10-03-2023 05:38 AM - last edited on 10-04-2023 01:03 AM by Translator
Hi.
Instead of a
vlans with a router-on-a-stick
configuration, can one achieve the same connectivity result without vlans-- can one simply create on a
router port: sub-interfaces with ip-addresses in each subnet, and thus allow inter-subnet connectivity?
If not, why not?
Thank you.
Solved! Go to Solution.
10-03-2023 07:21 AM - last edited on 10-04-2023 03:36 AM by Translator
The problem you would have is the subinterfaces normally have some way to identify "their" traffic, such as a
VLAN tag, frame-relay DLCI, ATM PVC, etc.
You could, though, have different interfaces connect to the same L2 domain, each supporting a different network.
You could also have multiple networks on a single interface using secondary addressing but there are "issues" with the latter.
10-03-2023 05:44 AM - last edited on 10-04-2023 03:30 AM by Translator
How will they have communication if you do not have
vlan
tagging, how you identified where the packet from and where this need to go.
Other method you can do VRF ? (that totally different over engineering to solve simple solution).
10-03-2023 05:53 AM - last edited on 10-04-2023 03:32 AM by Translator
Thanks for the reply.
My thinking is that workstation GREEN from 10.0.1.0/24 connects to an L2 switch that connects to a router. Workstation RED from 10.0.2.0/24 connects to same switch. When each communication traverses from the switch to the router, because each
router sub-interface
is in a different subnet, it works.
Where is my understanding incorrect?
Thanks.
10-03-2023 06:22 AM - last edited on 10-04-2023 03:33 AM by Translator
SW-R
Use one link for each
vlan
Here you dont need
subinterface
config in R
10-03-2023 06:28 AM
GREEN is Different broadcas domain and RED is different BROACAST domain in Layer 2 point of view.
To bridge between the Layer 2 domain, you need Router to route the the traffic in appropriate way.
better explanation : (dont want to invent wheel again)
https://www.ciscopress.com/articles/article.asp?p=2990405&seqNum=2
10-03-2023 06:43 AM - last edited on 10-04-2023 03:35 AM by Translator
This is not production question, this is theoretical question.
It's different L2 broadcast domain only if there are
vlans
. It is same L2 broadcast domain if there are no
vlans.
so as asked...
Workstation GREEN from 10.0.1.0/24 connects to an L2 switch that connects to a router. Workstation RED from 10.0.2.0/24 connects to same switch. When each communication traverses from the switch to the router, because each
router sub-interface
is in a different subnet, it works.
Where is my understanding incorrect?
10-03-2023 07:21 AM - last edited on 10-04-2023 03:36 AM by Translator
The problem you would have is the subinterfaces normally have some way to identify "their" traffic, such as a
VLAN tag, frame-relay DLCI, ATM PVC, etc.
You could, though, have different interfaces connect to the same L2 domain, each supporting a different network.
You could also have multiple networks on a single interface using secondary addressing but there are "issues" with the latter.
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