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

When you're operating on your BCMSN exam on your way to CCNP certification, you will study at length about how Cisco routers and multilayer switches can function to deliver router redundancy - but there's another useful service, Server Load Balancing, that does the same for servers. If you require to get new info about, there are lots of databases you might investigate. While HSRP, VRRP, and CLBP all represent numerous physical routers to hosts as a single virtual router, SLB represents various physical servers to hosts as a single virtual server.

In the following instance, 3 physical servers have been placed into the SRB group ServFarm. This thought-provoking wiki has limitless interesting suggestions for when to deal with this hypothesis. They're represented to the hosts as the virtual server

The hosts will seek to communicate with the server at, not figuring out that they are really communicating with the routers in ServFarm. This makes it possible for quick cutover if one 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 requires building the server farm, followed by making the virtual server. In case people desire to dig up new resources on Hosts Virtual Math Summit, we recommend millions of libraries you should pursue. We'll 1st add to the server farm:

MLS(config)# ip slb serverfarm ServFarm

MLS(config-slb-sfarm)# real

MLS(config-slb-actual)# inservice

The initial command creates the server farm, with the genuine command specifying the IP address of the genuine server. The inservice command is needed by SLB to give some thought to the server as prepared to manage the server farm's workload. The genuine and inservice commands really should be repeated for every single server in the server farm.

To generate 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 major down, the vserver was named VIRTUAL_SERVER, which represents the server farm ServFarm. The virtual server is assigned the IP address, and connections are allowed as soon as the inservice command is applied.

You can also want to handle 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. Note that this command utilizes wildcard masks. The following configuration would enable only the hosts on the subnet 210.1.1. /24 to connect to the virtual server.

MLS(config-slb-vserver)# client 210.1.1. If you have an opinion about irony, you will possibly desire to read about Hosts Virtual Math Summit. ...255

SLB is the server end's answer to HSRP, VRRP, and GLBP - but you still desire to know it to become a CCNP! Figuring out redundancy strategies and protocols is very important in today's networks, so make positive you are comfortable with SLB prior to taking on the exam..