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22

VLANs are a layer 2 construct, so they only exist on your local network and end at your router. The Internet has no concept of VLANs.


11

VLAN trunks as we know them from campus or enterprise networks cannot be extended "natively" across the Internet or any other routed network (see Ron Trunk's answer). Encapsulation/Tunneling is what can be done to make that possible: VXLAN, GRE, GENEVE, L2TP, MPLS-over-Ethernet... there's many a technology and protocol to support that (see Bobby Voychine's ...


6

Normally VLANs are only used within a site or at least within a network that is controlled by a single entity. It is possible, to carry encapsulated Ethernet traffic (potentially including VLAN headers) over an IP network using a variety of tunneling protocols and it is sometimes done. The problem is that to do so efficiently requires the "underlay" ...


4

There are a few approaches that you might take if you want to transfer L2 traffic over the internet. One way is with something called Layer 2 Tunnelling Protocol Version 3 or L2TPv3 for short. Layer 2 Tunneling Protocol Version 3 is an IETF standard related to L2TP that can be used as an alternative protocol to Multi-protocol Label Switching (MPLS) for ...


4

Unmanaged switches generally don't support VLANs - Cisco sells those, too, like the 110 Series switches (or the previous 100 Series, also they've got very small, unmanaged switches).


4

There's no discrepancy between VLANs and IP subnets - they go hand in hand. Organizing your network into different IP subnets enables you to provide a (security) structure and to limit the size of each broadcast domain (instead of having a single large one). Without VLANs, subnetting requires separate switches for each subnet and separate cabling for each ...


4

VLANs segregate a shared link-layer (L2) topology into smaller broadcast domains. CSMA/CD is the physical-layer (L1) access method for half-duplex Ethernet, normally only used with repeaters, hubs, or ancient Ethernet variants. Practically, it isn't even supported with current gigabit-and-faster variants any more. Since VLANs can only (reasonably) be used ...


3

Short answer: you don't need any VLANs if you use proper routing VLANs are used to segregate different kinds of traffic or security zones on an otherwise shared L2 network in each site. However, forwarding between sites is done on the network layer (L3), ie. by IP addresses. Normally, you have a 1:1 mapping between VLANs and IP subnets and each local ...


3

As Zac67 has already said, if you don't send tagged frames to those switches, they'll happily go about the job of switching traffic. However, if you send tagged traffic to a switch that hasn't been configured for it, anything can happen. "Does not support" does not always mean "does not understand". There are a lot of unmanaged switches built using hardware ...


3

You are not advertising the VLANs to other routers because they are not part of the OSPF domain. The OSPF configuration defines which interfaces are included in OSPF (i.e. the domain). You have only included the links between the routers, so that is all that OSPF will advertise. To make this work, create network statements in the OSPF section that ...


3

You did not configure NAT for your Private-to-Public addressing, so your packets will be dropped on the public Internet. The ISPs have agreed not to route packets with Private addressing. Unfortunately, I'm not completely sure how to do that on your Adtran device. The syntax appears similar to Cisco IOS, but there are a few differences, so I do not know if ...


2

All vendors currently use VLAN tagging according to the IEEE 802.1Q standard. Apart from ancient devices using proprietary protocols, all interoperate nicely. For things to work correctly, tagged links (VLAN trunks) must be configured in exactly the same way one both sides - one VLAN may remain untagged (sometimes called the native VLAN), all other must be ...


2

There is no problem other than each brand of switch will use different commands (and different terminology) to configure VLANs. To connect multiple VLANs between switches, all modern switches use the same IEEE 802.1q format, which mean they will interoperate with each other. Again, the only potential problem is the terminology and procedures used by ...


2

You can mix VLAN switches and non-VLAN switches in a network under the premise that none of the non-VLAN switches ever sees a tagged frame (which it doesn't understand). For instance you could have VLAN switches and trunks in the network cener and use non-VLAN access switches where there's only a single VLAN to be serviced. You'd configure the downlink ...


1

Basically, there's no performance difference in routing through a single interface or through multiple interfaces, unless there's a bottleneck in the hardware. Up to gigabit, a software router should be OK (assuming it's adequately powered). However, I'd use a dual-port NIC just for the sake of a clean division between LAN and WAN.


1

If the echo request doesn't even leave the source, there's no connection (common broadcast domain) between the source and its default gateway - the ARP request for the gateway fails and that's that. Use show mac address-table on each switch in turn to make sure that the switch sees both the source and the gateway in the desired VLAN. Also make sure that ...


1

There's absolutely no problem to have networks with multi-vendor hardware. Just be careful with proprietary protocols like EIGRP.


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