Introduction to First Hop Redundancy
           Proxy ARP
           Static Default Gateway
           HSRP
           VRRP
           GLBP
        Chapter 5
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          Proxy ARP
           Legacy solution.
           Enabled by default.
           Used before default 
                gateways were supported 
                on IP clients.
           End station acts as if 
                destination were on same 
                network segment.
           Relatively slow due to 
                reliance on aging out of 
                ARP cache.
        Chapter 5
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          Static Default Gateway
           Not dynamic.
           Does not provide 
                secondary path.
        Chapter 5
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          Hot Standby Router Protocol (HSRP)
           Cisco-proprietary gateway 
                redundancy protocol.
           Participating routers talk to 
                each other and agree on a 
                virtual router with a virtual 
                IP address which end 
                systems use as a default 
                gateway.
        Chapter 5
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          HSRP Failover
           When active router or links 
                between routers fail, the 
                standby router stops 
                seeing hello messages 
                from active router. Standby 
                router then assumes role 
                of forwarding router. 
           Because new forwarding 
                router assumes both IP 
                and MAC address of 
                virtual router, end stations 
                see no disruption in 
                service.
        Chapter 5
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