ccna for dummies pdf

ccna for dummies pdf.Supports plaintext and MD5 authentication Supports plaintext and MD5 authenticationWorks on UDP (port number 1985) Works on IP (protocol number 112)Like HSRP, VRRP determines the role of each router in the backup group (Master router or Backup router) based on priority. The higher the priority, the more likely it is to be the Master router. o The virtual IP address in VRRP can be the same as the IP address on the router port. o The VRRP priority can range from 0.255 (a higher value indicates a higher priority) to a configurable 1.254, with priority 0 reserved for special purposes and 255 reserved for when the virtual IP address is the same as the real IP address. 255 is reserved for when the virtual IP address is the same as the real IP address. When the router's virtual IP address is the real IP address of the physical port, its priority is always 255.Chapter 15 EtherChannel and FHRP.255.Therefore. when the physical port IP address within the backup group is used as the virtual IP address. as long as it is working properly. the Master router.There are three VRRP timers: the advertisement interval timer, the time lag time timer, and the master failure interval timer.1 Advertisement interval: The Master router in the VRRP backup group sends VRRP advertisement messages at regular intervals to notify the routers in the backup group that they are working normally. You can set the VRRP timer to adjust the time interval for the Master router to send VRRP announcement messages, which is 1 second by default.2 Time lag time timer (SkewTime): The value is calculated as (256 - priority /256),unit seconds.3 MasterDowninterval timer: If the Backup router does not receive a VRRP announcement message after waiting for three announcement intervals, it considers itself the Master router and sends an outbound VRRP announcement packet to re-elect the Master router. The Backup router does not immediately seize the Master, but waits for a certain amount of time (time lag) before sending out a VRRP announcement message to replace the original Master router, so the timer value = 3x announcement interval + (256 - priority /256) seconds.15.3 Configuring EtherChannel and FHRP