Questions tagged [vlan]
For questions about Virtual LANs (VLANs) which are used to divide what otherwise would be a single OSI layer-2 broadcast domain into multiple, logical OSI layer-2 broadcast domains.
1,281 questions
3 votes
2 answers
354 views
Can I perform inter-VLAN routing on a Layer 3 switch using a single trunk cable connected to an unmanaged Layer 2 switch?
My scenario: I have many endpoints currently connected to an unmanaged switch. I want to add Layer 3 switch and segment the network into VLANs, but I'd like to avoid the manual work of tracing which ...
- 41
0 votes
1 answer
119 views
Vlan on Stormshield PB
I'm coming to this forum because after a lot of research and testing, I'm unable to set up a VLAN solution on a Stormshield SN 510. Regarding my infrastructure, a router providing internet access and ...
- 3
1 vote
1 answer
66 views
Design question to fetch L2 traffic with sFlow
I need some advice about L2 traffic fetching. Here's the situation : I got 2 datacenters where both core switch (Cisco Nexus9000 C93240) are linked each other through a 1GB/s vPC where our VLANs are ...
- 111
0 votes
1 answer
91 views
M-LAG: After migrating the VLAN, network accessibility is limited to one switch
colleagues. I am solving the task of migrating several VLANs from MikroTik to a newly deployed core network, built from two Huawei CE6863E switches combined using M-LAG. Objective: remove all internal ...
6 votes
3 answers
375 views
Cisco Catalyst Switch: Trunk Configuration Not Allowing Communication with multiple VLANs
I have a Cisco Catalyst Ethernet switch. I would like to setup this configuration: Ports 18 and 19 are on VLAN 10. Ports 20 and 21 are on VLAN 20. I would like port 22 to have access to both VLANs 10 ...
- 163
4 votes
3 answers
377 views
MTU size on physical and logical port in OSPF
A single physical interface has multiple sub-interfaces (VLAN interfaces). These sub-interfaces are configured with IP addresses and OSPF. The MTU of the physical interface has been increased, but the ...
- 671
2 votes
1 answer
246 views
Management VLAN
You can see the topology in the picture below. I’ve configured the management VLAN on the switch to be VLAN 999 to separate the management traffic from user traffic. I’ve also configured SVI 999 with ...
1 vote
1 answer
256 views
What are the extra 4 bytes (00 00 00 00) on a 1500 byte ICMP echo reply after a juniper router upgrade?
After a juniper router upgrade we started having MTU problems. I'm no longer able to send the router a 1500 byte ICMP packet (on a direct attached subnet with vlan) and get a reply. If I adjust the ...
- 11
1 vote
2 answers
289 views
How VLAN helps in a scenario where different people in different places who are “logically” tied together
My Understand of VLAN's Purpose Say you manage network for a building which leases each floor to a company. You want to separate each company on each floor to its own LAN network for better security ...
- 159
0 votes
0 answers
69 views
VoIP Phone isn't getting DHCP after disconnecting the SD-WAN
My network was as follow : MPLS --> VeloCloud(SD-WAN) --> Meraki MX100 --> Cisco SF350 I removed the VeloCloud and MPLS and got a Modem from ATT and now my network look like this: ATT Modem --...
- 101
0 votes
1 answer
74 views
Packet loss between Host B and Router, but no packet loss between Host B and Host A or Host A and Router [closed]
I'm troubleshooting a packet loss issue with my IT department and am all out of ideas. I currently have the layer 2 folks blaming the layer 3 folks and vice versa - I'm just the guy caught in the ...
- 333
0 votes
1 answer
159 views
Multiple VLANs on a single interface and isolation
The issue I am facing is as follows: I have a (hypothetical) switch in Physical Location 1, and another in Physical Location 2. Physical Location 1 switch is connected to ISP (1gbe), nearby server A (...
- 1
1 vote
1 answer
82 views
Cisco inter-vlan routing with several routers
I am trying to enable inter-vlan routing, but something is certainly not working. Each of the computers is assigned to corresponding vlans, every switch-to-switch and switch-to-router link is ...
- 11
1 vote
3 answers
675 views
VLAN Configuration without inter-vlan routing but with Internet access
I’m trying to set up multiple VLANs on my Cisco Catalyst 3850 switch and connect them to the internet using a TP-Link AX20/Asus RT-N12 router. I need this setup to have multiple isolated networks with ...
- 113
2 votes
1 answer
158 views
Routing packages on the same subnet segment
A network topology question. I have a router running OpenWrt, with several VLANs (all working correctly) with 192.168.X.2 addresses, with X being a subnet corresponding to each VLAN. There is one DHCP ...
- 121