Questions tagged [multicast]
For questions about multicast communications and protocols.
198
questions
2
votes
1answer
30 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
23 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 ...
0
votes
0answers
17 views
Multicasting with Layer 3 Switches [duplicate]
I was wondering if someone could advise on this please -
I want to set up multicasting on a network of layer 3 switches.
So I understand I should enable ip igmp snooping on all the switches and then I ...
1
vote
2answers
41 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 ...
0
votes
2answers
65 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
62 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
29 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
33 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
48 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
55 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
58 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
377 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
175 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
68 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
12 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
57 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
120 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
114 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
109 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
113 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
251 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
63 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
222 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
370 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
129 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
163 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
71 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
49 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
452 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 ...
1
vote
0answers
119 views
To multicast or not to multicast over LTE? [closed]
I have an IOT device with static IP connected to a Mikrotik LTE device on ether1. The IOT host sends a multicast packet every second. The packet contains the IP and MAC of the host.
IP-Multicast: ...
2
votes
1answer
110 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
647 views
Cisco 49XX multicast flooding
I have problem with multicast on cisco 4948.
I've got vlan 9 with muilticast, which configured on several ports. Switch floods multicast traffic on all ports configured with vlan 9. It consumes link ...
1
vote
1answer
58 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, ...
1
vote
1answer
178 views
Users on one VLAN cannot access multicast resources [closed]
Feel like I'm getting closer to fixing my issue...
This is the simplified version of the multicast...
-No RPF Failure
-pim sparse mode on all interfaces
-multicast routing enabled
I forced a group ...
2
votes
1answer
429 views
Is it possible to use 802.11n to send multicast?
I have tried to set the wifi multicast rates and find that all the multicast packets are send by 80211g, so that the max rate is 54M. Can I use the 80211n to achieve higher rate?
9
votes
2answers
517 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
3answers
3k views
OSPF and its use of Multicast
When it comes to OSPF and its use of multicast, am I correct in believing that IGMP forwarding and an IGMP querier is still required within the local segment?
My understanding would be without this, ...
1
vote
1answer
37 views
Is it possible that IPv6 multicast address is shown in the “IPv6 Address” column of the “show ipv6 neighbors” command in Junos?
Is it possible that IPv6 multicast address(i.e address from ff00::/8 address block) is shown in the "IPv6 Address" column of the "show ipv6 neighbors" command in Junos?
2
votes
2answers
54 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 ...
0
votes
1answer
118 views
Weird packet lost. Looking for some input
Like me start by saying I'm not an network expert but this situation got me scratching my head and you guys might be able to help.
The infrastructure is 4 switches (Dell 2848). 2 For the LAN and 2 ...
1
vote
1answer
292 views
Understanding IP multicast in linux [closed]
My ultimate goal is to setup IGMP snooping on a linux machine using netfilter hooks. This is for exploratory purposes to understand IGMP protocol.
The topology we are using is as follows:
| ...
3
votes
1answer
2k views
Using IGMP but Multicast still Flooding
Im new here.
I want to ask about the multicast,
The first case is, I have switch HP 2530 24 port with 24 10/100 and 2 100/1000 NIC, And i have servers with bandwidth video multicast around 120-...
5
votes
2answers
2k views
Why we use 224 as multicast address in many protocols?
I see in many protocols we use 224 multicast address as like eigrp uses 224.0.0.10 ospf uses 224.0.0.5 224.0.0.6
4
votes
3answers
674 views
Multicast routing on Huawei Quidway 5300 Switches
I have been testing a scenario which involves multicast routing for multicast traffic the scenario is pretty simple.
I have two L3 switches with OSPF running in between them, two computers are ...
3
votes
2answers
3k views
IGMP and multicast forwarding
So my question is, will using IGMP alone(without IGMP snooping, PIM...etc) making router forwarding multicast traffic?
I'm working on a buggy switch, but I don't know about networking too, so I'm ...
2
votes
2answers
204 views
Cisco: multicast unregistred forwarding on ME3400EG-2CS-A access switch
I am connected to the Internet through an Cisco ME3400EG-2CS-A access switch, routing enabled.
Gi0/1 and Gi0/2 are configured as a SVI (VLAN1) and on that ports I attached two pfSense firewalls with ...
3
votes
1answer
1k views
Network flooded with ICMPv6 Multicast Listener Report Packets
I recently noticed that 3 out of 4 Unifi APs kept reaching 100% CPU usage. When I jumped onto the networks and took a Wireshark capture I noticed 1000s of these packets being sent in just a matter of ...
2
votes
2answers
274 views
redundant vpn to remote location with redundant links
I have this situation:
Remote location with 6 devices collecting data and each connected to two VPN routers. Bonding is set up for those computers and data is sent to multicast address. Each VPN ...
3
votes
0answers
329 views
STB generate IGMP Leave without reason
In my network STB generates IGMP Leave (in STB logs "End of Stream") without any reason or there is something what I don't understand.
There is one exeption STB directly connected to PIM (ASR920) ...
