Internet Group Management Protocol(IGMP) is used by hosts to for request multicast data for a particular multicast group. This communication takes place between the (igmp enabled)routers present in the subnet and the hosts. Hosts can subscribe to a multicast group or leave it using IGMP.

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Does this mean the DoD is listening to my D-Link Router? [migrated]

I've only recently been monitoring my router activity and this Incoming listing from a DoD IP address is almost always present. It looks as if they are using the IGMP Protocol to sniff at my domain, ...
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16 views

IGMP Router Mode VS Proxy Mode

I am trying to understand the difference between IGMP Router Mode and IGMP Proxy Mode here, http://technet.microsoft.com/en-us/library/cc957920.aspx There is a question for an exam I am studying that ...
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11 views

IGMP Snooping limitations and when do you start to use PIM?

At a head end I've just inherited, all our multicast streams run on cisco switches with IGMP snooping enabled. Because all these streams are to be kept local and isolated we've never really looked ...
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1answer
58 views

Does the IP -> Ethernet multicast address mapping ambiguity matter for IGMP snooping switches?

There are 2^28 possible IP multicast addresses, but only 2^23 possible Ethernet (MAC) multicast addresses (http://technet.microsoft.com/en-us/library/cc957928.aspx), which is why e.g. 224.1.1.1 gets ...
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2answers
147 views

Possible to emulate an IGMP querier in software?

I have a L3 switch that does IGMP snooping, but it cannot act as an IGMP querier, and there is no IGMP querier connected to this network. Would it be possible to implement an IGMP querier in ...
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49 views

PIMD daemon needs long time to send PIM join message

I am using the PIMD daemon on Ubuntu Server 12.0.4 (32-bit). When it receives IGMPv2 membership report for certain group, it takes sometimes two, sometimes five seconds to send PIM join message to its ...
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1answer
69 views

Window 7 source-specific multicast (SSM)

We are planning to stream video feeds over multicast to managed Windows 7 devices. Does Window 7 support source-specific multicast at the OS layer (as the receiver)? It appears that XP and Vista both ...
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1answer
293 views

Should IGMP Snooping be configured on all Layer 2 switches on LAN?

We've used Multicasting for the first time in one of our applications and whilst I have got it working, I'd really like to fully understand how it works and what's going on behind the scenes. In an ...
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1answer
372 views

Is IGMP multicast traffic to a Xen VM host legitimate?

I run two Xen/CentOS 6.5 based VMs, both hosted by the same company, but connected to different networks (basic /24s w/ a single gateway at .1) in different physical locations. I developed an iptables ...
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67 views

IGMP 2.0 snooping switch timeout

Suppose a host computer has joined a multicast group 239.0.0.50 via IGMP 2.0. As per the IGMP 2.0 spec, when the host computer receives either a general query on 224.0.0.1 or a group wide query on ...
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1answer
427 views

How to allow IGMP traffic on Cisco switches?

I have a network formed by some Cisco switches (a 2960 at the center, some 2950s for distribution). The network uses VLANs, and there are trunks between the various switches. Computers in the same ...
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520 views

How to enable multicast routing in TMG 2010?

I have a TMG 2010 firewall between some office networks, which handles routing and firewalling; I need to let some application-specific multicast traffic flow between these networks; this is UDP ...
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1answer
165 views

Does the IGMP querier have to be connected to the multicast source?

I've been reading Allied Telesis' guide on configuring IGMP, which has been quite enlightening so far. However, I'm still wondering whether the IGMP querier has to be connected directly to the ...
2
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0answers
178 views

network leave/unscribe multicast group

I have debian based server where I need to subscribe a multicast. After doing it with headless mpalyer I can see the following: root@ca1:~# netstat -g IPv6/IPv4 Group Memberships Interface ...
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1answer
2k views

In ubuntu, which process is sending igmp packets?

My Ubuntu keeps sending out IGMP Query requests for following IPs: 239.255.255.255.253, 224.1.1.7 and 234.55.66.77. I figured this out from Wireshark. As per IGMP spec, I believe query requests are ...
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2answers
354 views

Can l2tp carry IGMP packet?

If a client connects to one vpn server, can it join a video meeting which is based on IGMP?
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1answer
829 views

IGMP V3 support in Linux-2.6.35

I am trying to start a bridge connection and force it to use IGMPV3. The following command will explain my issue better : The below is the output of force_igmp_version before issuing brctl commands ...
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1answer
372 views

Catalyst 3560G SPAN session not mirroring IGMP packets

I am developing a device which acts as a multicast host, and want to observe it as it responds to IGMP Queries. My Catalyst 3560G is set up as follows (full config below): Port 0/1 is a TFTP server ...
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4answers
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Capturing multicast data with Wireshark with IGMP Snooping Enabled at the switch

I am trying to capture multicast traffic via Wireshark (actually TShark), however the switch has IGMP snooping enabled and will only send Multicast traffic on the ports that have an active IGMP ...
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2answers
2k views

IGMP Membership under Linux (igmp_max_memberships)

I'm experiencing issues related to OSPF (which relies on Multicast) not allowing us to work with enough adjacencies and was told to look at: /proc/sys/net/ipv4/igmp_max_memberships Now, while it's ...
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1answer
1k views

Cisco 3560+ipservices — IGMP snooping issue with TTL=1

I've got a C3560 with Enhanced (IPSERVICES) image, routing multicast between its VLANs with no external multicast router. It's serving a test environment where developers may generate multicast ...
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1answer
1k views

openSUSE 11.3 multicast IGMP v2 works on one vlan, but not the other vlan

I have a server running openSUSE 11.3, with vlan5 and vlan40 configured on eth7. I want to join two multicast IGMP v2 groups, one on vlan5 and one on vlan40. When I send out the IGMP v2 Membership ...
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2answers
2k views

IGMP/Multicast routing in Linux

I need to route IGMP/Multicast traffic across two networks. I have a Linux box with two NICs, one public, one private. Need devices on the private network to flow to public. I'm pretty certain I ...
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3answers
531 views

Cisco multicast configuration

I'm on an isolated (for now) catalyst 3560e. I have a multicast source, which when enabled, causes flooding to all switch interfaces. I have a second different multicast source, which does not cause ...