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Today, I could finally understand well how native vlans work.
I& #39;ll try to explain it and share the way I felt when I could get it.
https://abs.twimg.com/emoji/v2/... draggable="false" alt="🤪" title="Zany face" aria-label="Emoji: Zany face">https://abs.twimg.com/emoji/v2/... draggable="false" alt="🥳" title="Partying face" aria-label="Emoji: Partying face">
#ccna #packettracer #networks
I& #39;ll try to explain it and share the way I felt when I could get it.
#ccna #packettracer #networks
First off, native vlans are used to forward untagged frames between switches, this tag usually is refered to VLAN IDs in trunk links. In the image, the "tag": 802.1q "encapsulation" is shown. To me, the term "extra-bytes-adding" applies better :v
By default, native vlan is configured in vlan 1; however, it may lead to security vulnerabilities and less efficiency due to some protocols must be untagged such as DTP or STP and in a trunk, the vlan id tag is added. So, to change native vlan from vlan 1 is a best practive
Let& #39;s show as a magic trick :3. First, we have that topology. We& #39;ll communicate vlan 11 terminals (with a ping). The native vlan is set by default, it is to say: vlan 1
192.168.2.2 is pinging to 192.168.2.1 (ICMP frame). Here, the message just left the switch, so, we& #39;ll see whats behing https://abs.twimg.com/emoji/v2/... draggable="false" alt="👀" title="Eyes" aria-label="Emoji: Eyes">
" title="192.168.2.2 is pinging to 192.168.2.1 (ICMP frame). Here, the message just left the switch, so, we& #39;ll see whats behing https://abs.twimg.com/emoji/v2/... draggable="false" alt="👀" title="Eyes" aria-label="Emoji: Eyes">" class="img-responsive" style="max-width:100%;"/>
as mentioned previously, the native vlan default is set in vlan 1, so in the trunk process, the frame will be tagged with 802.1q...extra bytes added in the ethernet frame...and there they are!!!!!!! https://abs.twimg.com/emoji/v2/... draggable="false" alt="🔎" title="Right-pointing magnifying glass" aria-label="Emoji: Right-pointing magnifying glass">
" title="as mentioned previously, the native vlan default is set in vlan 1, so in the trunk process, the frame will be tagged with 802.1q...extra bytes added in the ethernet frame...and there they are!!!!!!! https://abs.twimg.com/emoji/v2/... draggable="false" alt="🔎" title="Right-pointing magnifying glass" aria-label="Emoji: Right-pointing magnifying glass">" class="img-responsive" style="max-width:100%;"/>
By saying some magic words:
switch(config-if)# switchport trunk native vlan 11
https://abs.twimg.com/emoji/v2/... draggable="false" alt="🌟" title="Glowing star" aria-label="Emoji: Glowing star">https://abs.twimg.com/emoji/v2/... draggable="false" alt="✨" title="Sparkles" aria-label="Emoji: Sparkles">
(it should be applied in both switches in order to avoid mismatch problems)
...
switch(config-if)# switchport trunk native vlan 11
(it should be applied in both switches in order to avoid mismatch problems)
...
ta daaa: the tag is goneee
as the native vlan was applied to vlan 11, it stops encapsulating and just let the frames flowhttps://abs.twimg.com/emoji/v2/... draggable="false" alt="🍃" title="Leaf fluttering in wind" aria-label="Emoji: Leaf fluttering in wind">https://abs.twimg.com/emoji/v2/... draggable="false" alt="🌊" title="Water wave" aria-label="Emoji: Water wave">
as the native vlan was applied to vlan 11, it stops encapsulating and just let the frames flow
https://abs.twimg.com/emoji/v2/... draggable="false" alt="🌊" title="Water wave" aria-label="Emoji: Water wave">" title="ta daaa: the tag is goneeeas the native vlan was applied to vlan 11, it stops encapsulating and just let the frames flow https://abs.twimg.com/emoji/v2/... draggable="false" alt="🍃" title="Leaf fluttering in wind" aria-label="Emoji: Leaf fluttering in wind">https://abs.twimg.com/emoji/v2/... draggable="false" alt="🌊" title="Water wave" aria-label="Emoji: Water wave">">
https://abs.twimg.com/emoji/v2/... draggable="false" alt="🌊" title="Water wave" aria-label="Emoji: Water wave">" title="ta daaa: the tag is goneeeas the native vlan was applied to vlan 11, it stops encapsulating and just let the frames flow https://abs.twimg.com/emoji/v2/... draggable="false" alt="🍃" title="Leaf fluttering in wind" aria-label="Emoji: Leaf fluttering in wind">https://abs.twimg.com/emoji/v2/... draggable="false" alt="🌊" title="Water wave" aria-label="Emoji: Water wave">">
summarizing:
- native vlans let untagged traffic flow freely through trunking,
- it is a best practice to change native vlan from vlan 1,
- both switches must match native vlan conf
I might regret this thread later or maybe see how lame it is :v but now I& #39;m happy sharing ithttps://abs.twimg.com/emoji/v2/... draggable="false" alt="🤩" title="Star-struck" aria-label="Emoji: Star-struck">
- native vlans let untagged traffic flow freely through trunking,
- it is a best practice to change native vlan from vlan 1,
- both switches must match native vlan conf
I might regret this thread later or maybe see how lame it is :v but now I& #39;m happy sharing it
" title="summarizing:- native vlans let untagged traffic flow freely through trunking,- it is a best practice to change native vlan from vlan 1,- both switches must match native vlan confI might regret this thread later or maybe see how lame it is :v but now I& #39;m happy sharing it https://abs.twimg.com/emoji/v2/... draggable="false" alt="🤩" title="Star-struck" aria-label="Emoji: Star-struck">" class="img-responsive" style="max-width:100%;"/>
