Questions tagged [multicast]

For questions about multicast communications and protocols.

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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 ...
2
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2answers
311 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 ...
2
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2answers
231 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 ...
2
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1answer
55 views

Should igmp table lookup misses flood to all ports?

With igmp snooping, upon receiving a multicast packet it looks up the table and decides which ports to forward the packet. What I'm wondering is, if there is not an entry in the table for that ...
2
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1answer
777 views

Unable to route multicast from IPcam (four vlans, one switch, one router with router-on-a-stick)

Okay, so I've been searching far and wide for a solution to my problem here. I want to be able to access an IPcam through its respective software across VLANs. Hardware: Cisco 1841 Router, firmware ...
2
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1answer
503 views

Understanding multicast destination mac addresses

I'm currently learning about how to convert between a multicast ip address and the destination mac address. I fully understand the terminology, how to do the conversion, and why the 23 bits, instead ...
2
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2answers
1k views

Is a VLAN relevant for multicast frames?

In a switched Ethernet network is there a use-case for having VLAN tags for frames that have a multicast MAC as destination address? I cannot find a use-case because: VLANs are generally used for ...
2
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1answer
145 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 ...
2
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2answers
950 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 ...
2
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2answers
92 views

When do UDP multicast streams/frames diffuse?

Please consider my network topology: (Machine A0) --- [Switch A] ============ [Switch B] --- (Machine B0) | ...
2
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1answer
89 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 ...
2
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1answer
523 views

Multicast update on wifi network

I hope my question is fine for this group, and if not, I'll remove it as soon as required. Hereis a shot description of our problem: Our system has many clients (about 500) that should be updated via ...
2
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1answer
948 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 ...
2
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1answer
790 views

Reserved multicast addresses

I can see MC address assignments HERE. However, I'm looking for what groups in the 225.0.0.x range represent. I know that the MACs for this range overlap the 224.0.0.x range in some (if not all) ...
2
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1answer
395 views

IP multicast support

I am currently learning about IP multicast. I am confused what support mechanism it needs for it to be used. For e.g support from OS , Network cards etc .. As per my understanding, IP multicast is ...
2
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1answer
137 views

PIM mode for low latency video [closed]

What is the best PIM mode for a campus video network? There are several relevant factors: All video is local to the campus. Click to view needs to be fast as possible (Life safety issues) Sources are ...
2
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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 = ...
2
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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 ...
2
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0answers
229 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 ...
2
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1answer
788 views

is it possible to register multicast IP addresses?

topic : IPv4 multicast addresses as per IANA docs Is it possible to register these addresses or they are reserved like 0.0.0.0/8, 10.0.0.0/8, 127.0.0.0/24, etc... ? When we read a specific multicast ...
2
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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-...
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0answers
275 views

Don't receive multicast traffic [closed]

I'm using multicast communications with IGMP snooping enable in the switch, I have 6 nodes (A, B, C, D, E, F), 3 sends data to different Multicast address and 3 receive data from every multicast ...
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1answer
444 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 ...
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3answers
445 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....
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2answers
3k views

Multicast ARP Switch

So a few questions that I've struggled to find firm answers on. 1: Does multicast use arp? So does it ask for a corresponding IP address? I think the answer is no, as it translates the IP to a MAC ...
1
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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,...
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1answer
76 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, ...
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3answers
173 views

How would I make a client find a server with an unknown IPv6 Address?

Let me first explain my situation: I am currently in the process of trying to build a solution for managing multiple Internet of Things devices on a network. It should be possible to automatically ...
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4answers
5k views

List over assigned global Ethernet MAC multicast address

Where are global Ethernet multicast MAC addresses assigned? Is this by Organizationally Unique Identifier (OUI), and if so, is there a homepage that shows all the assigned global Ethernet MAC ...
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2answers
160 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 ...
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1answer
184 views

Question Regarding IGMPv3 behaviour: Multicast Router appears to send Membership Report?

I'm new to how IGMP works. Recently, I was looking at a packet capture: I see that 172.18.1.3 sends a membership query to the all hosts address, leading me to assume that 172.18.1.3 is a multicast ...
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1answer
178 views

Multicast group membership

Context: Studying for CCNA I'm trying to understand multicast. I understand it conceptually, but I'm trying to understand implementation. For instance, in OSPF, how is multicast group membership ...
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3answers
675 views

Untagged customer traffic inconsistently sent over trunk

I have a catalyst 3750 which is giving me a headache. I have several "customers" who all produce an identical mixture of tagged and untagged traffic. I want to take this traffic in and then pass ...
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2answers
2k views

Does a network switch broadcast local IP Addresses?

Please consider the following scenario The router (Linksys E2000) has an INTERNET port where the main network is plugged in. The router has some ETHERNET/OUT ports where a switch, laptop or PC can ...
1
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1answer
114 views

Regarding PIM sparse mode

In PIM sparse mode, there is a Rendezvous Point.For any receiver, to join the (S,G) group,the last hop router waits until it receives the native multicast stream. Once it receives the native multicast ...
1
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1answer
531 views

IGMP and Multicast

I have 3 hosts (h1, h2, h3) on my LAN segment and a router with IGMP enabled. Now the host h3 wants to join the multicast group (239.0.0.2 say) Host h3 will send a membership report to 239.0.0.2 (...
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2answers
490 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
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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 ...
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2answers
208 views

Should the Multicast source in an ASM network be a member of the Multicast group?

What happens if traffic is sent to a multicast group from a host which is not a member of that multicast group ? Does the router keep any information for a valid Multicast source and discard this ...
1
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1answer
435 views

Multicast and HSRP

Does an HSRP VIP factor into the PIM designated router and IGMP querier election on a segment? Should they be located on the same interface or device? What would be the effects of having them separate?...
1
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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 ...
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1answer
864 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 ...
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1answer
333 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: | ...
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2answers
2k views

Command "ip nhrp map multicast dynamic" is not being saved into the configuration

For some reason, my Cisco router is not saving the command "ip nhrp map multicast dynamic". The command is recognized but not being saved to the configuration. I am not receiving any errors. Any ...
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1answer
508 views

multicast flow - send and received by same host

I have following issue: I have unit A which is connected to a non configurable switch which is totally flat and this switch is connected to a switch which has capabilities of layer 3 (BATM T5CL3 G ...
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1answer
665 views

Max hosts of subnet IPv6

When a interface takes an IPv6 address it does the DAD mechanism. A NS will be sent to the multicast address "solicited node multicast group address". If there is another interface in this multicast ...
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1answer
127 views

Multiple routed multicast groups on single switch

This is my lab environment: I have two rooms with one L2 access switch each with multiple vlans. The switches are connected to a L3 switch. All routing happens on this switch. I was able to configure ...
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2answers
720 views

NLB Multicast / Source Mac Address

So I've been trying to complete my MCSA, I'm now on 412. Anyway, NLB (network load balancing)... I'm struggling with how it works. Multicast: Each node in the cluster keeps it's own mac and IP ...
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1answer
1k views

Regarding Multicast over the internet

I was going through the use cases of GRE tunnel and see that it is also used to carry multicast traffic over the internet.I understand that multicast IP belongs to class D address which is a public IP ...
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1answer
67 views

Recieving a packet multiple times in a wireless LAN Network using multicast

I need to send a packet to more than one reciever (lets say 30). Assume I don't care that some of them do not receive it now (Application Layer will handle this). Now my solution is to use multicast, ...