Inter-Vlan Communication b/w 2 switches

arsalan921

Hello Everyone,

i am new here, i want some help in inter-vlan communication b/w 2 switches.

i am using a simulator.

i have got 2 switches( 2960 ) and 1 router(2811).

connected 2 switches together over a trunk interface. Made two vlans ( vlan 2 and vlan 3 ) on each switch. vlan 2 and vlan3 on switch 1 and vlan 2 and vlan 3 on switch2.

routers one interface is connected to switch1 and other to switch2.

now inter-vlan communication happens on a single switch ( switch1) , vlan 2 is able to communicate with vlan 3 within a single switch,
how can i do inter-vlan communication b/w two switches ? i mean i want vlan 2 on switch1 to communicate with vlan 3 on switch2 ?
right now the configuration i have done is ,it allows vlan 2 of switch 1 to communicate with vlan 3 of same switch...

billscott92787

First of all, welcome to the forms



Secondly, can you please provide a little bit more information? Have you configured trunking between the switch and the router? Have you configured dot1q? I'm going to assume that you have since the VLANs can communicate between each other on the first switch. What happens when you try to ping a machine on a specific VLAN, from the other hosts on the other switch? I mean if you have set up the trunk link, it should be passing information between the switches.

captobvious

Read this - Configuring InterVLAN Routing and ISL/802.1Q Trunking on a Catalyst 2900XL/3500XL/2950 Switch Using an External Router

arsalan921

thank you BillScott and CaptObvious for your replies.

i have spent some time on it and i have been able to do it. i have made a few changes

router's interface fa 0/0 is connected to switch1. made two logical interfaces (because i have two vlans). one router interface interface fa 0/0.2 and interface fa 0/0.3 ...

switch1 is connected to switch2 over a trunk interface.
switch1 is connected to router over a trunk interface.
router has encapsulation dot1q configured.
removed switch2's connection to router. it is now only connected to switch1.
both the switches have two vlans ( vlan 2 and vlan 3).

and now vlan 2 of switch 1 can communicate with vlan 3 of switch 1 and switch 2 both..

one more change which i made is that when i made two logical interfaces on routers interface fasether 0/0, i made like interfa fa 0/0.2 and inter fa 0/0.3 , this 2 and 3 on interface numbers represent the vlan numbers, before i wrote randomly interface fa 0/0.4 and interface fa 0/0.5 ... this was one major problem because of which i was not able to do communication b/w two vlans. i dont know how this logical numbering has affected vlan communication because i read somewhere that this numbering doesnt matter, u can choose whatever number u want, but in my case it didnt work.

once again thank you both of you and captobvious i have opened the link which you gave and i find it useful, so gonna read it now.

billscott92787

Yeah,


What you did was configured router on a stick. The other method is the traditional method.


The difference being, the traditional method is to configure one interface PER VLAN. What does this mean? Well, it means a lot of interfaces, if you have a lot of VLANs. The other way (router-on-a-stick), you can do exactly like you did and configure one "logical" interface per VLAN.



I'm glad to see that you figured it out That is awesome troubleshooting skills and to be honest you will grasp things A LOT more by troubleshooting and figuring them out like you just did. Keep up the excellent work, and if you have any other questions, let me know

arsalan921

thank you BilScott,

I would like to know that in ccna exams, for lab questions do we have to use CLI or other tools such as SDM and CNA ( these are GUIs which are used for configuration purpose ), so for my ccna exam do i have to use these tools as well or should I be good at CLI only ?

one more thing in CCNA exam will i be given real cisco devices for configuration or will i be asked to do configuration on a simulator ?

rwwest7

arsalan921 wrote: »

thank you BilScott,

I would like to know that in ccna exams, for lab questions do we have to use CLI or other tools such as SDM and CNA ( these are GUIs which are used for configuration purpose ), so for my ccna exam do i have to use these tools as well or should I be good at CLI only ?

one more thing in CCNA exam will i be given real cisco devices for configuration or will i be asked to do configuration on a simulator ?

From what I've heard the CLI will be your friend.

Unless you have an L3 switch, then Router on a Stick is your best bet.

jmc012

arsalan921 wrote: »

thank you BilScott,

I would like to know that in ccna exams, for lab questions do we have to use CLI or other tools such as SDM and CNA ( these are GUIs which are used for configuration purpose ), so for my ccna exam do i have to use these tools as well or should I be good at CLI only ?

one more thing in CCNA exam will i be given real cisco devices for configuration or will i be asked to do configuration on a simulator ?

I don't recall seeing CNA on the CCNA blueprint, but the SDM and the CLI is in the blueprint for the exam so you need to know them very well. It is just a simulator on the test, but if you can practice with real equipment that is a good way to go.

billscott92787

Unfortunately I can't tell you anything that is on the exam. Anyone that does violates the NDA and can risk losing their certification. But, what I can tell you is the fact that if you are preparing for this certification, in the text you are using, I'm sure that they have examples of how to configure switches and routers via the CLI. IF the text shows you something, it is good to know it not only for preparation, but for the real world as well. Take a look at the cisco certification exam tutorial:

Cisco Certification Exam Tutorial - Cisco Systems

which can be found at the link above. This is going to give you a good idea of the "types" of questions, really the FORMAT of them that will be on the exams. As the previous poster mentioned, the CLI will be your friend, no matter if it is for preparation or real life. I mean you are studying to configure devices, trouble shoot them, and understand the theory behind all of this as well. You should be able to do all three. It will not only help you with your studies but it is going to benefit you in the long run as well.

mikej412

arsalan921 wrote: »

I would like to know that in ccna exams, for lab questions do we have to use CLI or other tools such as SDM and CNA ( these are GUIs which are used for configuration purpose ), so for my ccna exam do i have to use these tools as well or should I be good at CLI only?

Follow the links from the Cisco CCNA Certification web page to the Cisco Learning Network. You'll need to create a free login, but then you'll be able access the list of exam topics (the exam blueprints) that outline what you should know for the exam(s).

From the exam demo/tutorial you should have an idea about how a SIM may look -- it is a simulated environment within the exam. Since it is "graphical" they can program in a "web browser interface" as a well as the simple CLI command window shown in the demo.

arsalan921

thank you all of you for your replies.

i am using Packet Tracer 5.0 which i think is an excellent simulator, many switches and routers are available and its very easy to use. this simulator allows a device to be configured with CLI and there is one more way which i think is similar to SDM ( GUI way ) , has anyone used it ?

what simiulator you guys prefer ?
to use SDM i think we should have a real router or a switch connected to our pc's port ? what if we dont have real cisco equipment ? how can we practice SDM ?

is there any simulator available which has same look as real SDM ?

mikej412

Packet Tracer is getting better, but still doesn't let you do all the tasks you'd need to know for the CCNA. It's software from the Cisco Network Academy and students usually have access to real hardware in their Academy/School labs to supplement Packet Tracer. Packet Tracer is convenient for the Instructor to "assign homework" for a lot of the basics and helps reduce the initial competition for possible scarce lab hardware resources -- and give students something to play with while waiting for racks to open up.

SDM can be practiced using the real SDM software and Dynagen or GNS3. Dynagen is a character based front end for Dynamips, while GNS3 is a graphical version. Dynamips is a MIPS Processor Emulator that lets you run actual Cisco Router IOS images (with some hardware simulation and network communication/access added in). The only problem is that you need access to a supported IOS image file -- which is covered by a Cisco License Agreement (so no one here can tell you where to get one, other than to buy a router with a "good IOS" off eBay).

Blindhog.net has some videos about Dynagen, GNS3, and Dynamips -- and I think they have an SDM one too. Worth a look.

Also check out the resources at the Cisco Learning Network -- besides just the exam blueprints. Cisco has had some good stuff in the past, but it looks like they are making an even better effort with the new Learning Network.