Question about Subinterface in trunking a router on astick

You have multiple Vlan's, why? because you want to limit the broadcast domain.This means users in vlan 1 cannot send frames to users in vlan 2.If you want a device in vlan 1 to communicate with a device in vlan 2 you need a router.The router will look at layer 3 so therefore each vlan needs its own subnet address.So your router interface is divided into subinterfaces with different subnets corresponding to different vlans.If a remote router needs to
route to one of these subnets it will look in its routing table for the next hop router.So you can either use static routing or dynamic routing to adverise these routes.

Man you didn't answer my question, Do I need to advertise this subnet so other remote router knows about my subnet either static or dynamic
let say
vlan 2 to 4 are in subnet 32 64 and 96
and on my router it is configure on sub interface we called it ON A STICK.

the cidr I used is /27 that gives me block size of 32

I am using 2600 series
int e0
no ip address
no shut

int fa0/0.2
encapsulation dot1q 2
ip address 192.168.10.33 255.255.255.224

int fa0/0.3
encapsulation dot1q 3
ip address 192.168.10.65 255.255.255.224

int fa0/0.4
encapsulation dot1q 4
ip address 192.168.10.33 255.255.255.224

Serial 0 which is connected to another router
let say I am using RIP2 to advertise my subnet networks.
172.16.10.1 is my ip I used vlsm

Now again my question is Do i need to advetise my subinterface.

chinaman wrote:

Now again my question is Do i need to advetise my subinterface.

You dont advertise the subinterface,you advertise the networks attached to the subinterface.
I think you should reread my post.At the end i wrote "So you can either use static routing or dynamic routing to adverise these routes"
It looks like your missing out the foundations of routing if you ask such a question.How do you expect remote routers to know where the vlan subnets are if you dont advertise them or create static routes.

lwwarner

The fact that you are using vlans is irrelevant. Like any network, if you want it to be reachable from anywhere but the local router you have to advertise it via a routing protocol or create static routes on your other routers.

You are just confusing the issue by thinking that this has anything to do with vlans.

your right I am confused, that no ip address command confused me.
grr.... so I need to advertise that subnet networks assigned to my subinterface.

so if I have 3 subneted ip assigned in my fa0/0.2 to fa0/0.3 I need to advertised them.

eample
router rip
//this are my subinterface ip address assigned in vlan 2,3,4
network 192.168.10.33
network 192.168.10.65
network 192.168.10.97
// this is my serial0 ip address
172.16.10.1/30

Im sorry if I ask this stupid question,

RIP doesnt allow classless routing. You would use

router rip
network 192.168.10.0

That would advertise all networks in the 10 subnet. Remember you cannot have an IP on a physical interface when you are using subinterfaces (fa0/0.1 fa0/0.2...etc)

EDIT:

I believe it wouldn't advertise the .33,.65 ..etc because RIP doesnt support VLSM & CIDR...It's a classful routing protocol. I need to boot up a router and check that out.

Sorry I forgot to inform you that it should be rip2

grr...... I am messed up.

I see, so it is not allowed to assigned an ip address when using subinterface but how can I advertised this ip subinterface.

Sorry I forgot to inform you that it should be rip ver 2

grr...... I am messed up. and by the way thanks for the help

Ripv1 or Ripv2 doesnt matter,same as modemhumper has specified.RIPv2 can support vlsm but it is still configured with the classful network number.
By configuring network 192.168.10.0 all subnets belonging to this classful address will be advertised.

The fact that you are using vlans is irrelevant. Like any network, if you want it to be reachable from anywhere but the local router you have to advertise it via a routing protocol or create static routes on your other routers.

You are just confusing the issue by thinking that this has anything to do with vlans.

Read what lawwarner wrote..ANY network you want to advertise WHETHER it's a subinterface or a physical interface (doesn't matter) can be done with a static route or a dynamic routing protocol.

example with rip 1:

Three subinterfaces, networks 192.168.10.0,20.0 and 30.0

router rip
network 192.168.10.0
network 192.168.20.0
network 192.168.30.0

You are advertising these routes to all other routers in the internetwork. It's like saying "Hi I'm Jesse and I can be reached at 123 Apple Street".

Hi Jesse,im Ed gimme your phone number!

ed_the_lad wrote:

Hi Jesse,im Ed gimme your phone number!

Ok now Im scared

It's getting complicated and I am totally confused.

It's only simple question, Do I need to advertised my subninterface or not?

How should be my configuration like this
subinterface 0/0.2 = 33, 0/0.3 = 65, 0/0.4 = 97
and i used network 192.168.10.0

Router rip
version 2
network 192.168.10.0
network 172.16.10.0

So does my configuration will advertised the network 192.168.10.0
and 172.16.10.0?

gabrielbtoledo

Yes, that should do it. Unless you have more networks to advertise.

mikej412

ModemHumper wrote:

ed_the_lad wrote:

Hi Jesse,im Ed gimme your phone number!

Ok now Im scared

Why, are you Jesse? Or are you afraid that Ed will want to call you next?

mikej412 wrote:

ModemHumper wrote:

ed_the_lad wrote:

Hi Jesse,im Ed gimme your phone number!

Ok now Im scared

Why, are you Jesse? Or are you afraid that Ed will want to call you next?

lol, that he will call me!!!!

pizzafart

That bit about calling folks was pretty funny.

anyway,
Chinaman, your last post helped frame your question better because it included all the variables: the networks (e.g. 192.168.10.32), the subinterface numbers (e.g. 0/3.2), and the commands for the routing protocol (network 192.168.10.0).

You do NOT have to advertise the subinterface numbers in any way. Subinterface numbers are a syntax that's completely unrelated to IP addressing. Often someone will name a subinterface number to match a network (e.g. fa0/2.12

, but this is only to help keep track of things and has no technical relevance to routing or addressing.

You DO have to advertise the networks that you've assigned to each vlan (e.g. in your post you have the network 192.168.10.32 /27.) The routing commands that you've placed in your recent post look like they will do the job.

Hope this helps and good luck.

Thanks a lot. its clear to me now

I bought some ccna ref command and try to test it in the netsim 6, and I am so amaze that it works, however I am wondering what is the use of loopback in the confiuration.

Do I need to set up the default gateway on the switch or it will work without DG because on th host the DG is already set and it is diff on the DG of the SW.

I hope you got my idea.
Thanks a lot and wish me on 25 may for my exam