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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39 views

Broadcast over all internet

Is it possible for someone to send an IP broadcast packet over all internet? I know that routers do not allow that, but is there any other way?
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2answers
2k 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 ...
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1answer
23 views

issue regarding broadcast mac address

I read a line saying {Routes do not forward packets coming from one interface having broadcast mac address (FF:FF:FF:FF:FF:FF)} what is meant by one interface in that line? if router cannot broadcast ...
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4answers
6k 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? ...
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5answers
59k views

pinging broadcast address

Iam using linux.I read somewhere in the internet that pinging the 255.255.255.255 will ping everyone in the network segment. And it will return every ip addresses in that subnet. but when i tried ...
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2answers
658 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 ...
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2answers
163 views

Unknown DHCP problem

Sometimes in my network I have some DHCP problem, the clients don't receive their IP. The problem seems connected with the switch because, for example, if I change the switch port of the client the ...
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4answers
3k 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
17 views

WiFi AP mode. Is AP bradcasting SSID all the time or when it receives the request from the station

WiFi AP mode. Is AP bradcasting SSID all the time or only when it receives the request from the station? I cant find the answer and maybe someone of you guys know the answer.
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4answers
13k 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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2answers
101 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 ...
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1answer
249 views

How do I set a display filter in wireshark that sorts by destination broadcast?

1 0.000000 Vmware_90:07:7b Broadcast ARP 60 Who has 192.168.185.144? Tell 192.168.185.7 27 0.995837 28.144.7.123 192.168.185.144 HTTP 1177 HTTP/1.1 200 OK (...
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1answer
81 views

Can modern network equipment handle very large broadcast domains

We operate a network where we have 'tons' of VM servers that are physically hosted on many many blade chassis. The thought behind the original design was to simply put them in one very large ...
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2answers
550 views

MAC address and unicast, multicast and broadcast

I'm very new to computer networking and I'm trying to figure out this dilemma about the Unicast, Multicast and Broadcast transmissions. I was told that MAC address are unique for each device and they ...
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1answer
224 views

Sending a gratuitous ARP on an interval - Cisco

In response to my question Propagating Static MAC Addresses , I realize I can not avoid the unknown unicast problem. Essentially I have hosts that forward their traffic via an L2 frame to a ...
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0answers
36 views

Issue with PIM-SSM Multicast Configuration ISR4431s

I have an issue with my PIM-SSM multicast configuration using ISR4431s.    I am wanting to forward broadcast data from an application from one VLAN in on the multicast source to another VLAN on a ...
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1answer
53 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 ...
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2answers
2k views

Broadcasting traffic by 255.255.255.255 or by “subnet dot all ones”?

If a device wants to broadcast traffic does it send it to the "all ones" IP? (Which is 255.255.255.255)? Or does it send it to "the all ones of the subnet"? (For example if the subnet is 123.123.0.0/...
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1answer
186 views

Where exactly is the limited broadcast address used?

I read that limited broadcast address will be dropped by the router. So, it's not used in the layer-3 (Network layer), where IP addresses are meant to be used. So, where exactly is it used?
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1answer
23 views

Juniper MX: NTP broadcast on two VRFs with the same addressing

In Juniper, NTP broadcast is set at system level, so two VRFs cannot use the same addressing and use NTP broadcast at the same time. Is there any alternative?
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5answers
3k views

WHY and HOW do routers and vlans break broadcast domains?

Everybody says routers (and vlans) break broadcast domains, but nobody goes into WHY that is, it seems. What's the router logic? Say I have three routers on my lan, with one main router and the ...
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2answers
610 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 ...
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1answer
69 views

Broadcast ICMP and gratuitous ARP

When sending an ICMP broadcast, all nodes can respond. is it the case of the sender too? If it's the case then: Is it specified somewhere that the sender should respond with gratuitous ARP when the ...
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0answers
19 views

Are network IP addresses ever used as source or destination IPs? [duplicate]

The first IP address of an IP subnet is the network address, which stands for the whole network, while the last address is the broadcast address. As far as I understand, we never really send packets ...
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1answer
33 views

Will DHCPRequest get ignored by other computers?

I've been reading about DHCP and see that it uses limited broadcast to send its initial request to reach a DHCP server. I read about limited broadcast too which says it sends the message to every ...
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2answers
57 views

Where are broadcast packages filtered out

When I have one network with a switch. Within that network I have 10 PC. Halve of them are configured within the 192.168.1.0/24 range and the other halve is configured at 192.168.2.0/24. This means I ...
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1answer
194 views

Broadcasting to unknown Class C Network

I am trying to use python to broadcast to my local network, and I cannot find a way to get the subnet mask. I have been suggested to use the default Class C network subnet mask 255.255.255.0, and use ...
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3answers
14k views

What is the difference between layer-2 and layer-3 broadcasts? Please explain with an example

What is the difference between broadcast addresses ff.ff.ff.ff.ff.ff (Layer 2) and 255.255.255.255 (Layer 3)?
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1answer
80 views

Is an IP broadcast always a layer 2 broadcast also

On my PC I see 255.255.255.255 in ARP with MAC FF:FF:FF:FF:FF:FF, so I'm assuming that in most cases the L3 broadcast is also encapsulated into an L2 broadcast frame, but is this standardized? For a ...
5
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1answer
167 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 ...
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3answers
14k 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
17k 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 ...
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0answers
20 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. ...
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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
1k 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, ...
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1answer
146 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
649 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
674 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
159 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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3answers
9k 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
40 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 ...
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1answer
329 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 ...
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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 ...
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4answers
1k 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 ...
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2answers
4k 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
230 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
473 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
122 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 ...
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1answer
100 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
325 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?