Questions tagged [multicast]
For questions about multicast communications and protocols.
185
questions
2
votes
2answers
93 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
54 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" link-...
1
vote
0answers
11 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
53 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
75 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 ...
1
vote
1answer
42 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
79 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 ...
1
vote
4answers
86 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
171 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
47 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
117 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
198 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
88 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
131 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
56 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
36 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
281 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
98 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
69 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
511 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
54 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
160 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
332 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?
8
votes
1answer
431 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
2k 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
46 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
103 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
262 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
1k 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-...
4
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
593 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
2k 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
189 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
246 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
309 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) ...
2
votes
2answers
5k views
Multicast between VLANs
I've following scenario
Upper computer on VLAN 10 is sending some multicast messages and lower computer on VLAN 10 sends IGMP join periodically.
Lets say MC address is 224.1.1.1
Now, computer on ...
2
votes
3answers
721 views
Translate between multicast addresses
I have an application with a bug that does not recognize a certain multicast address as valid. It's an address used by another system i don't have control over, and these two systems communicate via ...
1
vote
2answers
987 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 ...
2
votes
1answer
49 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 ...
22
votes
2answers
10k views
Is multicast on the public internet possible? And if yes: How?
Is it possible to use multicast on the public internet? If yes: How? Are special IP addresses required and where do you get them from?
1
vote
1answer
128 views
Multicast summarization
I was wondering, does it make any sense to summarize(supernet) multicast IPv4 addresses ? Can anyone please explain why yes, or no ?
1
vote
1answer
168 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 ...
2
votes
1answer
461 views
Rationale for EXCLUDE mode in mutlicast IGMPv3 / MLDv2
Both IGMPv3 and MLDv2 have an include and an exclude mode, where a multicast listener can specify to either listen only for packets from some list of source addresses (include) or only for packets ...
2
votes
1answer
999 views
IGMP snooping across VLANs
Set up:
Core switch: C1
C1 is an L3 switch--there is no router
Access switches: A1, A2, A3
VLANs: V1, V2
Hosts: H11, H12, H13, H21, H22, etc.
Connections:
C1 connects to A1, A2, A3
A1, A2, A3 each ...
0
votes
1answer
47 views
What are “Unicast identity tokens”?
I was reading an introduction to IPv6 which talks about the depletion of IPv4 addresses.
I came across the following line:
As noted in RFC 5735 a number of address blocks are reserved for
users ...
1
vote
1answer
151 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 ...
1
vote
1answer
365 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 ...
2
votes
1answer
5k views
Which VPN Types/Protocols inherently support Multicast Traffic?
At my work, we build mobile networks from scratch for customers regularly. (Mobile Networks: think battery powered LTE router with wifi.) Since we build from scratch we can be vendor agnostic and ...
