VLAN and RIP Question.

Hi,

I'm on the VLAN and STP portion of my ICND2 studies and i have a few questions

Is it possible to use rip to advertise networks on subinterfaces?

Also how does VLAN work across a serial link or the "cloud"?

Say you have PCs in Vlan 10 'Sales' at the main office and some in a branch office. Maybe i'm thinking too hard about but would the data simply route across the serial link and/or 'cloud' with a proper routing protocol?

Would you have to set up 2 Routers-on-a-stick, one for the main office and one for the branch office? Because it would seem silly to have data from Vlan 10 on a branch office have to travel across a serial link and/or cloud to reach the Router-on-a-stick at the main office if the data was intended for a different VLAN at the branch office. (i probably answered my own question but i would still value input =D )

Oh ya and one last bonus question that i haven't had any study material explain yet. On a DCE side of a serial link why is it most examples you see set the bandwidth to 56000? What is the optimum Bandwidth X for a serial link?

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Comments

tomaifauchai

Dustin.cisco wrote: »

Is it possible to use rip to advertise networks on subinterfaces?

Yes

Dustin.cisco wrote: »

Also how does VLAN work across a serial link or the "cloud"?

Depends, but you don't really know what happen in the cloud. Last time i've deployed a point-to-point trunk over the cloud, they just said to me to put that interface into vlan1407. I suspect some QinQ design behind that

Dustin.cisco wrote: »

Say you have PCs in Vlan 10 'Sales' at the main office and some in a branch office. Maybe i'm thinking too hard about but would the data simply route across the serial link and/or 'cloud' with a proper routing protocol?

It work at layer 2, so if you have an end-to-end trunk between the main office and branch office, it'll send broadcast through the trunk

Dustin.cisco wrote: »

Oh ya and one last bonus question that i haven't had any study material explain yet. On a DCE side of a serial link why is it most examples you see set the bandwidth to 56000? What is the optimum Bandwidth X for a serial link?

It's just examples

WIC-1T 8192000 bps
WIC-2T 8192000 bps pert port
HWIC-4T 8192000 bps per port
NM-4T is a special case. (8192 bps maximum aggregate)

If 1 port is used
0 8192000
1 0
2 0
3 0

If 2 ports are used (for max data)
0 4096000
1 0
2 4096000
3 0

If 3 ports are used but max data on channel 0
0 4096000
1 0
2 2048000
3 2048000

Dustin.cisco

tomaifauchai wrote: »

Yes

Depends, but you don't really know what happen in the cloud. Last time i've deployed a point-to-point trunk over the cloud, they just said to me to put that interface into vlan1407. I suspect some QinQ design behind that

It work at layer 2, so if you have an end-to-end trunk between the main office and branch office, it'll send broadcast through the trunk

It's just examples

WIC-1T 8192000 bps
WIC-2T 8192000 bps pert port
HWIC-4T 8192000 bps per port
NM-4T is a special case. (8192 bps maximum aggregate)

If 1 port is used
0 8192000
1 0
2 0
3 0

If 2 ports are used (for max data)
0 4096000
1 0
2 4096000
3 0

If 3 ports are used but max data on channel 0
0 4096000
1 0
2 2048000
3 2048000

Thanks for the response!

So if i wanted to create a Trunk between a main office and a branch office over a WAN i would pretty much have to consult with the ISP on that matter?

tomaifauchai

Dustin.cisco wrote: »

Thanks for the response!

So if i wanted to create a Trunk between a main office and a branch office over a WAN i would pretty much have to consult with the ISP on that matter?

Obviously, it depends of your needs and your money

burbankmarc

Dustin.cisco wrote: »

Thanks for the response!

So if i wanted to create a Trunk between a main office and a branch office over a WAN i would pretty much have to consult with the ISP on that matter?

I wouldn't recommend it unless you have a 100mbps link. LAN traffic can be very chatty with all the broadcasts (especially windows).

mikej412

Dustin.cisco wrote: »

Also how does VLAN work across a serial link or the "cloud"?

As far as the CCNA goes, it doesn't. Each VLAN is it's own broadcast domain -- and routers separate your broadcast domains.

As far as the CCNA goes, you may have VLAN 10 for Sales at all your remote locations -- but they are going to be separate IP subnets (and broadcast domains) and you will rely on routing for all the Sales folks at different locations to talk to their shared resources and each other (if needed).

Using tunnels, bridging, or MPLS VPNs to extend the same layer 2 broadcast domain between multiple locations is beyond the scope of the CCNA.

Dustin.cisco

mikej412 wrote: »

As far as the CCNA goes, it doesn't. Each VLAN is it's own broadcast domain -- and routers separate your broadcast domains.

As far as the CCNA goes, you may have VLAN 10 for Sales at all your remote locations -- but they are going to be separate IP subnets (and broadcast domains) and you will rely on routing for all the Sales folks at different locations to talk to their shared resources and each other (if needed).

Using tunnels, bridging, or MPLS VPNs to extend the same layer 2 broadcast domain between multiple locations is beyond the scope of the CCNA.

I'm not looking at it from an Exam perspective. I will be working for a bank soon as their network admin and they have 5 branches including the main office. As far as i know the servers will be in the main office and when i begin to create vlans i was wondering how well would branch offices reach the servers across a WAN if they are in a different vlan.

Obviously i need to finish my CCNA studies to better answer that question myself but since the job is starting soon i feel the issue above will be an obstacle i'll have to over come.

networker050184

Dustin.cisco wrote: »

I'm not looking at it from an Exam perspective. I will be working for a bank soon as their network admin and they have 5 branches including the main office. As far as i know the servers will be in the main office and when i begin to create vlans i was wondering how well would branch offices reach the servers across a WAN if they are in a different vlan.

The traffic will be routed. You don't need the L2 domain to span the WAN unless there is a good reason for it.

Dustin.cisco

I wish GNS3 supported switches so i could test it out myself.

networker050184

Just use a router with one of the switching modules (NM-16ESW) in GNS3. That should have more than enough functionality for what you are looking into.

lon21

I didn't want to start a new thread as my question is on VLAN.

I could not sleep last night recapping what I learnt... trying to get my head round it.

I've been doing some lab from CBT videos.

I learnt from the start of the videos that we should always setup up a vlan interface to telnet to the switch.

As I been working through the videos I've forgotten to configure the vlan interface on routers but assigned ip address to the ports which I've been using e.g. fa0/0, fa 0/1 etc... I guess router don't have vlan interfaces right? unless its a router with switch ports?

Is I can assign ip address to each port on a router can I not to the same for a switch therefore no required to set up a vlan interface?

On a router I have assigned different ip address on each ports, I noticed that it was possible to configure the router by telnetting to any port on the router, is this ok to do? If so can this method also be applied to a switch (i.e. no vlan interface)?

Thanks

networker050184

lon21 wrote: »

As I been working through the videos I've forgotten to configure the vlan interface on routers but assigned ip address to the ports which I've been using e.g. fa0/0, fa 0/1 etc... I guess router don't have vlan interfaces right? unless its a router with switch ports?

Correct. Unless you are using a L3 switch then there are no VLANs on a router except for port based sub interfaces.

lon21 wrote: »

Is I can assign ip address to each port on a router can I not to the same for a switch therefore no required to set up a vlan interface?

Again only on a L3 switch that also acts as a router.

lon21 wrote: »

On a router I have assigned different ip address on each ports, I noticed that it was possible to configure the router by telnetting to any port on the router, is this ok to do? If so can this method also be applied to a switch (i.e. no vlan interface)?

Thanks

Best practice is to configure a loopback interface on the router and use that for management purposes. The loopback should remain the same address and will never go down unless the whole router is down.

Zartanasaurus

lon21 wrote: »

Is I can assign ip address to each port on a router can I not to the same for a switch therefore no required to set up a vlan interface?

You can assign different IPs to each port on an L3 switch, but the networks can't overlap. Therefore each host connected to the switch would have to be on its own subnet. It's not something you want to do with an access switch. Normally you'd have say, 20 PCs connected to the switch all on the VLAN with the SVI acting as the default gateway for that VLAN. T

lon21

In which case is it best practice to assign ip address on each interface on a switch or use vlans?

I know router dont have vlan in which case do you have to assign a ip address to each interface connected?

Thanks

SteveO86

You can not assign IP address to switch interfaces. (Unless it's a layer 3 switch and you issue the no switchport command on the desired interface) Assigning the IP address to the VLAN is best.

Routers the IP gets assigned on a per-interface basis.
Routers can have sub-interfaces to each VLAN and in which case the IP address would be assigned to each sub-interface.