Questions tagged [multicast]
For questions about multicast communications and protocols.
218
questions
0
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0answers
12 views
How do multicast addresses reduce the traffic sent in the network? [duplicate]
I read this on a website: "By using multicast mechanism, you save an enormous amount of network resources and additionally improve the multicast content transmission"
But also, each ...
3
votes
1answer
78 views
IPv6 neighbour discovery blocked by MLD snooping switch
I recently noticed that my IPv6 multicast traffic was being broadcasted to all hosts connected to a switch, even those that had not subscribed to the traffic.
To fix this, I enabled MLD snooping on ...
2
votes
1answer
287 views
If a switch doesn't support multicast, are multicast packets simply flooded out all ports?
If a switch doesn't support multicast, are multicast packets simply flooded out all ports? This would allow multicast enabled hosts to at least still receive the multicast frames.
Follow up question. ...
1
vote
1answer
21 views
broadcast instead of multicast for CARP/VRRP/keepalive
In many cloud environments, multicast is blocked therefore when trying to configure CARP/VRRP customer needs to add a dedicated switch.
For example, CARP partially works if using a vSwitch from Hetzer,...
0
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0answers
30 views
Disable automatic multicast route creation on Arista switch (only static)
With the following command we can disable PIM on interface level:
interface Ethernet53/1
no pim ipv4 sparse-mode
Is there also a command to disable PIM on the whole switch? This way we would like to ...
2
votes
3answers
230 views
Why does OSPF use flooding despite using multicast?
We know that flooding is only possible in layer2 switch. But in OSPF router in layer3 uses flooding with multicasting. Suppose we have one router in OSPF uses multicast address 225.0.0.9. If router ...
0
votes
2answers
143 views
Class D network for multicasting between group
We know Multicasting is defined as a single source sending to multiple recipients on a network when the receiver broadcasts a signal for acceptance. Multicasting has its own Class D IP addressing ...
1
vote
1answer
83 views
IGMP in multiple switches with multiple Senders and Receivers in same VLAN
I am trying to send multicast traffic from 3 Senders to corresponding Receivers in same VLAN (100) spread across 3 switches.
I setup a Querier in one of the switch, but it doesn't seem to forward ...
2
votes
0answers
28 views
No entry in the multicast RIB while PIM join is present
I have a router which receives multicast traffic from the source over a multicast LSP(signaled by LDP):
root@PE3> show pim join detail
Instance: PIM.master Family: INET
R = ...
0
votes
1answer
38 views
Juniper vMX router silently drops SSM traffic
I have a Juniper vMX router with two interfaces: ge-0/0/0.0 facing the multicast sender and ge-0/0/2.0 facing the multicast receiver. The router receives multicast packets addressed to 232.1.1.1 on ...
2
votes
2answers
73 views
Query regarding IGMP Querier Election Process
I wanted to understand how a querier election takes place.
Say we have to L3 devices with ip address 10.1.1.2 and 10.1.1.1.
PIM is not enabled anywhere.
I checked around and found that the flow would ...
1
vote
1answer
44 views
How Pruning avoids loops in Protocol Independent Mulitcast (PIM- SM)?
I can not think of a scenario, how pruning avoid loops in PIM-SM when a router joins a SPT. I understood that it avoids duplicate messages, but how it avoids loops?
I want a scenario where the router ...
0
votes
1answer
219 views
Forward Avahi mDNS packets from one network to another [closed]
I have a Linux device connected to two different networks. eth0 is connected to 198.18.248.x and wlan0 is connected to 198.19.255.x. Another device connected to the 198.18.248.x network and it's ...
0
votes
2answers
52 views
PIM Packet and NAT
Is it possible to NAT PIM Join packet?
Assume the receiver and the source are in two different private network. Thus NAT is required. The upstream source and the groupe are included in the PIM Join ...
0
votes
1answer
66 views
What are the benefits of using MP-BGP multicast address family, under the context of inter PIM domains multicasting?
Under the context of inter PIM domains multicasting, 1 RP on each PIM domain (2 domains), attached with eBGP, with MSDP peering to exchange the actives sources, what are the benefits of using the MB-...
0
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0answers
51 views
Does ARISTA's EOS support SSM mapping like CISCO?
On Arista L3 switch, I have to combine usage of PIM-SM for IGMPv2 and SSM for IGMPv3 devices.
On CISCO switch, there is an option like
ip igmp ssm-map
Which allows you, for example, static mapping of ...
0
votes
0answers
26 views
static IP multicast routing with IPSEC
for a specific application, I need to route a multicast flow with IPSEC (we use a CISCO ASA 5508 firewall), I am not a network expert then I will try to explain as best as I can our issue
I don't need ...
0
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0answers
36 views
Does multicast over tunnels (e.g., GRE) require IGMP/MLD?
When subscribing to a multicast group on a tunnel device such as a GRE tunnel, are you supposed to participate in IGMP/MLD over that tunnel in order to announce your membership in the multicast group? ...
0
votes
1answer
219 views
How to Stream from VLC using Multicast? [closed]
I have the following topology:
With the following router configurations:
R1:
hostname R1
!
boot-start-marker
boot-end-marker
!
!
!
no aaa new-model
no ip icmp rate-limit unreachable
!
!
!
!
!
!
no ip ...
1
vote
0answers
111 views
Multicast traffic through Cisco3850
I have a test scenario and trying to pass multicast traffic through Cisco 3850 according to the following diagram:
0
votes
1answer
64 views
What prevents a device from receiving its own multicast stream, and can it be turned off?
I know that it is normally not possible for a device to receive its own multicast stream on the same network interface where it transmitted said stream. I also understand why this is sensible, and ...
2
votes
1answer
81 views
In an IGMP V2 membership report message, isn't the destination Ethernet address based on the multicast group IP address?
Specifically, I think for this message type the Ethernet destination address always starts with 01:00:5E, followed by the second byte of the IP address masked with 0x7F, followed by the third and ...
0
votes
1answer
39 views
Are there broadcast/collision domains on non-Ethernet networks?
What if we have routers or hosts connected via ATM, Frame Relay, or SONET; that is, what if we have IP over SONET, IP over ATM, IP over Frame Relay, etc., do we still have broadcast domains and ...
2
votes
2answers
993 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 ...
12
votes
3answers
4k views
Why isn't multicasting more popular?
Multicasting seems provide an efficient method of routing networking traffic from a source to multiple end users, especially at this moment in time with teleconferencing, streaming media, online ...
1
vote
2answers
162 views
Why does IPv6 NS not use unicast address but multicast
This is a follow up of Why not put unicast address in IPv6 packet containing NDP neighbor solicitation instead of solicited-node multicast address?
The accepted answer makes no sense.
It states the ...
2
votes
0answers
230 views
IGMP Snooping issue. probably
I have multicast hosts that keep leaving a group, only to join back up which results in loss of video feeds.
The network consists of a variety of Cisco 2960's and a Cisco 9300 w/ PIM Sparse mode set ...
0
votes
0answers
40 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 ...
1
vote
0answers
110 views
How should OSPF work over WiFi? [closed]
I've had problems running OSPF over my WiFi network, and it seems to be related to multicast. The routers can't maintain a neighbor relationship, and when I watch the packet traffic I see one router ...
0
votes
1answer
68 views
In PIM Sparse Mode, can the Rendezvous Point be the first or last hop router?
In tutorials and configuration examples, usually, the Rendezvous Point is described as the central registry to match multicast senders with receivers. FHRs and LHRs send PIM messages to the RP to be ...
0
votes
2answers
63 views
What's so special about the multicast address range?
I'm reading a little on IP multicast and have trouble understanding the significance of multicast address range (224.0.0.0 - 239.255.255.255). What makes this range significant? Why not multicast on ...
0
votes
1answer
410 views
How to enable Inter-VLAN multicast traffic on a layer 3 Siemens RX1510 Network Switch using IGMP?
I have a single Layer 3 Siemens RX1510 network switch split into 4 separate VLANs on different subsets.
Name | Gateway | Subnet
VLAN1 | 198.97.100.123 | 255.255.255.0
VLAN2 |...
4
votes
4answers
724 views
Layering unicast addressing over multicasts
My question has to do with layering of unicast over multicast and has two parts.
Part 1. IP unicast over MAC multicast
First part of the question is whether there is a standard that prohibits use of ...
2
votes
2answers
992 views
How do hosts subscribe to multicast addresses?
So I am having a hard time finding materials online that explains how multicast address are set.
I understand what unicast is: Basically one to one communication. In this scenario, an address ...
2
votes
1answer
83 views
How can MLDv2 work according to the RFCs 3810 and 4606?
When IPv6 Stateless Address Autoconfiguration is happening, an interface/node has to join the all-nodes multicast address and the solicited-node multicast address AFTER forming a "tentative" ...
1
vote
0answers
40 views
Linux local multicast egress follows FORWARD chain when smcroute is active [closed]
Rather than a configuration issue, this is a "Is this expected behaviour" question. Given the following test box (Stock Ubuntu 18.04 LTS):
+---------------------------------------+
| ...
2
votes
1answer
95 views
Interaction between multicast sources and first-hop routers (possibily DRs)
I might be missing the obvious but I would like to know how the first-hop routers are aware that multicast sources are sending multicast packets and such packets are eligible for the PIM-register ...
0
votes
2answers
404 views
Unicast to Multicast possible?
could I check if it is possible to convert TCP traffic to UDP multicast and if there are any appliances / switches that can do so?
E.g. Workstations A, B and C establishes a TCP connection with ...
2
votes
2answers
312 views
How to handle multicast address collisions?
Assume 2 multicast IP addresses IP1 and IP2 whose mac addresses are same due to collision
Let's say a host's NIC has joined multicast stream IP1 and another host on the original host's subnet joined ...
5
votes
1answer
333 views
IP pim sparse or dense mode
I have an IF/RF station that is receiving RF signals from satellites, then converted to IP to be encoded, decoded, multiplexed, and modulated again to RF so that it's sent to wireless and wired ...
2
votes
4answers
218 views
Why not put unicast address in IPv6 packet containing NDP neighbor solicitation instead of solicited-node multicast address?
This is a follow-up question to Why is the NDP Neighbor Solicitation message sent to the solicited-node address?.
Summary: say I would send an IPv6 packet and put the unicast address of the host I ...
2
votes
3answers
493 views
Will pinging the multicast "all hosts" IP 224.0.0.1 fill my ARP cache with all hosts on my current subnet?
Just wondering in case I ever have a want / need to see all the hosts on my subnet.
4
votes
1answer
95 views
Function of the P-bit flag in an IPv6 multicast
Currently I'm trying to learn (common) things about IPv6 and started with the address format and the address scopes. Finally I reached the multicast part where my problem with the definiton of the ...
1
vote
1answer
450 views
Can communication to broadcast 224.0.0.1 be made to reach hosts outside of the local subnet?
I been asked the question if it is possible for an a IP host to use multicast to address 224.0.0.1 in order to reach (and get a response from) another host which is not on the local network segment ...
0
votes
1answer
928 views
Routing Multicast on a single L3 switch
I am currently testing how to route Multicast on a single L3 switch. I am currently testing 2 Vlans. I researched and I know I have to use PIM or Mrouter port for this scenario but that is for when ...
0
votes
1answer
236 views
Avoid bottleneck in UDP multicast
The question is that a server is serving a multicast group with UDP. Lets say that its a file server and it will be serving big files (~10GB). Now we have a multicast group with multiple clients. Some ...
0
votes
1answer
270 views
Multicast in one VLAN
I need to receive multicast traffic over L2 segment on my client machine. But for some reason I am unable to do it.
To my understanding with such scheme I should receive traffic if inbetween Juniper ...
0
votes
1answer
115 views
Multicast in enterprise network
Once I have heard from a professional that multicast is forbidden (or not suggested or not allowed) in enterprise networks from 2014. (He referenced to a standard or recommendation document or ...
0
votes
1answer
86 views
Purpose of prune message in rpf
I read that when a multicast aware router without receivers received a multicast message, the router will send an upstream prune message. I don't understand what is the purpose of the prune message. I ...
2
votes
1answer
952 views
Setting Destination MAC address for RTP/UDP packets
I have a requirement where I have to send the UDP packet to a destination multicast IPv6 address. In addition to that the packets must also have corresponding destination multicast MAC address set. I ...
