| The Foundation Summary is a collection of information that provides a convenient review of many key concepts in this chapter. If you are already comfortable with the topics in this chapter, this summary can help you recall a few details. If you just read this chapter, this review should help solidify some key facts. If you are doing your final preparation before the exam, this information is a convenient way to review the day before the exam. Table 14-7. Comparison of Router Redundancy Protocols| | HSRP | VRRP | GLBP |
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Standardized | No; Cisco-proprietary, RFC 2281 | Yes; RFC 2338 | No; Cisco-proprietary | Router roles | Active router, standby router | Master router, backup router | AVG, AVF | Load balancing | Only through multiple HSRP groups, different client gateways | Only through multiple VRRP groups, different client gateways | Inherent with one GLBP group; all clients use same gateway; several methods available | Interface tracking | Yes | No | Yes | Virtual router MAC address | 0000.0c07.acxx | 0000.5e00.01xx | Assigned by AVG |
Table 14-8. HSRP Configuration CommandsTask | Command Syntax |
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Set the HSRP priority | standby group priority priority | Set the HSRP timers | standby group timers hello holdtime | Allow router pre-emption | standby group preempt [delay seconds] | Use group authentication | standby group authentication string | Adjust priority by tracking an interface | standby group track type mod/num decrementvalue | Assign the virtual router address | standby group ip ip-address [secondary] |
Table 14-9. VRRP Configuration CommandsTask | Command Syntax |
|---|
Assign a VRRP router priority (default 100) | vrrp group priority level | Alter the advertisement timer (default 1 second) | vrrp group timers advertise [msec] interval | Learn the advertisement interval from the master router | vrrp group timers learn | Disable pre-empting (default is to pre-empt) | no vrrp group preempt | Change the pre-empt delay (default 0 seconds) | vrrp group preempt [delay seconds] | Use authentication for advertisements | vrrp group authentication string | Assign a virtual IP address | vrrp group ip ip-address [secondary] |
Table 14-10. GLBP Configuration CommandsTask | Command Syntax |
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Assign a GLBP priority | glbp group priority level | Allow GLBP pre-emption | glbp group preempt [delay minimum seconds] | Define an object to be tracked | track object-number interface type mod/num {line-protocol | ip routing} | Define the weighting thresholds | glbp group weighting maximum [lower lower] [upper upper] | Track an object | glbp group weighting track object-number [decrement value] | Choose the load-balancing method | glbp group load-balancing [round-robin | weighted | host-dependent] | Assign a virtual router address | glbp group ip [ip-address [secondary]] |
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