Questions tagged [broadcast]

For questions about broadcasting in computer networking. Use this tag when you are troubleshooting or configuring network devices in relation to broadcast.

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5
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1answer
126 views

Getting lot of unwanted broadcasts on my network

I am pretty new in Networking (noob), while I was monitoring my network using Wireshark, and I found that there is a lot of broadcasts happening all over the network, broadcast on Local network ...
3
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3answers
11k views

What are real life examples of broadcast and multicast?

In broadcast routing, packets are sent to all nodes even if they do not want it. What is a real life example of "broadcast"? Almost everything I can think of, like GMail and YouTube, appears to be ...
4
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1answer
15k views

How do VLANs affect the broadcast domain?

I'm repeating a "LAN Switching and Wireless" module in college and I'm looking over past exam papers in preparation for the repeat exam. One of the questions is What is a broadcast domain? Using an ...
2
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1answer
18k views

Why can't devices in different subnets talk with each other?

I know that the layer 2 doesn't understand IP, and the broadcast domain is same. Why can't devices talk, how does it happen?
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0answers
17 views

How to calculate subnet mask including, network address, gateway, broadcast address and host range? [duplicate]

You are defining network boundaries within a /24 network of 172.30.20.0/24. Please complete the segmentation of the /24 to account for multiple smaller networks of 115, 50, 28, 12, and 5 hosts. ...
0
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2answers
459 views

Wake-On-Lan (WOL) from WAN does not work with Unifi (USG/Switch)

tl;dr I need WOL over the internet over the USG to work. WOL works already locally. I guess the USG/Switch is the problem. Hi all As a newcomer to networking in general and Unifi in particular I am ...
16
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4answers
5k views

Why is 10.1.255.255 an invalid broadcast address?

I’ve been following the CCENT official certification book(100-105) and came upon this question in the “do I know this already?” quiz. The books only covered /24 subnetting only so far. Which of the ...
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3answers
613 views

Doesn't a router stop broadcast?

Well I was at work. And one of our customers connected a new device to that router. Additionally a switch was already connected to the router. So there was only the switch connected to the router, ...
-1
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1answer
159 views

How the broadcast MAC address accomplished?

The Layer 2 broadcast is the destination address of the Layer 2 package is FF-FF-FF-FF-FF-FF. I have a question about the broadcast MAC address. you see the ARP request, it send the destination MAC ...
5
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3answers
8k views

What is the difference between broadcasting and flooding?

In Open shortest path first routing algorithm, the information about connected links is "flooded" throughout the network. How is flooding different from broadcasting?
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1answer
93 views

Will this network diagram cause broadcast storms?

I have three VLANs, and I want to communicate between them, but all packets are dropped. I made a trunk to allow all VLANs. Should I use STP to control broadcast storms?
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1answer
210 views

ccna: Collision domain vs broadcast domain [closed]

I am currently preparing for CCNA I have a screenshot of CCNA online test. I don't remember if I got it right or not. I think there are 2 broadcast domain (circle with hand on the picture) and 5 ...
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3answers
501 views

Broadcasting and ARP packet

Router does not send Broadcast packet. that means it does not support broadcasting. but while sending packet from computer a to computer b which is not in the same network , computer a gets the mac ...
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0answers
68 views

very strange broadcast in LAN with Cisco ASA

Today i have detected Cisco ASA 5505 CPU usage went to 100% and LAN was flood with broadcast (ff:ff:ff:ff:ff) going to 10.0.12.255 address, i have noticed all these activity in wireshark that some ...
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2answers
71 views

is it ideal for a network that abandon the use of L2 switch?

I'm thinking about minimizing network hardware while optimizing network topology for company. If a company has unlimited(or very high) budget to build an ideal network for internal use(traditional ...
1
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1answer
27 views

Sending Broadcasting Frames after sending Unicast Frames

Absolute newbie here guys, I was reading the compTIA Network+ guide by Mike Meyers, and a section reads: "The frame propagates down the wire into the central box. The switch sends unicast frames to ...
2
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3answers
2k views

Do routers forward broadcast traffic?

Consider a host on 10.0.0.0/24 sending a packet to 10.0.0.255 and 10.255.255.255. In the first case all hosts on his subnet should recieve the packets but would the entire network receive the packet ...
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2answers
34 views

Hierarchical issue of Broadcasting on different subnets

I've got a problem that I can't seem to understand. 192.168.255.0 /24 is a valid network address. The broadcast address for this network is 192.168.255.255. 192.168.0.0 /16 is a valid network ...
1
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1answer
238 views

Flooding vs Unknown Unicast Flooding

Can someone clarify what is the difference between Flooding and Unknown Unicast Flooding? Is it the same thing or it contains different meaning? I'm aware that Flooding happens when a switch ...
3
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4answers
2k views

Prevent network auto-discovery between members of VLAN

At our ISP's we use Huawei s5300 switches, and we want to upgrade our setup to accomplish the following: Place a number of different customers/users under same VLAN. Assign one static-public IP ...
2
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4answers
836 views

Reducing broadcast traffic on Cisco SG300

I have a Cisco SG300 Small business switch, and the GUI interface is creating a lot of broadcast traffic: Source IP (The GUI IP): 172.16.xx.254:5353, Destination IP (Broadcast) 224.0.0.251:5353 I ...
5
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2answers
3k views

Does a switch MAC address table sync across all switches in the same VLAN?

Ok, I have read up about this 16K limit for the MAC address table, or better known as the CAM table, on certain switches. Lets say I have 14 different edge switches with that 16K limit, and I have ...
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1answer
124 views

Permit IP Directed Broadcast on DELL FTOS

OK so in cisco land you can add an acl to the ip directed broadcas command, but this option does not appear in FTOS (Dell Networking OS 9) if you enable ip directed broadcast on the vlan and then ...
2
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1answer
60 views

Defining what type of casting based on IPv4 address

I'm kinda new to networking. I have a small question, how can I determine what type of casting (unicast, multicast or broadcast) is it based on IPv4 address. For example: 142.55.172.200 I tried to ...
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1answer
66 views

Dhcp Broadcast Through Switches

Think of a pc connected to switch1. Sw1 is connected to sw2(trunk port on both switches) and sw2 is connected to a router(dhcp server). Pc sends a dhcp broadcast. Does sw1 passes the broadcast through ...
2
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1answer
81 views

DHCP Broadcast on SVI

Think of a dhcp broadcast going through multiple switches. What happens to that broadcast when it reaches the vlan interface (svi)?
2
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1answer
153 views

Broadcast domains switches

If I connect 3 computers to the same switch and used one of the PC's to ping another PC on the switch will this cause a broadcast domain as they are connected to the same switch?
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1answer
53 views

What practical concerns led to the use of multicast?

Answers to a question on SF explain the differences between broadcast and multicast. It is not clear yet for me which practical concerns brought in the usage of multicast. My understanding is that, ...
2
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2answers
2k views

What is the difference between MAC and İP broadcast addresses?

As far as I know, they are both used to send a packet to all hosts that are connected to a local arena network. Why would anyone need two addresses to send a broadcast package?
2
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2answers
557 views

Is the real broadcasting on internet possible

Am sorry if my question is silly. But I want to clear that i doesn't mean just playing audio or video from a remote server.I am asking about conventional broadcasting as exists in Television and Radio ...
3
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1answer
297 views

Must a broadcast request come from the same network?

I was reading about Smurf Attacks and how Smurf Amplifier Registry keeps track of servers used for amplifying the attack, then I wondered, can a request coming from anywhere broadcast it to all parts ...
3
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1answer
45 views

Ability to monitor all broadcast domains

Example: Network of company A has 5 VLANs: Accounting, IT, Guests, Servers, Board. All VLANs has DHCP servers enabled in their own VLANs. I am monitoring a single VLAN for DHCP packets by connecting ...
3
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1answer
2k views

Breaking broadcast domain through VLAN and Router

Why do we need to create VLANs to break a broadcast domain when the router can do the same? 1.Breaking broadcast domain through VLAN- Breaking broadcast domain through Router-
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2answers
2k views

How far is VLAN broadcast propagated?

I'm not 100% sure of the vocabulary, so please bear with me. Suppose I've set up some new VLANs to better divide my network logically. I have a 4507 as a core network switch with VLANs 1 and 10-19. ...
14
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3answers
31k views

How broadcasting works on different networks?

I was reading DHCP ( RFC 2131 ), I have basic knowledge about Relay Agent and Broadcasting. But for Understanding DHCP in depth, I felt like I have to know Broadcasting and Relay Agent ( RFC 1542 ) in ...
2
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1answer
48 views

Do the intermediate nodes learn a MAC address in ARP?

my doubt is about the ARP protocol. I know the procedure: if a host wants to know the MAC address of another sends a broadcast frame and the destination answers with its MAC. However, if an ...
3
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1answer
1k views

Why are DHCP ACK and REQ messages broadcast in Link Layer?

When I look at the protocol, I see that DHCP Request and Acknowledgement are both broadcast in the link layer. However at that point, both sides actually know each other's MAC addresses. Why do they ...
0
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1answer
49 views

What happen if broadcast is made to first and last address of other network?

Broadcast to network id What happens if you broadcast to the first IP of another network ? broadcast to broadcast id of another network What happens if you broadcast to the last IP of another ...
2
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1answer
57 views

Network discovery and establishing connections within Eduroam, a network split in subnets

For our current project we are supposed to create a peer2peer (no server) game application which is played by a teacher and his students on the Eduroam network. The concerns of the stakeholder ...
7
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0answers
389 views

How to control unwanted UDP traffic (Broadcast & Multicast) on Cisco Router 2911?

Please suggest, we are getting UDP traffic either broadcast or multicast in router 2911 which cause 95%+ utilisation of the router. And we got error in link and business impact due to this. Company ...
5
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3answers
3k 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? ...
7
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2answers
446 views

How is the Groupwise Transient Key used in WiFi networks?

In Wifi WPA, I understand that during association, a 802.11 client and AP negotiate a Pairwise Transient Key (PTK), using which the Groupwise Transient Key(GTK) is provided to the station. I ...
3
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2answers
609 views

Does WiFi broadcast traffic from a station go through the access point?

Let's say I've got two devices connected to my Access Point, a laptop and a tablet. If the laptop sends unicast traffic to the tablet, I understand that it must go through the AP. However, how is ...
2
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2answers
46 views

Can Multicasting be duplicated by broadcasting on a subnet?

Is there any functional difference between: A) Broadcasting to a range of addresses B) Putting the range of addresses into a subnet and broadcasting to that subnet Would it matter if there was a ...
3
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1answer
696 views

What is WDS and how can it cause a broadcast storm?

Recently I was told that we leave WDS off ,whenever we can, where I work. It was explained to me that a broadcast storm is created when a routers' broadcast gets back to itself, perpetuates itself and ...
0
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1answer
657 views

Setting MAC source address to broadcast

How would a network behave if one were to set the source address of an Ethernet frame to the broadcast address FF:FF:FF:FF:FF:FF? Obviously, one would have to manually alter the relevant field in the ...
3
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2answers
102 views

How does frequency-division multiplexing deal with overlaps?

As I understand it, FDM uses separate frequency for each channel, thus A will transmit data, for instance, every two seconds and B every three seconds. But, what will be delivered on the wire in the ...
2
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3answers
2k views

Is Ethernet a broadcast or point-to-point protocol?

Theoretically speaking, as far as I know Ethernet was developed to be used as a broadcasting protocol and technology. I guess nowadays it is not being used this way. Since ALL the examples I see refer ...
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1answer
2k views

IPTV Cisco configuration for C2960

I have attached a network diagram explaining IPTV network , i have below queries to understand & configure IPTV . All ports on edge switches are configured as access ports in VLAN 101. On Core &...
6
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3answers
830 views

Why couldn't a nework address be used as as broadcast address as well?

I am taking a refresher on Networking and I found out that: Network address is an IP address with all 0s after the subnet mask Broadcast address is an IP address with all 1s after the subnet mask ...