HSRP (Hot Standby Router Protocol) is a cisco proprietary protocol. it is used for default gateway redundancy. It elects one router as active and one router as standby and puts all other routers in listen HSRP state. Active router is used as default gateway for hosts. It receives the ARP request from all the hosts… Read More »
VRRP (Virtual Router redundancy protocol) is an open standard default gateway redundancy protocol and it is is alternative for HSRP. It uses one router as master and all other routers are used as backup for master. A router with highest VRRP priority elects master and all other routers move in to VRRP backup state. If… Read More »
GLBP is a Cisco proprietary default gateway redundancy protocol. It provides the load balancing between virtual routers without using any trick. “Default gateway load balancing with HSRP and VRRP is a trick of multiple groups.” GLBP uses one router as an AVG and up to 4 routers as AVF. Every host sends the ARP request… Read More »
Cisco provides the feature of power redundancy on most of high end Cisco devices like 3650 , 6500 and 4500. These devices having the option of two PSU (Power supply unit) on single chassis. But both PSU should have input and output ratings. Power redundancy can be configure in two ways: Combined mode and Redundant… Read More »
PoE stands on power over Ethernet. It is used to provide the DC power over Ethernet cable through switch port. it can provide maximum 48 V DC over Ethernet cable that is applied from a power capable switch. A switch can offer the power to IP phones or to any powered device that can request… Read More »