For CCNA and CCNP candidates, it’s challenging never to chortle The very first time you listen to the phrase “router on the stick”. Permit’s experience it, that’s a pretty foolish term. But as anyone who has passed the CCNA and CCNP exams know, this is a very important exam subject matter that you choose to will have to know how to configure and troubleshoot.
Simple Cisco concept states that for hosts in different VLANs to speak, a Layer three unit have to be included to handle the routing among the VLANs. That unit is a router, and you'll find Specific issues that have to be taken under consideration for the two the Bodily router itself and the configuration you’ll be creating.
The router will probably be linked to a swap by way of a FastEthernet port (or increased). The router port cannot be an everyday Ethernet port, Because the router port will require the opportunity to send out and get knowledge simultaneously.
The configuration of the interface is where by matters get exciting. Let’s say Now we have two VLANs that should be making use of router-on-a-adhere to communicate.
Here's the VLAN data:
VLAN 20: 20.20.20.0 /24
VLAN 40: forty.40.40.0 /24
The port on the change that will be connected to the router’s FastEthernet port needs to be in trunking method, and you have to know the trunking protocol in use. We’ll go Along with the Cisco-proprietary ISL below.
The Actual physical FE port within the router will not likely have an IP handle. The use of router-on-a-stick mandates the use of reasonable subinterfaces. When we don’t have to use the VLAN figures for that subinterface quantities, I’ve located this assists you keep the interfaces straight. Just one subinterface should be given an IP deal with in VLAN 20, and https://en.search.wordpress.com/?src=organic&q=토토사이트 one other could have an IP tackle in VLAN 40.
Soon after developing subinterfaces rapidly 0.twenty and rapidly 0.forty, the config looks like this:
interface fastethernet0
no ip handle
interface FastEthernet 0.20
ip handle 20.twenty.20.one 255.255.255.0
interface FastEthernet 0.40
ip tackle forty.forty.forty.one 255.255.255.0
Contrary to popular belief, you’re Pretty much completed! Now we need the encapsulation assertion underneath each subinterface. The subinterface assertion should mirror equally the VLAN quantity as well as the 메이저사이트 encapsulation style getting used. When we’re finished, the config would appear to be this:
no ip deal with
ip deal with 20.twenty.twenty.one 255.255.255.0
encapsulation isl 20
ip deal with forty.40.forty.one 255.255.255.0
encapsulation isl 40
And that’s it! Your hosts in VLAN twenty really should now manage to talk to hosts in VLAN 40, and vice versa.
A number of remaining troubleshooting details – the most typical error with router-on-a-adhere is To place the wrong vlan number within the encapsulation statement. Also, you should definitely have configured the router’s IP address in VLAN twenty given that the default gateway for hosts in VLAN 20, and do the identical for VLAN forty.
I hope you’ve appreciated this look at router-on-a-adhere. While the title may get yourself a chuckle out of you, it’s even now used in Plenty of networks on the market, and being aware of ways to configure and troubleshoot it will get you that A great deal nearer to earning your CCNA and CCNP.