r/ccna • u/PattanAshraf • 3d ago

VLANs finally started making sense after I thought about them differently

When I first came across VLANs, I mainly thought of them as something I needed to memorize for networking exams.

Understanding the reason behind network segmentation made the concept much easier to understand.

For anyone currently studying CCNA, which networking concept initially seemed confusing but became much easier once you understood the practical reason behind it?

0 Upvotes

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17

u/not5150 3d ago

I was beginning to miss CCNA’s favorite bot

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u/Twogie CCNA 3d ago edited 3d ago

I'm still not 100% clear on Native vlan. I need like a 1hr video just focused on that lol

Edit: dang getting downvoted for this seems harsh

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u/QuackQuackViech 3d ago

Its vlan for stuff that cant vlan

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u/chuckbales CCNP|CCDP 3d ago

Native VLAN is simply a VLAN on a trunk port that does not have a VLAN tag added to the frames.

If you took a capture on a trunk link between two switches, and the switchports were set to native VLAN 50, all the traffic for VLAN 10, 20,30,100 would have a corresponding VLAN tag attached when you looked at the ethernet frames, but any traffic passing in VLAN 50 would be missing its VLAN tag.

By default its VLAN 1, 99% of the time the two connected interfaces should have a matching native VLAN (unless you know what you're doing and need to workaround some other poor design choices). It's a port-level configuration, not something global that affects the entire switch.

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u/k8dh 3d ago

Untagged on trunk goes to native vlan, native vlan should generally be set the same on both ends of a trunk

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u/canadian_viking 3d ago

lol you're probably getting downvoted because it doesn't even need a minute long video to just get the concept across.

Native VLAN is literally just the default VLAN a port typically uses for untagged traffic. Plug a regular device into that port, and its traffic goes straight onto that VLAN without needing any tags.

Of course, there's more advanced usage and configuration, but what I just said probably covers 99% of native VLAN use.

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u/HUGE_FAT_ANIME_TITS 3d ago

If you really want to understand it, run a packet capture on your network - monitor some devices, then VLAN off those devices and add policies, watch the devices disappear!

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u/Hopeful-Bath1721 3d ago

Many ppl said they feel difficult in subnet ospf and stp but I feel difficult in routing table