Native Vlans on Router (RoS)

rogue2shadow

Specific Question:
For the life of me I just can't seem to understand how addressing is done on management vlans leading to routers in a router on a stick config.

For reference this is integration 6.5.1 in the InterVLAN routing chapter of CCNA Exploration 3 (Cisco Net academy). I get a 98% completion but the last item remaining is "Native VLAN" for R1 itself.

Should vlan 1 have an address? How would you set a native vlan on a router?

In general:
This probably doesn't make sense and I am going to look at the Odom and Network Warrior books but I was wondering if anyone had an easy explanation of how vlan 1 works and what its significance is in intervlan routing.

notgoing2fail

If you are doing intervlan routing. Then all you need on the switches are the vlans to be created.

The ROAS, the router, will have the IP addressing for each VLAN.

Trunk the router between the switch and you got yourself inter-vlan routing.

By default, VLAN 1 is always created, it cannot be deleted, and is the designated native vlan.

I know this may not fully answer your question but we can start here.

Let me know if this helps.

dairou18

The command syntax is a little different for configuring the native VLAN. The most probable reason is because IEEE 802.1Q doesn't tag frames associated with VLAN 1. So the command to set it up might look a little something like this:

Interface fa0/0.1
encapsulation dot1q 1 native
ip address ...... .......

Hopefully this helps, unless I'm totally wrong and just made it worse for you.

rogue2shadow

dairou18 wrote: »

The command syntax is a little different for configuring the native VLAN. The most probable reason is because IEEE 802.1Q doesn't tag frames associated with VLAN 1. So the command to set it up might look a little something like this:

Interface fa0/0.1
encapsulation dot1q 1 native
ip address ...... .......

Hopefully this helps, unless I'm totally wrong and just made it worse for you.

I think that might just be it!

@notgoingtofail
I needed that too :P. I know security wise people say to change your management VLAN from 1 to another one due to default settings being naturally weak. I guess the way the lab put the addressing scheme, it just seemed kind of weird going back and forth between VLSM and non-VLSM schemes. ie. VLAN 99 was on 172.17.99.1 and other vlans were on 172.17.10.1, 172.17.20.1, etc.

str2

this is hilarious- i have a 98% on lab 6.5.1 just like rogue2shadow so i start searching the internet for a solution and dairou18 answers it perfectly with dot1q 99 native. thank you !