HSRP ensures router Redundancy

HSRP ensures router redundancy. What will happen if a router fails and enterprises cannot access the Internet? This is why redundancy needs to be provided in the network. Next we will teach you how to use the Hot Standby Router Protocol to ensure redundancy. What will happen if enterprises cannot access the Internet due to a router failure? Is it acceptable for enterprises? You may be able to escape the penalty for the moment, but you need to make a better plan, not just simple desktop call support. This is why redundancy needs to be provided in the network. Consider adding a backup path <script language = javascript src = "/cms/js/newsad. js"> </script> to the current vro. All enterprises need is hardware, and cisco Software will do other things. Let's examine how to use the hot backup router protocol (hsrp) to configure it.
What is hsrp? Www.2cto.com hsrp is cisco's proprietary protocol for redundancy. It provides almost 100% of router availability and redundancy. Therefore, if a router fails, the backup router takes over the routing function of the primary router. However, cisco also supports other available Industry protocols. One industry standard is vro redundancy protocol (vrrp ). Another alternative to hsrp is the gateway Load Balancing protocol (glbp), which is another private solution of cisco. Before we discuss how to configure hsrp, let's take a look at the networks used in this example. To help you better understand how hsrp works, here is a basic network chart: in our sample network, we configure the default gateway of the pc as IP address 10.1.1.3. However, this IP address does not point to a real device; instead, it acts as the virtual IP address of the primary router.
How does hsrp work? When using hsrp, The vro can be active or standby. If the master Router does not send a hello packet to the slave router for a period of time, the slave router assumes that the master router is disabled and takes over. Then, the Standby Router assumes that it is responsible for the virtual IP address and starts to respond to the virtual Ethernet mac address pointed to by the virtual IP address. The master and slave routers exchange hsrp hello packets, so they know where the other router is. These hello packets use multicast 224.0.0.2 and udp port 1985. The most basic form of hsrp is available from ios 10.0, but it has been released in ios 11 and 12 versions. What determines the active router? First, you can configure a priority number to determine it, and then it is determined by the highest IP address. The default priority value is 100. A higher priority value indicates the preferred router. Of course, when establishing vro redundancy, it is not limited to only two vrouters. In fact, you can create a router group that works together and have multiple "slave" routers.
How to configure hsrp? You can use the standby command to complete almost all hsrp configurations in the router interface configuration mode. Let's consider the steps used to configure the network displayed in the chart. For vro1:1. Configure the IP address www.2cto.com on the Ethernet interface. 2. Configure the backup IP address. 3. Configure the standby IP address. (If vro1 1 is available, it will always be the primary router .) For vro2 2: 1. Configure the IP address on the Ethernet interface 2. Configure the backup IP address 3. Configure the backup priority less than 100 (in this example, It is 99 .) Now, we will consider the configuration of the sample network. Router 1 (show running-config output) interface ethernet0/0 ip address 10.1.1.1 255.255.255.0 www.2cto.com standby ip 10.1.1.3 standby preempt router1 # show standby ethernet0/0-group 0 state is active 2 state changes, last state change 00:00:29 virtual ip address is 10.1.1.3 active virtual mac address is too c07.ac00 local virtual mac address is too c07.ac00 (default) hello time 3 sec, hold tim E 10 sec next hello sent in 0.692 secs preemption enabled active router is local standby router is 10.1.1.2, priority 99 (expires in 8.097 sec) www.2cto.com priority 100 (default 100) ip redundancy name is "hsrp-et0/0-0" (default) router1 # router 2 (show running-config output) interface ethernet0/0 ip address 10.1.1.2 255.255.255.0 standby ip 10.1.1.3 standby priority 99 router2 # show standby etherne T0/0-group 0 local state is standby, priority 99 hellotime 3 sec, holdtime 10 sec next hello sent in 1.014 virtual ip address is 10.1.1.3 configured active router is 10.1.1.1, priority 100 expires in 7.159 www.2cto.com standby router is local 4 state changes, last state change 00:02:02 router2 # When in privileged mode, you can use the show standby command to view the hsrp status. This command tells which vro is active, which is backed up, and many other statistics. On the pc, the default IP Address should point to 10.1.1.3 instead of one of the routers. In this way, if a router fails, the other router will take over. In addition, you can even use this redundancy to disable the active vro in the day, because the hsrp fault backup replacement time is less than 10 seconds. Hsrp is a useful tool to ensure high availability and router redundancy. Of course, there are also several hsrp options which we will not detail in this article. For more information, see the cisco hsrp faq.