Questions tagged [multicast]

For questions about multicast communications and protocols.

Filter by
Sorted by
Tagged with
2
votes
2answers
600 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 ...
1
vote
2answers
868 views

Multicast on the Internet

In 2016, is IP multicast still a thing not to rely on with IPv4? Is the only alternative still to duplicate packets? Context: This question is related to P2Peers (plural) topology, with one sender and ...
2
votes
2answers
185 views

Using as many multicast groups as transmitting devices

We have a set of ~40 embedded devices, each one equipped with a wifi module. All the devices are connected to the same wireless network. All the devices send packets to the same "master" computer. ...
4
votes
3answers
10k views

Inter-switch IGMP on a VLAN with two switches, and a multicast source per switch

I have a network consisting of two HP 2810 switched. Attached to each switch is, on one port, a multicast video coder, and on a different port, a decoder. There are two VLANs - a control VLAN (...
1
vote
1answer
219 views

How much influence does multicast and IPv6 have on latency?

I am looking for a fast and a diverse library for my game engine network. I have searched for a while, and I decided to use a simple one because of being fast to understand. I saw there are better ...
1
vote
1answer
1k views

HPE 1920-8G-PoE+ multicast filtering

I have a switch HPE 1920-8G-PoE+ that is connected to two computers and two access points: Ubiquiti UniFi AP-Pro n450. The access points receive data from many devices. The two computers send UDP ...
1
vote
2answers
361 views

Seeing traffic not addressed to me using tcpdump, how does that work?

I did a tcpdump capture, and when inspecting the reults, I saw some data I couldn't understand. Say the hostname of the box I did the capture on was box1.blah I saw traffic like this: box2.blah:...
6
votes
2answers
2k views

How is Multicast IP mapped to Multicast Mac address?

My main concern is why is the address 01-00-5E- and how? Especially 5 and E??
4
votes
1answer
5k views

What is the difference between source based tree and shared core based tree?

In case of multicast routing, I encountered source based tree and shared cost based tree.What is the difference between source based tree and shared core based tree? In which case they are used? what ...
2
votes
2answers
2k views

Multicast doesn't get forwarded correctly [closed]

I have a problem with UDP-Multicast with Kubernetes: I have to Kubernetes-Nodes each of them running a pod: Kubernetes-Node-1: - eth0: 192.168.0.2/24 - docker0: 10.1.1.1/24 Pod1 on Kubernetes-...
2
votes
2answers
257 views

Are there limits to the number of global IPv6 multicast addresses in use at a time?

The address space for IPv6 multicast addresses is very large (something like 2^112) and so I'm imagining it might not be so hard to get my hands on a million or so of them at some point, and try using ...
3
votes
1answer
7k views

config pimd on Linux to forward incoming multicast packet to OpenVPN tunnel interface

Does anyone know how could I setup pimd on Linux so that multicast address from 225.0.30.30 could route to 172.24.0.66/30 router on the right? So this is the lab I just setup today, In the lab ...
3
votes
2answers
1k views

Quagga (Zebra) multiprotocol BGP configuration for IP multicast routing

Host A: Eth1 = Multicast incoming from upstream provider OpenVPN_interface_point_A = point to point interface with point B ASN = 100 Host B: OpenVPN_interface_point_B = point to point interface ...
3
votes
0answers
1k views

How do switches behave on multicast? [closed]

I am benchmarking multicast throughput of my LAN using an application that considers all the servers as group members. The network consists of homogeneous servers (S0-S9: 192.168.21.70-79) inter-...
2
votes
1answer
135 views

what happens to multicast outside of the RP domain in PIM-SM?

Imagine you have a ring of routers, all of which are routing multicast with PIM Sparse mode, pretend there's a single Rendevouz Point (RP) "Router A" for any multicast on 239.10.10.0/24. If a stream ...
1
vote
0answers
245 views

EIGRP adjacency “forward” through DMVPN router not supporting EIGRP [closed]

I have a Cisco 819 with 4G which is a "spoke" and has a layer 3 DMVPN connection to the "hub." This (C819HG-4G-V-K9) router does not support EIGRP, therefore I cannot establish adjacency to the DMVPN ...
1
vote
2answers
106 views

Multicasting - How to send a hint to the router?

I found a multicasting example at http://ntrg.cs.tcd.ie/undergrad/4ba2/multicast/antony/example.html. After correcting some errors, this program seems to work fine within our network. I now need to ...
2
votes
3answers
2k views

Why is a hash used instead of a simple compare for filtering multicast frames?

From the book Unix Network Programming, The frame is received by the datalink on the right based on what we call imperfect filtering, which is done by the interface using the Ethernet ...
1
vote
3answers
49 views

Does enabling dhcp stops broadcasting within the network (currently on static)?

I have recently found the broadcasting in a network which is running on static IP's. If I enable DHCP will the broadcasting stops? Which is the best way to prevent broadcasting?
2
votes
2answers
156 views

Broadcasts in IPv6

I'm aware of the fact that broadcast has been removed from IPv6 and just has multicast instead. However, recently I read "This process (ARP) is now achieved via a multicast address called the ...
1
vote
2answers
1k views

Does a multicast source have to be connected to the RP for Cisco PIM-SM to work?

I'm fairly new to networking in general, but I need to develop a 4 point mesh with redundant paths routing multicast from point A to points B and C. I've already setup the mesh and have network ...
1
vote
2answers
811 views

IGMP Query Interval

What adverse effects could occurred if I set the igmp snooping querier query-interval to 1 second in the switch? The default in switch is 60 seconds
1
vote
1answer
433 views

Static Multicast MAC address term

Is the Static Multicast MAC address term the same as hardware ethernet MAC address (wan0)? In devices where two MAC addresses is present, i.e. lan0, wan0.
3
votes
1answer
1k views

multicast not working in two segment network

I have two network segments connected to a single Cisco router by Cisco switches. I've enabled multicast routing on the router by running following commands: ip multicast-routing in configuration ...
1
vote
0answers
147 views

Which one is the best method when it comes to multicast (stub)?

I want to set my device to L3 mode (specifically, 3560X-S). In particular, I want yo configure multicast. Because I haven't been configuring as multicast, I'm here to ask you about multicast ...
7
votes
2answers
132 views

VLAN clarification

I've inherited a network with approximately 200 computers and no VLANs configured. We are currently adding a system that uses multicasting to communicate with each other and will be adding VoIP in 2 ...
2
votes
1answer
330 views

Why is only 24 bits of the MAC address used for multicasting?

When doing neighbor discovery in IPv6, the last 24 bits of the hosts MAC address is glued on to some link local multicast prefix. I'm wondering why 24 bits? Why not 48, or 32, or 16? What happens if ...
3
votes
3answers
12k 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 ...
1
vote
0answers
1k views

Cisco SG300 switch identifies itself as duplicate IP address

We've enabled IGMP snooping on one of our VLANs. The configuration used is: bridge multicast filtering ip igmp snooping ip igmp snooping vlan 1 ip igmp snooping vlan 1 querier We're now seeing the ...
3
votes
1answer
5k views

Point-to-point vs unicast, and multiaccess vs multicast/broadcast?

From Tanenbaum's Computer Networks: Point-to-point links connect individual pairs of machines. To go from the source to the destination on a network made up of point-to-point links, short ...
1
vote
2answers
463 views

Routing eigrp between socniwall

Hello and good afternoon well i we have to router sending hello to the multicast 224.0.0.10 cisco 800 series in both sides, can i form an adjacency between them even if a sonicwall is between the, ...
1
vote
3answers
422 views

Filter multicast traffic to WiFi SSID

I have a set of broadcasting devices that are using multicast. Here is the configuration : L3 SWITCH# igmp-snooping interface Vlan-interface280 description BroadcastDevice ip address x.x.x.x 255....
2
votes
2answers
891 views

Multicasting questions

Ok, Basic question is this. show ip igmp snooping groups Is not returning the multicast groups I am creating More in-depth explanation. I want to test multicast. I am on a flat network, and I ...
1
vote
1answer
59 views

Design thinking of Solicitation node address in IPv6

Recently I study RFC 4291, and the solicitation node address is defined in that spec. I know what and the function of this solicitation node address. But just wondering why does the address design as ...
8
votes
1answer
6k views

What is the correct mask to use with 224.0.0.0?

What is the best mask to use to allow computers to use the multicast IP address 224.0.0.0? I've only seen IP addresses using the lower 8 bits, in my case I just see 22 and 251. So my firewall uses ...
1
vote
1answer
5k views

Cisco: broadcast and multicast storm control on distribution switches

I just got some already configured switches that are giving a lot of problems on the network with port shutdowns due to storm control policies. Finally after dumping the running-config. I've saw ...
2
votes
2answers
3k views

TCPDUMP Output analysis

I'm running the following command on my backbone to monitor multicast traffic. I'm new to tcpdump usage and looking for some help: sudo tcpdump -i eth1 -n -p multicast I see a output like this - ...
3
votes
2answers
1k views

If I UDP multicast to 10 listeners in a multicast group, will my upload bandwidth usage increase by 10 fold?

My internet has an upload limit of 1 Mb/s. If I am in a UDP multicast group with 10 people and I send something to the group at a rate of .1 Mb/s, will my upload rate be 0.1 Mb/s or 1.0 Mb/s? Assume ...
16
votes
1answer
66k views

What are the benefits and cons of IGMP snooping?

Our new router is asking if we want IGMP snooping enabled. Not being familiar with this, I looked to the internet and got the following wiki description: IGMP snooping is the process of listening ...
5
votes
1answer
414 views

What is the difference between Unicast RPF and Reverse Path Forwarding?

What is the difference between Unicast RPF and Reverse Path Forwarding? They both verify the source address of each packet before forwarding it to the destination. Is Reverse Path Forwarding used ...
2
votes
2answers
91 views

When do UDP multicast streams/frames diffuse?

Please consider my network topology: (Machine A0) --- [Switch A] ============ [Switch B] --- (Machine B0) | ...
0
votes
1answer
176 views

ACLs - what does the number of matches mean?

First post here. In brief I have VLAN 1102 which is used as a multicast source VLAN. This has an IP multicast boundary to only allow out multicasts to receivers in VLAN 1101. The reason for doing ...
0
votes
1answer
236 views

What factors affect propagation time for wired / wifi multicast messages? [closed]

I have a newbie question on multicast delivery times. In this article on clock synchronisation they claim that the propagation time on a local network is close to zero. What is the propagation time ...
3
votes
1answer
1k views

What is the advantage of multicasting in IPv6 (compared to broadcast)?

I've been trying to familiarize myself with IPv6 and one thing that's left me hanging is the benefit of multicasting over broadcasting in IPv6. To use Neighbor Discovery Address Resolution as an ...
6
votes
2answers
1k views

IGMP Multicast router overrun

THE SYSTEM: I have a L2 Managed 1Gbps switch with IGMP snooping (the switch I'm testing with is a TP-Link TL-SG3216). I have several identical devices (these are embedded devices that we are ...
2
votes
1answer
81 views

Valid broadcast and multicast addressing

The other day I ran across a piece of software configured to "multicast" using the address 255.5.6.7. While I've seen local broadcast (255.255.255.255) and "true" multicast (as defined in rfc5771), ...
4
votes
4answers
11k views

Is multicast possible in tcp?

I got an assignment to implement unicast, multicast and broadcast in UDP or TCP in java, so I searched for it and I only got UDP implementation of multicast. My question is following: Is there ...
3
votes
1answer
2k views

overcome microbursts in cisco router or transmitting linux machine

I have linux machine multicasting UDP streams with Java applications. The multicats go though ciso router. I see lot of packet losses at receivers. Checking ports in routers reveals overruns counter ...
3
votes
1answer
442 views

Multicast over Unicast IPv4 Routing

I have a little question and I did not find any direct answer on the WWW. So maybe someone else in this forum has the answer. I have two Cisco 2960X switches running in a stack with the sdm prefer ...
1
vote
2answers
600 views

Unidirectional untagged VLAN into another untagged VLAN

I was asked to review a network architecture at work. As I am not very familiar with VLAN utilization with multicast, that is why I am here to request your help. The old network consists of many ...