP address is assigned to the HSRP group. If multiple routers in HSRP group got same priority, then router

3 with highest real IP address is elected as active HSRP router. HSRP router that got second highest priority in HSRP group is elected as standby HSRP router. All other routers in HSRP group remain in listen state. With command standby 1 track Serial 0/0/0 it is enabled tracking of state of interface Serial0/0/0, for R1 HSRP router, which is part of HSRP group 1. If interface Serial0/0/0is disabled, then priority of R1 HSRP router will be decreased for 10 (10 is default value that priority will be decreased if interface goes down)

4 Refer to the exhibit. What statement is true about the output of the show standby command? A. The current priority of this router is 120. B. The router is currently forwarding packets. C. The router is tracking two properly operating interfaces. D. This router is in the HSRP down state because its tracked interfaces are down. Answer: B From the show command above we can see that this router is active HSRP router in HSRP group 1. That is announced from line Active Router is local

5 Refer to the exhibit. Switch DSw1 is the Active Virtual Gateway (AVG) and DSw2 is an Active Virtual Forwarder (AVF). Based on this information, which two GLBP statements are true? (Choose two) A. GLBP is a Cisco proprietary protocol supported on all Cisco Catalyst and Cisco router platforms. B. None of the switches have had their priority configured. C. Switch DSw1 assigns the virtual IP addresses to switch DSw2. D. Switch Dw1 priority is 100 and switch DSw2 priority is 50. E. Two more multilayer switches could join this group. F. When host A sends an ARP message for the gateway IP address, switch DSw1 returns the physical address of switch DSw2. Answer: D, E GLBP is a Cisco-proprietary solution created to enable automatic selection and simultaneous use of multiple available gateways in addition to automatic failover between those gateways. Multiple routers

6 share the load of frames that, from a client perspective, are sent to a single default gateway address. With GLBP, resources can be fully utilized without the administrative burden of configuring multiple groups and managing multiple default gateway configurations, as is required with HSRP and VRRP. GLBP active virtual gateway (AVG) - Members of a GLBP group elect one gateway, to be the AVG for that group. Other group members provide backup for the AVG if the AVG becomes unavailable. The AVG assigns a virtual MAC address to each member of the GLBP group. GLBP active virtual forwarder (AVF) - Each gateway assumes responsibility for forwarding packets that are sent to the virtual MAC address assigned to that gateway by the AVG. These gateways are known as AVFs for their virtual MAC address. The following are the features of GLBP: Load sharing - You can configure GLBP in such a way that multiple routers can share traffic from LAN clients, thereby sharing the traffic load more equitably among available routers; Multiple virtual routers - GLBP supports up to 1024 virtual routers (GLBP groups) on each physical interface of a router and up to four virtual forwarders per group; Preemption - The redundancy scheme of GLBP enables you to preempt an AVG with a higher priority backup virtual gateway that has become available. Forwarder preemption works in a similar way, except that forwarder preemption uses weighting instead of priority and is enabled by default; Efficient resource utilization - GLBP makes it possible for any router in a group to serve as a backup, which eliminates the need for a dedicated backup router because all available routers can support network traffic

7 Refer to the exhibit. Based on the provided configuration, which routers are the master and the backup virtual routers for the hosts Host1, Host2, Host3 and Host4? A. Router R1 is the master for all hosts and router R2 is the backup for all hosts in the group. B. Router R1 is the master for Host1 and Host2. Router R2 is the master for Host3 and Host4. C. Router R1 is the master for Host3 and Host4. Router R2 is the backup for Host3 and Host4. D. Because of incorrect configuration of the default gateway on the hosts, none of the routers is the master for the VRRP group. Answer: B R1 and R2 are configured with different VRRP groups; VRRP group 1 for R1with Virtual IP address and VRRP group 2 for R2 with Virtual IP address R1 and R2 are not part of the same VRRP group. R1 is master VRRP router for VRRP group 1 and R2 is master VRRP router for VRRP group 2. Host1 and Host2 as default-gateway use Virtual IP address router R1. Host3 and Host4 as default-gateway use Virtual IP address of router R

8 How does Cisco IOS Server Load Balancing (SLB) enhance security of a real server? A. The IP address of the real server is not needed with IOS SLB, which relies only on MAC addresses. B. The IP address of the real server is translated with Network Address Translation (NAT). C. The IP address of the real server is advertised as part of a distinct network. D. The IP address of the real server is never announced to the external network. Answer: D Using Cisco IOS SLB for redundancy, scalability, and performance (load balancing) provides the following benefits: - High performance is achieved through the distribution of client requests across a cluster of servers. - Administration of server applications is easier. Clients know only about virtual servers; no administration is required for real server changes, making Cisco IOS SLB highly scalable. - Security of the real server is provided because its address is never announced to the external network. Users are familiar only with the virtual IP address. Additionally, filtering of unwanted traffic can be based on both IP address and IP port numbers. - Ease of maintenance with no downtime is achieved by allowing physical (real) servers to be transparently placed in or out of service while other servers handle client requests. - Switches detect servers, which are not responding and do not forward further requests, to those servers, until they begin to respond to polls from the switch. In summary, Cisco IOS SLB enables users to represent a group of network servers (a server farm in a data center) as a single server instance, balance the traffic to the servers, and limit traffic to individual servers. The single server instance that represents a server farm is referred to as a virtual server

9 How is server IP addressing handled by Cisco IOS Server Load Balancing (SLB) in dispatched mode? A. The default gateway address for the subnet is assigned to the virtual server. B. The real servers are configured with the virtual server address as loopback addresses or secondary IP addresses. C. The virtual server is assigned an IP address unknown to any of the real servers. D. The real servers are configured with IP addresses that differ by a power of 2. Answer: B More on: Link

10 What three steps will configure Cisco IOS Server Load Balancing (SLB) in a server farm that is in a data center with real servers? A. Globally enable IOS SLB. B. Define the server farm. C. Add a trunk link to the switch to connect the real servers. D. Associate the real server with the server farm. E. Define the virtual IP address. F. Enable the real server and define it to be used for the server farm. Answer: B, D, F The following steps describe how to configure Cisco IOS SLB in a server farm in a data center with real servers: Step 1. Define the server farm: Switch(config)# ip slb serverfarm serverfarm-name Step 2. Associate the real server with the server farm: Switch(config-slb-sfarm)# real ip-address-of-the-real-server Step 3. Enable the real server defined to be used for the Cisco IOS server farm: Switch(config-slb-real)# inservice

11 Refer to the exhibit. Based on the output, how many virtual servers are required? A. Zero B. One C. Two D. Three E. Four F. Five Answer: C Real servers with ip addresses , and are part of PUBLIC virtual server. Real servers with ip addresses and are part of RESTRICTED virtual server