Questions tagged [lan]

For questions about Local Area Networks (LANs).

Filter by
Sorted by
Tagged with
16
votes
8answers
32k views

What is real difference between host and node in network

According to wikipedia host is A network host is a computer or other device connected to a computer network. A network host may offer information resources, services, and applications to users or ...
15
votes
4answers
5k views

Why is the CAM table in a switch called CAM table and not MAC table even though it holds MAC addresses?

I know the CAM table in a switch holds MAC addresses and the ports that are associated with the respective MAC addresses. There are no such thing as CAM addresses from my knowledge, so why is it ...
8
votes
8answers
3k views

Can Ethernet frames only be transmitted in a LAN?

In the LAN depicted in the picture below, am I correct in saying that devices do not have IP addresses? There is no router and also only Ethernet frames (with source and destination mac address would ...
8
votes
2answers
16k views

IPv6 link-local vs unique local

When do you use link-local or unique local in IPv6 networks? (Cisco doesn't manage to explain it properly in their online material.)
8
votes
1answer
2k views

Cannot Load Internal Website over MPLS

We have an MPLS set up between two subnets. Everything (that is, I have RDP both directions as well as file-sharing) seems to be working correctly except for two things, which may be related. ...
7
votes
7answers
3k views

How LAN works in video games if only one station is permitted to transmit?

I've read the in a LAN the data is transmitted in packets so as to allow only one station to transmit at a given time, so how could this be applied in video games LAN parties if only one device is ...
7
votes
4answers
15k views

How to divide an IPv4 network into subnets of different sizes as efficiently as possible? [closed]

I need to divide a network 172.16.0.0/12 into 3 different subnets for different purposes. One of them needs 6 host addresses, another 85 host addresses and the last 100 host addresses. It should be ...
6
votes
2answers
15k views

Why we need IP address on LAN if switches can't read IP addresses

A beginner question: Why we need to assign IP addresses on LAN if switches are not able to read them? Because of ARP (Address Resolution Protocol)? But Switches can't send ARP requests (switches can't ...
6
votes
3answers
7k views

Is Ethernet a protocol?

When I googled I found a lot statements about this. Like.. Ethernet is not an application protocol. But I'd still give it the description "protocol". A network protocol defines rules and ...
6
votes
2answers
3k views

Why do LANs use MAC addressing instead of IP addressing?

Why do LANs use MAC addressing instead of IP addressing? In other words, why can't a network just assign an IP address to a local area network device and send the data to that, instead of the MAC ...
6
votes
1answer
1k views

How does priority work in token ring?

Token rings have an optional priority feature, for which the 8 access control bits in the token ring non-token frame are used. Suppose we are working with the delayed token reinsertion scheme. How ...
6
votes
3answers
1k views

Media Access Control for WAN protocols (equivalent to IEEE 802.3 Ethernet sublayer)

Ethernet can be divided into 2 sublayers; MAC and LLC. For WAN protocols like PPP, HDLC and frame relay, it is not discussed in regards to protocol sublayer for media access control. On serial ...
5
votes
5answers
189 views

How do two computers with different speeds communicate

This is one extremely basic and probably equally dumb question that I just couldn't ever find a definite answer to. Suppose we have 2 computers one that can transmit data at say 10 bits per second (A)...
5
votes
3answers
3k views

Why do we need MAC Address if we can uniquely identify each machine with an IP Address

I learnt that in ARP Protocol, to send a packet from one machine to another machine we need to know the MAC Address of the destination machine but since the destination has already been assigned a ...
5
votes
3answers
2k views

Why do we use VLAN?

According to my understanding, the network switch will look out for the specific MAC address and then it will forward the frame so basically it doesn't broadcast the frames then why do we make VLANs? ...
5
votes
2answers
1k views

Speed benefits when switching from 1Gb copper LAN to Fiber Optic

We are trying calculate how will the network performance improve when we switch from 1Gb copper LAN to Fiber Optic. We have 5-20 people simultaneously working on a Server via the 1Gb LAN. There are ...
5
votes
2answers
817 views

What precisely is a link?

When reading about layer 2 the word "link" is frequently used but strangely I'm struggling to find a formal definition of it. What is the precise definition of a link? So in the image below, how many ...
5
votes
2answers
8k views

Pfsense and two networks

I am playing around with pfsense and have an issue with it connecting properly to the internet. It has the 1 WAN port by default but I also want to run 2 other networks 192.168.3.0 and 192.168.4.0 on ...
5
votes
1answer
113 views

Industrial machines lose connectivity when one is powered off

I am working with 2 identical industrial machines with multiple Ethernet switches per machine. The basic layout looks like this: Switch 1 Machine A -> Switch 2 Machine A -> Switch 4 Machine A ...
5
votes
2answers
14k views

pfSense 2.3 How to setup each Lan traffic goes only over specific gateway

I am running a pfSense 2.3 box with 4 NICs. Now i have 2 different ISPs (one Cable & one DSL). How Can i configure, that all traffic from LAN1 goes ONLY over WAN1, and all traffic from LAN2 goes ...
5
votes
2answers
260 views

Bridging LAN networks privately in office environment

I've begun looking into network bridging, must most of it is witchcraft for me so far. I currently have the following setup: I use PC 1 as my development station and PC 2 as a deployment/test station....
4
votes
2answers
2k views

IP addresses from public IP block in my LAN

If I have NAT or PAT applied on edge router, Would it matter if I use IP addresses from public block in my LAN? And how?
4
votes
3answers
1k views

How is data sent from multiple different sources (computers) to the same destination host (computer) on a local network is handled by switch?

Let us say I have switch S, to which I have connected 4 hosts (A, B, C and D). Now let us say hosts A and B both want to send a series of data to the same host D at the same time. So here, A and B are ...
4
votes
2answers
1k views

How does Ethernet Switch ensures the validity of the MAC address table?

Let us say I have switch S with 4 ports, PA, PB, PC, and PD, to which I have connected 4 hosts, A, B, C and D with the MAC addresses AA:AA:AA:AA:AA:AA, BB:BB:BB:BB:BB:BB, CC:CC:CC:CC:CC:CC and DD:DD:...
4
votes
3answers
3k views

NEWBIE: How can two computers communicate if they are behind firewalls?

This is something I have wondered for awhile and couldn't find answer of. Apologies for the stupid question, but here it goes: If two computers have static IP's then they can easily send each other ...
4
votes
3answers
2k views

Error Detection across OSI layers confusion

Confusion: How does the transmitter know that his information( bits in physical layer, frames in data link layer, packet in network layer ) was transmitted correctly to the receiver? I know that in ...
4
votes
1answer
26k views

MikroTik - problem with port bridge over LAN using 2 switches [closed]

I have RB2011UiAS-2HnD-IN router in my network. It has two switches - "switch1" with 5 x 1Gb ports and "switch2" with 5 x 100Mb ports. There is only one LAN addressing pool - 192.168.1.0. All 5 ...
4
votes
2answers
2k views

How can multiple devices share an IP across the internet?

I do realize that most LANs sit behind a device running NAT, which translates the users private IP address to a public IP address. My question is still if you are trying to connect to a private device,...
4
votes
1answer
559 views

How are duplicate packets handled at the Data Link Layer?

Reading up about the data link layer I found that the logical link control sublayer uses sequence numbers to find duplicate packet frame transmissions. I understood the sequence number game with ...
4
votes
2answers
1k views

Full Duplex and Collision Domain

I have a very basic query on Collision Domain and Full Duplex Mode. There are two types of logical topology: Ethernet and Token Ring . Whenever we read about Ethernet the first thing that we are ...
4
votes
1answer
515 views

Network Diagram for IPv6 LAN

From what I understand about IPv6 networks, since NAT was a hack to deal with a lack of IP addresses in IPv4, NAT is a possibility, but not a requirement in an IPv6 LAN. So taking this into account,...
4
votes
2answers
1k views

Trouble Cascading VLANs Cisco Switches

Desperately I'm trying to cascade two Cisco SG200-26. The use case seems simple: No tagging should be needed, we just want each switch to behave exactly like two small switches. But just when ...
4
votes
2answers
2k views

Using a public IP for select hosts in a LAN

I have a small company and we just started out. Given our size, we really can't get a dedicated network guy for now. Recently, we moved to a lease line of our own for reliability. This is the ...
4
votes
1answer
72 views

Ensuring Network Stablity

I recently became the IT guy at a remote school with onsite staff. The network setup is a bit messy right now. I am curious about the best standards to use. Below is a map of the current network that ...
4
votes
1answer
2k views

New Ubiquiti EdgeRouter and UniFi AP - keeping networks separate but reachable

I've got a Ubiquiti EdgeRouter PoE (5 port) which I'm setting up just now. I'm trying to achieve a solution where the single UniFi AP can hand out IP addresses in the 10.0.2.0/23 space, while devices ...
4
votes
1answer
789 views

Is it possible to assign each vlan to a physical port on the ZyXEL USG40?

I'm trying to configure a ZyXEL USG40 to act as a switch that can physically separate 3 vlans from each other. I was told this product would be sufficient to setup a company network with 3 separate ...
3
votes
8answers
3k views

What is the “technical” definition of LAN and WAN

Most of explanations on internet contend by saying "lan" is over smaller distance, while "Wan" covers wider geography. To make question more clear ? If two computers are on the same "LAN" what is it ...
3
votes
3answers
534 views

Basic networking and DHCP theory

Background We're organizing an event where we need to connect about 10 PCs into a single LAN network (no internet access). We've got some general experience with "home" and "web" networking but we've ...
3
votes
3answers
2k views

Create LAN B, and use LAN A’s internet connection

I just rented a desk in an office. They have a LAN connected to the internet, and it’s shared among everyone in the (small) building. I have a few network devices I want to connect, but I don’t want ...
3
votes
2answers
37 views

LANs with no router,just a switch(or hub)

Can a LAN be implemented just with a switch? If so,how is the communication completed?just by MAC addresses? When sending a frame from the source to the destination,and inbetween there is a switch,...
3
votes
3answers
805 views

LAN QoS for VoIP

Is LAN QoS required for VoIP applications? We have basic network infrastructure: PC (Softphone) -GigEth-> [Switch] -GigEth-> [Router/Firewall] -> Internet (100 Mbps) -> [ITSP] Voice ...
3
votes
2answers
278 views

2 dhcp server with one pool

I want to know if there is an option to have two DHCP servers with one pool. The reason for this unorthodox is, I have two router in remote locations on the same LAN (10.0.0.0) And sometimes, the main ...
3
votes
1answer
5k views

Get MAC address of all devices (IP cameras) connected to switch

I am a beginner when it comes to networking, and I have done as much research as I can to try and figure this out on my own, but the more I read the more I realize I don't know. I work for a ...
3
votes
3answers
10k views

What are the reasons for not putting multiple subnets on the same VLAN?

I would like to know why we do not (and should not I guess) use 2 different networks on the same LAN/vLAN. From what I tried and understood : Host in network A (ex: 10.1.1.0/24) can talk to each ...
3
votes
1answer
122 views

Is datacenter a lan?

A datacenter can contains thousands of machines. At very high level is it just a LAN and private network with thousands of machines on them. Is datacenter a LAN ? or is it WAN ? Is datacenter a ...
3
votes
1answer
4k views

What devices are used to boost a UTP copper ethernet signal?

The signal at source is tolerable at a peak of 6 mb/s, but from the server room to other network switches in other buildings, figure a distance of say a football field, it's terrible. You can barely ...
3
votes
1answer
349 views

Change of IP address range

As part of a corporate project, I am responsible for changing the IP address range of remote sites. I will show you a theoretical scheme of the network and explain the details of the migration. My ...
3
votes
1answer
1k views

Spurious restransmission to a server behind pfsense NAT

i'm trying to connect to my ssh test server that i setup behind a pfsense firewall via nat on port 22. When I sniff packet on my laptop (WAN side of pfsense) trying to connect to the server, SYN is ...
3
votes
1answer
195 views

Assigning IPs for a LAN which is disconnected from the Internet (private network)

Lets say I want to set up a small packet-switching LAN using TCP/IP model with 10 hosts. If I do not intend to connect my network to the Internet, which implies that this is a private network and I ...
3
votes
2answers
71 views

Creating bandwidth with multiple WAN and LAN ports

I have a network with roughly 50 machines all on one LAN, consisting of Linux, Windows, and server machines. I have an untangled u150 firewall/router. I have the ability to add an additional WAN &...