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How to Configure Cisco SG300/SG500 forNetworked AVThe following is a step-by-step guide to configuring a Cisco SG300 or SG500 network switch for use with SVSI Networked AV Products.

Configuring IGMP Snooping

IGMP Snooping must be enabled on the switch to manage the flow of registered multicast traffic. Once IGMP Snooping is enabledmulticast groups will be registered on the switch when receivers request to join multicast groups. Multicast traffic destined for registeredmulticast groups will then be forwarded only to interfaces on which group-member receivers are attached.

1) Under enable the setting (disabled by default) and click :Multicast > Properties Bridge Multicast Filtering Status Apply

Whenever changes are made to Cisco SG the running configuration must be copied and saved as the startup configuration orthe changes will not persist if the switch is rebooted.

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2) Under enable the setting (disabled by default) andMulticast > IPv4 Multicast Configuration > IGMP Snooping IGMP Snooping Statusclick :Apply

3) Under select the VLAN you want to enable IGMP Snooping on and click Multicast > IPv4 Multicast Configuration > IGMP Snooping Edi:t

4) In the Edit IGMP Snooping Settings popup window (popups need to be enabled in the browser) enable the seIGMP Snooping Statustting and click :Apply

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5) Confirm that the shown for the VLAN under IGMP Snooping Operation Status Multicast > IPv4 Multicast Configuration > IGMP now says :Snooping “Enabled”

6) Under Multicast > Unregistered Multicast configure all interfaces for (set to Forwarding by default) and click . ThisFiltering Applyprevents unregistered multicast (i.e., streams from encoded that are not being requested by any decoders) from flooding to anyinterfaces.

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Configuring IGMP Querier

Each VLAN that manages multicast traffic with IGMP Snooping requires an IGMP Querier. The IGMP Querier periodically queries theVLAN to confirm that receivers want to maintain memberships with multicast groups. If multiple Queriers are enabled on the same VLANan automatic election process will occur - the Querier with the lowest IP will win and all other Queriers will stop sending queries. Theposition of the Querier in a multi-switch environment should be carefully considered, especially for a high-bandwidth multicast applicationsuch as Networked AV, as all multicast traffic always flows towards the Querier. Without a Querier the multicast group memberships onIGMP Snooping switches will timeout after a set period of time (typically 260 seconds) requiring the receivers to then rejoin the multicastgroup in order to start receiving multicast traffic again.

1) Under confirm that the setting is enabled (enabled byMulticast > IPv4 Multicast Configuration > IGMP Snooping IGMP Querier Statusdefault). If it is disabled, enable it:

2) Under Multicast > IPv4 Multicast Configuration > IGMP Snooping select the VLAN you want to enable IGMP Querier on and click :Edit

3) In the Edit IGMP Snooping Settings popup window enable the setting (disabled by default), confirm that the IGMP Querier Status IGM setting is configured for (v2 is default), and click .P Querier Version v2 Apply

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4) Under Multicast > IPv4 Multicast Configuration > IGMP Snooping confirm that setting for the VLAN now saysIGMP Querier Status“Enabled”. Under the field should be the switch’s own IP address:Querier IP Address

Configuring Non-Querier in Multi-Switch Environment

Any Cisco SG switches in a multi-switch IGMP Snooping environment that are not intended to be the Querier should still be configured toenable IGMP Snooping. In addition it is important that the non-Querier switch knows which interface connects to the Querier so multicasttraffic can be forwarded appropriately - all multicast traffic needs to flow towards the Querier via the Multicast Router (mrouter) Port. TheMulticast Router Port can be dynamically learned (by listening for Queries) or statically assigned. By default, Cisco SG will forwardunregistered multicast traffic to all interfaces and the filtering/forwarding of unregistered multicast traffic is a per-interface setting. If theunregistered multicast filtering setting is applied to an interface which is also the Multicast Router Port the Cisco SG will not forwardunregistered traffic to the mrouter port. This behaviour of not forwarding all multicast traffic to the Querier is at odds with the requirementsdefined in the IGMP standard in that all multicast traffic should always flow towards the Querier so can cause issues if sharing multicasttraffic between sources and receivers connected to different switches in a multi-switch environment.

1) Under Multicast > IPv4 Multicast Configuration > IGMP Snooping disable the setting (enabled by default) andIGMP Querier Statusclick . Disabling this global setting overrides the settings of the individual VLAN’s:Apply IGMP Querier Status

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2) Under Multicast > Multicast Port confirm that the switch has discovered the Querier on one of the interfaces, listed as . NoteDynamicthat it may take some time for this multicast router port to be discovered:

The Multicast Router Port can be statically configured by selecting “Static” however this configuration should only be requiredrecommended if switches from different vendors are used in the same network environment and they are not able to auto-discover theIGMP Querier.

If the Multicast Router Port is not able to be dynamically discovered this could indicate that there is no IGMP Querier configured on thenetwork. In a single-switch environment the IGMP Querier feature must be enabled in order to prevent group-membership timeouts but ina multi-switch environment an IGMP Querier is also required in order for multicast traffic to flow from one IGMP Snooping enabled switchto another.

3) Now that the Multicast Router Port has been configured (either dynamically discovered or statically assigned) under Multicast >Unregistered Multicast configure the same interface to . All interfaces that are not Multicast Router Ports should be set to FiltForwarding ering:

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This is done because the setting on the Cisco SG300/SG500 switches overrides the default behaviour of howUnregistered Multicastswitches are supposed to handle the flow of multicast traffic to Multicast Router Ports in that all multicast traffic should always beforwarded to the Multicast Router Port (i.e., towards the Querier).

Configuring Immediate Leave

When a receiver leaves a multicast group the traffic flowing to the interface destined for that group does not stop straight away. IGMPallows time for the Querier to confirm that other receivers, possibly attached to the same interface and joined to the same multicast group,do not want to maintain a connection to the group once a receiver leaves the group before the forwarding of traffic for that group on thatinterface ceases. For high-bandwidth multicast applications, such as Networked AV where the stream size can easily exceed half theavailable bandwidth, the Immediate Leave feature should be enabled to prevent data saturation on interfaces where a receiver leavesone group and then immediately joins another group.

1) Under Multicast > IPv4 Multicast Configuration > IGMP Snooping select the VLAN you want to enable IGMP Snooping on and click Edi:t

2) In the Edit IGMP Snooping Settings popup window enable the setting and click :Immediate Leave Apply

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