CCNP Certification / BCMSN Exam Tutorial: Server Load Balancing (SLB)
Once you’re focusing on your BCMSN Test on your solution to CCNP certification, you’ll study at duration about how Cisco routers and multilayer switches can operate to supply router redundancy – but there’s One more handy provider, Server Load Balancing, that does the identical for servers. Although HSRP, VRRP, and CLBP all represent numerous physical routers to hosts as a single Digital router, SLB represents several Bodily servers to hosts as one virtual server.
In the next illustration, a few physical servers have already been put to the SRB team ServFarm. They’re represented on the hosts given that the Digital server 210.one.one.fourteen.
The hosts will request to communicate with the server at 210.1.one.14, not being aware of they’re essentially communicating with the routers in ServFarm. This enables rapid cutover if one of the Actual physical servers goes down, and likewise serves to cover the actual IP addresses of the servers in ServFarm.
The basic functions of SLB requires generating the server farm, followed by making the virtual server. We’ll very first increase 210.1.1.eleven to your server farm:
MLS(config)# ip slb serverfarm ServFarm
MLS(config-slb-sfarm)# genuine 210.one.1.11
MLS(config-slb-actual)# inservice
The main command results in the server farm, with the real command specifying the IP address of the actual server. The inservice command is needed by SLB to think about the server as Completely ready to manage the server farm’s workload. The actual and inservice instructions really should be recurring for every server from the server farm.
To generate the Digital server:
MLS(config)# ip slb vserver VIRTUAL_SERVER
MLS(config-slb-vserver)# serverfarm ServFarm
MLS(config-slb-vserver)# Digital 210.1.1.14
MLS(config-slb-vserver)# inservice
Within the prime down, the vserver was named VIRTUAL_SERVER, which signifies the server farm ServFarm. The Digital server is assigned the IP deal with 210.one.one.14, and connections are allowed as soon as the inservice command is utilized.
You might also want to regulate which within your network hosts can hook up with the virtual server. If hosts or subnets are named with the shopper command, These will be the only consumers that may connect with the virtual server. Be aware this command works by using wildcard masks. The following configuration would let just the hosts on the subnet 210.1.1.0 /24 to connect to the virtual server.
MLS(config-slb-vserver)# client 210.one.1.0 0.0.0.255
SLB is definitely the server conclude’s response to HSRP, VRRP, and GLBP – but you continue to need to realize it to become a CCNP! Realizing redundancy approaches and protocols is important in currently’s networks, so ensure that you’re at ease with SLB ahead of taking on the exam.