ccna 200-301 exam guide

ccna 200-301 exam guide.Update Timer The time interval at which the routing protocol sends the next periodic routing update. The Distance Vector Routing Protocol sends a complete routing update at each update interval.Glossary 473Variance (Variance) IGRP and EIGRP calculate their own metric values, so different routes to the same subnet rarely have identical metric values. When multiple routes to the same subnet exist, the value of the variance goes to multiply the lowest metric value. If the product is greater than the metric values of the other routes, the route is considered to have the "same" metric value and is allowed toMultiple routes can be added to the routing table.Virtual Circuit (VC) A logical concept that represents the path a frame takes between two DTE devices. VCs offer many advantages when comparing Frame Relay to leased physical circuits.Virtual LAN (VLAN) A group of devices connected to one or more switches that can be configured to group into a single broadcast domain. VLANs allow the switch administrator to partition the devices connected to the switch into separate VLANs without physically separating the switches. The advantage of this design is that it separates both flowvolume without the need to purchase additional hardware.Virtual Private Network (VPN) A set of secure protocols implemented by devices at either end of an insecure network, such as the Internet, that allow devices to send data securely. VPNs provide confidentiality, device authentication,anti-retransmission and data integrity services.Virtual Router Redundancy Protocol (VRRP) This is a TCP/IP RFC protocol that allows two or more routers to share the default router within a subnet, and in an active/backup model, if the first router fails, the other active router will act as the default router and act as the default router by waiting to acquire the other router.