- Community Home
- >
- Networking
- >
- Legacy
- >
- Switching and Routing
- >
- Question re: untagged/tagged VLANs across switches
Categories
Company
Local Language
Forums
Discussions
Forums
- Data Protection and Retention
- Entry Storage Systems
- Legacy
- Midrange and Enterprise Storage
- Storage Networking
- HPE Nimble Storage
Discussions
Forums
Discussions
Discussions
Discussions
Forums
Discussions
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
- BladeSystem Infrastructure and Application Solutions
- Appliance Servers
- Alpha Servers
- BackOffice Products
- Internet Products
- HPE 9000 and HPE e3000 Servers
- Networking
- Netservers
- Secure OS Software for Linux
- Server Management (Insight Manager 7)
- Windows Server 2003
- Operating System - Tru64 Unix
- ProLiant Deployment and Provisioning
- Linux-Based Community / Regional
- Microsoft System Center Integration
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Community
Resources
Forums
Blogs
- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Printer Friendly Page
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
10-28-2019 04:21 PM - edited 10-28-2019 04:25 PM
10-28-2019 04:21 PM - edited 10-28-2019 04:25 PM
Question re: untagged/tagged VLANs across switches
Hi Everyone
At the "Core" layer 2/3 switch, are uplink ports placed in their own 'untagged' port so they have their own IP range?
E.G. below are switch config for the Core Switch (located on Floor8
The floor 9 switch then connects to another switch on Floor 9 to accomodate more PCs, laptops etc.
See below, clarification would be greatly appreciated.
"Core" Layer2/3 Switch
hostname "Floor8-1"
ip route 0.0.0.0 0.0.0.0 <gateway IP>
ip routing
interface 46
name "Floor-8:46 uplink to Floor-9:48"
exit
interface 48
name "Floor-8 link to WAN Gateway"
exit
vlan 1
name "DEFAULT_VLAN"
no untagged 1-48
no ip address
exit
vlan 18
name "Data Floor 8"
untagged 1-45
ip address x.x.x.x 255.255.255.0
ip helper-address <DHCP Server>
exit
vlan 19
name "Data Floor 9"
untagged 46
ip address x.x.x.x 255.255.255.0
ip helper-address <DHCP Server>
exit
vlan 30
name "Voice"
tagged 1-47
ip address x.x.x.x 255.255.255.0
ip helper-address <DHCP Server>
qos priority 5
voice
exit
loop-protect 1-45
Floor 9 "Edge" Switch 1
hostname "Floor9-1"
interface 48
name "Floor9-1:48 downlink to Floor8-1:46"
exit
vlan 1
name "DEFAULT_VLAN"
no untagged 1-48
no ip address
exit
vlan 19
name "Data Floor 9"
untagged 1-48
ip address x.x.x.x 255.255.255.0
exit
vlan 30
name "Voice"
tagged 1-48
ip address x.x.x.x 255.255.255.0
qos priority 5
voice
exit
loop-protect 1-47 (don't loop protect uplinks)
Floor 9 "Edge" Switch 2 (linked to Edge switch 1)
hostname "Floor9-2"
vlan 1
name "DEFAULT_VLAN"
no untagged 1-24
no ip address
exit
vlan 19
name "Data Floor 9"
untagged 1-24
ip address x.x.x.x 255.255.255.0
exit
vlan 30
name "Voice"
tagged 1-24
ip address x.x.x.x 255.255.255.0
qos priority 5
voice
exit
loop-protect 1-23 (don't loop protect uplinks)
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
10-29-2019 12:11 AM - edited 10-29-2019 05:21 AM
10-29-2019 12:11 AM - edited 10-29-2019 05:21 AM
Re: Question re: untagged/tagged VLANs across switches
Since you loop-protect ports 1-47 on Floor 9 Switch 1 (so you don't only on down/up links dedicated ones)...where is the downlink port used to connect to Floor 9 Switch 2?
I'm not an HPE Employee

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
10-30-2019 04:47 PM
10-30-2019 04:47 PM
Re: Question re: untagged/tagged VLANs across switches
Hi Parnassus
RE: Since you loop-protect ports 1-47 on Floor 9 Switch 1 (so you don't only on down/up links dedicated ones)...where is the downlink port used to connect to Floor 9 Switch 2?
My mistake, On Floor 9, switch 1, downlink port is port 47 to Floor 9 switch 2 port 24, as I have a loop protect 1-46 in the updated switch configuration.
What still confuses me is Core 'hub' to 'Edge' switch VLAN scenarios where:
Core 'hub' is the Layer 2/ Layer 3 routing switch:
For any DATA VLANs we need to have one untagged port in each VLAN which has an IP Address and DHCP IP Helper then we TAG the outbound interfaces we want this VLAN to traverse?
Voice VLANs are always tagged (say 1-47)
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
05-06-2020 04:44 AM
05-06-2020 04:44 AM
Re: Question re: untagged/tagged VLANs across switches
@DoJu wrote: What still confuses me is Core 'hub' to 'Edge' switch VLAN scenarios where:Core 'hub' is the Layer 2/ Layer 3 routing switch:
For any DATA VLANs we need to have one untagged port in each VLAN which has an IP Address and DHCP IP Helper then we TAG the outbound interfaces we want this VLAN to traverse?
Voice VLANs are always tagged (say 1-47)
Well...basically, yes you need to have that.
Consider things that way: on a Layer 2 switch (generally at Edge level) access devices (hosts) are connected unaware of any VLAN tagging (their packets enters the Switch port untagged = without any tag), once packets enter the Switch port they are accepted/dropped in relation to VLAN tagging the port is configured with...let suppose a host is connected to an access port (so member of a single VLAN, generally called the native VLAN for that very port and also generally untagged)...the untagged packets enter the port member of the untagged native VLAN id x (PVID)...the packets are accepted and internally to the switch they become tagged with the VLAN id x...now you need to transport those packets where the routing between VLANs will happen...to the Core (Layer 3 = IP Routing enabled)...to do that you can transport those packets as untagged in VLAN id x when they leave the uplink port to the Core or, if you need to carry multiple VLAN ids on the same uplink (physical or logical, doesn't matter), you are forced to transport those packets as tagged in VLAN id x (along with other VLAN ids) when they leave the uplink port to the Core....clearly on the Core the downlink port connected to the Edge switch need to correctly received those untagged (or tagged) incoming packets (and, doing so, at the very same time they also send packets with the same VLAN tagging pattern...as it happens on the uplink port at Edge side)...internally to the Core the same things happening on the Edge switch will happen...up to the VLAN Interface (SVI) where the routing to other VLAN ids (with SVIs) will happen.
So if you look at a VLAN id you discover it could be "transported" across many devices (more correctly the involved uplink, downlink and access ports involved with the transport let the packet of a particular VLAN id to move across the network) moving packets between access ports and access/trunk ports (trunk ports generally is a term used to describe uplink/downlink ports to other peer switching or routing devices).
I'm not an HPE Employee
