Router on stick in serie 800 router

[fcodiazj]

Good afternoon:

Run a simulation in packet tracer to implement a router on stick with two vlans. The simulation worked without problems, and I want to implement the same on my cisco 867VAE router.

This equipment has a Giga interface for WAN (Ge1), and four FastEthernet interfaces + 1 Giga interface (Ge0) for LAN, all of them in an integrated switch. I want to use the Giga LAN interface to manage the vlans, but the router won't let me create the necessary subinterfaces. After doing some research, I found this link which says that subinterfaces are only available for interfaces in router mode (https://community.cisco.com/t5/switching/cannot-access-subinterface-on-gigabit-ethernet-ports /td-p/4665192).
This brings me to the questions that I ask you to help me answer:

Is there any way to configure the cisco 867VAE router to use the Ge0 interface in router mode? (I don't need the other Fe interfaces)

In case of not being able to use the Ge0 interface in router mode, how do you suggest configuring the router to be able to manage the vlans? (Consider that the router is in charge of delivering IP addresses to each of the computers that connect to the vlans)

Thanks in advance for your time and help.

[MHM Cisco World]

why you need subinterface, 
you can use VLAN SVI and add as much as you want 

[fcodiazj]

I want to use subinterfaces because that was what I simulated in packet tracer, and it is what the literature indicates as the easiest and fastest way to solve my problem.

Since this solution didn't work, because it is implicitly confirmed that interfaces in switch mode do not have subinterfaces, I am just studying new possible solutions and their impact.

I thank you for your suggestion.

[Martin L]

867VAE router may not have such capability. try different router Or use 2 router interfaces

you can attach PT file here in zip format

Packet Tracer, aka PT from Cisco Net Academy, is just a software Simulator; it does not run on real IOS or virtual IOS; It is close to IOS but It does not really behave like real IOS would (some simply features do).
PT is excellent tool to learn and practice networking fundamentals and commands for CCNA exam.
Regards, ML
**Please Rate All Helpful Responses **

[paul driver]

Hello
Have you tried putting the interface in router mode?

int Ge0
no switchport

[paul driver]

Hello

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@fcodiazj wrote:

 I found this link which says that subinterfaces are only available for interfaces in router mode

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So the interface needs to be a routed interface (meaning it will have  ip address(s) assigned to them (physical ports /SVIs)
Sometimes you may need to disable the default L2 port so it becomes a L3 routed port as I have shown in my previous post.

[chrislemon12]

Interesting challenge with the 867VAE and trying to set it up for router-on-a-stick configuration. It seems like the limitation around subinterfaces is a tricky one. Have you considered any workarounds like using a different interface or a VLAN configuration that doesn't rely on subinterfaces? Would be great to hear if anyone's managed to configure VLANs on this model in a similar scenario.

[Tenni]

You're trying to set up VLANs on a Cisco 867VAE router but ran into a roadblock because they couldn't create subinterfaces on the LAN ports configured in switch mode. They initially tried simulating a setup using subinterfaces but found out it's not supported on their router model.

To work around this, they're considering configuring VLANs using Switch Virtual Interfaces (SVIs) on the integrated switch interface (Ge0). This method involves assigning IP addresses to each VLAN on the switch itself and configuring the router to route traffic between these VLANs. It's a different approach but should achieve their goal of segmenting the network into VLANs and allowing communication between them.

In short, while they can't use subinterfaces directly, configuring VLANs as SVIs on the switch interface should enable them to manage VLANs and handle routing effectively on their Cisco 867VAE router.

i'm facing this issue too

Here are some resources that I found and these may help you.
https://community.cisco.com/t5/routing/cisco-router-800-series-router-fe-wan-port-not-working/td-p/4969007
https://community.cisco.com/t5/routing/cisco-800-series-router-problems/td-p/4520518= https://apkloklok.net/
https://community.cisco.com/t5/routing/dhcp-with-router-on-a-stick-fails-instead-uses-apipa/td-p/5055070
https://community.cisco.com/t5/routing/class-map-match-any-not-working/td-p/1913558
https://community.cisco.com/t5/routing/router-on-a-stick-not-working/td-p/5021751 

[Joseph W. Doherty]

Subinterfaces only apply to routed interfaces.

To support router on a stick, using a switch port, you would configure it as a trunk port and use SVIs.

I don't recall whether the ISR switch ports support being trunks, but do recall they support SVIs.

Understand, logically, a router on a stick is implemented differently on a router vs. a L3 switch, but conceptionally they are the same.  Consider the downstream L2 switch configuration is the same for either.