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.

Filter by
Sorted by
Tagged with
0
votes
2answers
146 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
votes
4answers
4k 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 ...
5
votes
1answer
103 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 ...
-1
votes
1answer
92 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 ...
0
votes
1answer
88 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?
-1
votes
1answer
133 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 ...
0
votes
0answers
20 views

How is it possible to create 6 subnets? [duplicate]

The following task presents me with an insurmountable obstacle... Given is the following: IP: 192.168.40.0 Subnetmask: 255.255.252.0 Task: Form 6 subnets over this network and enter ...
2
votes
0answers
55 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 ...
-2
votes
2answers
70 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
vote
1answer
25 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
votes
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 ...
0
votes
2answers
32 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
vote
1answer
223 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 ...
1
vote
1answer
111 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
votes
1answer
47 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 ...
1
vote
1answer
56 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
votes
1answer
67 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
votes
1answer
127 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?
1
vote
1answer
50 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, ...
3
votes
1answer
40 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 ...
2
votes
1answer
44 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 ...
0
votes
1answer
48 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
votes
1answer
55 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
votes
0answers
339 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 ...
7
votes
2answers
429 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
votes
2answers
524 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
votes
2answers
45 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
votes
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
votes
1answer
581 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 ...
2
votes
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 ...
6
votes
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 ...
0
votes
1answer
43 views

Users broadcasting who they are in WLAN and cell-phone networks

In the same way that wifi-enabled devices and wireless APs broadcast their MAC addresses (FF:FF:FF:FF:FF:FF), do cell-phones/smartphones also broadcast such an ID too to connect to a cell tower? That ...
0
votes
1answer
186 views

Physical layer broadcast address and network layer broadcast address [duplicate]

For example here is an ip address: ip address:192.168.0.205 subnet mask:255.255.0.0 broadcast address:192.168.255.255 network address:192.168.0.0 My question is what does 192.168.255.255 do and ...
2
votes
1answer
498 views

Unable to enable “Directed broadcast” on router in packet tracer?

I have a topology like below, wherein 2 subnets with address 192.168.0.0/24 and 192.168.1.0/24 are connected to a single router, Router0. Now i want to send a directed broadcast from PC0 on subnet ...
5
votes
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. ...
0
votes
1answer
117 views

Udp broadcasting for communicate with a device who has the same IP address , is it possible?

I was thinking about broadcasting in an ad-hoc local area network, then i asked me a question.Assuming that this LAN is made of 2 pc, if this pc have the same IP address, Can i send udp packet from ...
3
votes
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-
1
vote
1answer
70 views

Where do I need to assign the network address and the broadcast address

I'm about to take the second CCNA module exam and I have to configure routers and switches, but I can't understand something. So let's say i have this IP with this mask and i have to subnet, and you ...
1
vote
1answer
207 views

Does other hosts “learn” mac-ip entries on broadcast

in this post Learn MAC addresses via replies to other hosts requests I see that if host A sends an ARP query about host B, host C that resides in the same LAN will not learn host B MAC address, but ...
2
votes
3answers
110 views

Does a dial-up modem support multiple users?

Since I have never worked with a dial-up modem, I was wondering if it created an internet connection for only one user, a point-to-point connection, or if it also supported multiple users.
1
vote
3answers
519 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, ...
5
votes
2answers
385 views

Can a broadcast storm do physical damage to computers and networking hardware?

We had a broadcast storm that went undiagnosed for several hours. After the problem switch was unplugged and traffic returned to normal, we had a handful of machines and switches that were broken. On ...
5
votes
1answer
5k views

When and where to use Spanning-Tree (Portfast)

The tl;dr, in which scenario (switch-to-host, or switch-to-switch) do I use spanning-tree portfast or spanning-tree ...? We had a catastrophic network outage today. My first question to my boss was "...
1
vote
1answer
73 views

Routing between network 1 and subnet of network 2 And their broadcast address

Suppose there's a network A with network 10.0.0.0 with network id=10.0.0.0 and Broadcast address 10.255.255.255 and Mask = 255.0.0.0 and network B with network 197.10.3.0 with network id =197.10.3.0 ...
3
votes
2answers
515 views

Can a large broadcast domain break accesspoints

I have a network with a large class B broadcast domain (172.16.0.0/18 - 172.16.192.0/18) with a single DHCP server. I have lots of L2 switches in this network but there is no VLAN configured. My ...
2
votes
2answers
2k views

Is there any difference between Limited Broadcasting and Directed Broadcasting when used in same network

I understand that limited broadcasting happens locally and can be done by using destination address as 255.255.255.255. The directed broadcasting happens across networks. To be precise, i want to ...
1
vote
1answer
586 views

Broadcast storm generation

Recently I managed to trigger storm control the university end-point I was using (they told me it triggers at 10% bandwidth broadcast traffic). The end-point had a switch plugged in, the switch had a ...
2
votes
1answer
413 views

How does broadcast work in cable networks?

Sorry for the long post. I tried to make it small but couldn't make it any smaller. Any help would be really appreciated. It would be great if you can explain from the basics. In the book "Computer ...
1
vote
1answer
457 views

Why does OSPF use flooding instead of broadcasting?

In flooding, we send unicast/multicast frames to all the routers in the network, whereas in broadcasting, we have a broadcast address by which we send packets to all the routers. In OSPF, "Router ...
1
vote
3answers
1k views

How to minimize broadcast-traffic in a multi-ap wireless network?

For example let's take a University's wireless network for the students or a Wifi in a Hotel: There are many wirelss devices that are causing broadcast traffic. In theory: Is there any way to ...