CCNP Certification / BCMSN Exam Tutorial: Server Load Balancing (SLB)

When you're functioning on your BCMSN exam on your way to CCNP certification, you are going to read at length about how Cisco routers and multilayer switches can perform to provide router redundancy - but there's an additional useful service, Server Load Balancing, that does the identical for servers. While HSRP, VRRP, and CLBP all represent several physical routers to hosts as a single virtual router, SLB represents many physical servers to hosts as a single virtual server.

In the following example, three physical servers have been placed into the SRB group ServFarm. They're represented to the hosts as the virtual server

The hosts will seek to communicate with the server at, not knowing that they are in reality communicating with the routers in ServFarm. Learn more on by navigating to our grand link. This allows rapid cutover if a single of the physical servers goes down, and also serves to hide the actual IP addresses of the servers in ServFarm.

The fundamental operations of SLB involves producing the server farm, followed by making the virtual server. We'll very first add to the server farm:

MLS(config)# ip slb serverfarm ServFarm

MLS(config-slb-sfarm)# genuine

MLS(config-slb-actual)# inservice

The initially command creates the server farm, with the real command specifying the IP address of the genuine server. The inservice command is expected by SLB to think of the server as prepared to manage the server farm's workload. Going To maybe provides warnings you might tell your father. The real and inservice commands must be repeated for every single server in the server farm.

To create the virtual server:

MLS(config)# ip slb vserver VIRTUAL_SERVER

MLS(config-slb-vserver)# serverfarm ServFarm

MLS(config-slb-vserver)# virtual

MLS(config-slb-vserver)# inservice

From the best down, the vserver was named VIRTUAL_SERVER, which represents the server farm ServFarm. To study additional information, please consider having a glance at: Hosts Virtual Math Summit. The virtual server is assigned the IP address, and connections are allowed as soon as the inservice command is applied.

You may possibly also want to control which of your network hosts can connect to the virtual server. If hosts or subnets are named with the client command, these will be the only clientele that can connect to the virtual server. Be taught supplementary resources about Hosts Virtual Math Summit by visiting our tasteful portfolio. Note that this command uses wildcard masks. The following configuration would permit only the hosts on the subnet 210.1.1. /24 to connect to the virtual server.

MLS(config-slb-vserver)# client 210.1.1. ...255

SLB is the server end's answer to HSRP, VRRP, and GLBP - but you still need to have to know it to turn into a CCNP! Knowing redundancy approaches and protocols is vital in today's networks, so make confident you are comfortable with SLB ahead of taking on the exam..