Virtual LANs (VLANs) are used to logically divide a single physical switch into multiple broadcast domains.
2
votes
3answers
134 views
Is a router always necessary to link two subnets?
I am thinking especially of VLANs, which represent separate subnets that may need only one switch.
0
votes
1answer
90 views
Practical uses for a new switch [closed]
Ok, I'm kind of a network newbie, at least from an enterprise perspective. Lots of theory and course work, little hands on. I've got a small two enclave network, and someone handed me an excess ...
6
votes
9answers
266 views
Locate a host on Network
What is the best method of locating a particular workstation on a VLAN ?
I sometimes need to do this, if a workstation IP address, shows up on an ACL Deny
torrent use
High bandwidth usage (Top ...
1
vote
1answer
103 views
tcpdump (-i any) with vlan
I have a question regarding tcpdump (capturing all interfaces) and a strange capture I see.
Environment:
2 Linux devices connected and configured with VLAN TAG (802.1q). I am pinging between the 2 ...
2
votes
4answers
93 views
Can a VLAN bridge be used to replace a bypass switch with an IPS device?
I am wondering if it's possible to set up a way to remove the need for a bypass switch when using an IPS device. To summarize, I would have an IPS device acting as a virtual wire on a connection I'm ...
3
votes
3answers
150 views
How to throttle speed for a particular computer with high activity?
We're in an office environment of about 50 people. A few departments send emails with large attachments extensively and doing so clogs up the WAN connection (10Mbps).
I'm upgrading the networking ...
2
votes
2answers
77 views
Super Aggregated VLAN vs. Q-in-Q
Is Super Aggregated VLANs Brocades version of Q-in-Q? If any, what are some of the major differences between SAV and Q-in-Q?
15
votes
3answers
293 views
Accidentally Removed Allowed VLANs from Cisco Switch Dot1Q Trunk
I am adding a new VLAN to an existing trunk port between two Cisco Catalyst switches (3750's). In the process of adding the new VLAN, it appears that I've removed the existing allowed VLANs on the ...
7
votes
3answers
247 views
VLAN and subnet relationship
Many have pointed out that a VLAN can hold one or more subnets. If your default gateway for this subnet is on a router or a L3 switch then how could there be more than one default gateway in a VLAN ...
2
votes
8answers
227 views
Trunk port or access port?
In a colo/DC environment, if you had a customer wanting to do their own VLANs & subnetting, would you configure the port going to their L3 switch as a trunk port or an access port?
12
votes
10answers
762 views
Difference between Subnet and VLAN?
You often hear the terms Subnet and VLAN used interchangeably. With the ubiquitous nature of IP these days, when are the two not considered roughly the same from a high-level, understanding that ...
10
votes
7answers
392 views
When *not* to create a SVI for a L2 VLAN?
When creating VLANs for just L2 on a switch -- routing will be handled by a device within that VLAN such as a load-balancer -- it isn't necessary to create the vlan interface. As a matter of habit, I ...
8
votes
7answers
664 views
Introductory level explanation of VLANs
What's the basic use case(s) for VLANs?
What are the basic design principles?
I'm looking for something like a two paragraph executive summary style answer so I can determine if I need to learn ...
4
votes
4answers
149 views
Are multiple links with different VLANs between two switches possible?
I'm not considering Etherchannel or LACP.
Given 2 Ethernet switches A and B, where both switches have port 0 configured as a tagged trunk for VLAN 100 and 101 and port 1 configured as a tagged trunk ...
15
votes
8answers
1k views
Easily deploying new VLANs in a large environment
How do people handle the need to add VLANs to all switches on their network (or even a subset of devices)? We are adding around 6 new VLANs per week at the moment and as the network grows this is ...
4
votes
1answer
53 views
Migrating from VLANs to MPLS on JunOS
I'd like to see a worked example of recreating a regular common VLAN based topology using MPLS on Juniper hardware. In particular we will be using EX3xxx and EX4xxx for swicthing, though I don't think ...
4
votes
3answers
163 views
Mac-flap due to roaming clients on wireless
We are running an Aerohove wireless network (controller-less).. I occasionally get mac-flaps within the VLAN tied to a SSID. I know this is coming from a roaming client.. The problem is that the ...
