HP J9726A User Manual

IGMP proxy forwarding
When a network has a border router connecting a PIM-SM domain to a PIM-DM domain, the
routers that are completely within the PIM-DM domain have no way to discover multicast flows in
the PIM-SM domain. When an IGMP join occurs on a router entirely within the PIM-DM domain
for a flow that originates within the PIM-SM domain, it is never forwarded to the PIM-SM domain.
The IGMP proxy is a way to propagate IGMP joins across router boundaries. The proxy triggers
the boundary router connected to a PIM-SM domain to query for multicast flows and forward them
to the PIM-DM domain. IGMP needs to be configured on all VLAN interfaces on which the proxy
is to be forwarded or received, and PIM-DM must be running for the traffic to be forwarded.
You can configure an IGMP proxy on a selected VLAN that will forward IP joins (reports) and
IGMP leaves to the upstream border router between the two multicast domains. You must specify
the VLANs on which the proxy is enabled as well as the address of the border router to which the
joins are forwarded.
How IGMP proxy forwarding works
The following steps illustrate how to flood a flow from the PIM-SM domain into the PIM-DM domain
when an IGMP join for that flow occurs in the PIM-DM domain. See Figure 2.
1. Configure Routing Switch 1 with the IGMP proxy forwarding function to forward joins toward
Border Router 1; in addition, configure Routing Switch 1 to forward joins from VLAN 1 toward
Border Router 2, as is VLAN 4 on Routing Switch 3.
2. Configure VLAN 2 on Routing Switch 2 to forward joins toward Border Router 1.
3. When the host connected in VLAN 1 issues an IGMP join for multicast address 235.1.1.1,
the join is proxied by Routing Switch 1 onto VLAN 2 and onto VLAN 4. The routing information
table in Routing Switch 1 indicates that the packet to Border Router 1 and Border Router 2 is
on VLAN 2 and VLAN 4, respectively.
Figure 2 IGMP proxy example
4. Routing Switch 2 then proxies the IGMP join into VLAN 3, which is connected to Border Router
1.
IGMP proxy forwarding 19

HP J9726A Specifications

General

Product Number	J9726A
Device Type	Switch
Layer	Layer 3
Power Supply	Internal
Jumbo Frame Support	Yes
PoE	No
Ports	24 x 10/100/1000
Additional Ports	4 x SFP+
Management	CLI, SNMP
Form Factor	Rack-mountable
MAC Address Table Size	32000 entries

Summary

1 Multimedia Traffic Control with IP Multicast (IGMP)

IGMP general operation and features

Explains IGMP's role in reducing bandwidth usage for multimedia applications.

IGMP operating features

Details the operational aspects and enhancements of IGMP configuration.

Configuring and displaying IGMP (CLI)

Viewing IGMP configuration for VLANs

Shows how to view IGMP configuration details for specific or all VLANs.

Viewing the current IGMP configuration

Enabling or disabling IGMP on a VLAN

Configuring per-port IGMP traffic filters

Configuring the querier function

Configuring static multicast groups

Automatic fast-leave IGMP

Configuring fast-leave IGMP

Configuring forced fast-leave IGMP

IGMP proxy forwarding

How IGMP proxy forwarding works

Illustrates how IGMP joins are propagated across router boundaries for multicast flows.

Configuring IGMP proxy (CLI)

Adding or leaving a multicast domain

Manages multicast domain configurations, associating them with border routers and address ranges.

Using the switch as querier

2 Multimedia Traffic Control with IP Multicast (IGMP) v2 NG

IGMP Context Commands

Provides CLI commands for configuring IGMP.

VLAN Context Commands

Enabling or Disabling IGMP on a VLAN

Covers enabling or disabling IGMP on a specific VLAN.

Configuring the Querier Function

Manages the switch's ability to function as an IGMP querier.

Configuring Per-Port IGMP Traffic Filters

Defines how each port handles IGMP traffic (auto, blocked, forward).

Configuring Fast-Leave IGMP

Configuring Forced Fast-Leave IGMP

Configuring Static Multicast Groups

Show Commands

Viewing the current IGMP configuration and status

Displays IGMP status for all enabled VLANs or a specific VLAN.

Statistics and State commands

show ip igmp statistics

Displays high-level IGMP statistics for all VLANs on the switch.

show ip igmp vlan <vid> statistics

Displays IGMP statistics for a specific VLAN on the switch.

Help function commands

show ip igmp

Displays IGMP status, global configuration, or statistics.

3 IP Routing Features

IP interfaces

Details how IP addresses are associated with VLAN interfaces on routing switches.

IP tables and caches

Explains the IP routing table, ARP cache, and IP forwarding cache.

IP route table

IP global parameters for routing switches

ARP age timer

IP interface parameters for routing switches

Configuring IP parameters for routing switches

Configuring ARP parameters

Configuring forwarding parameters

Enabling forwarding of directed broadcasts

Configuring ICMP

Configuring static IP routes

Configuring a static IP route

Viewing static route information

Configuring the default route

Configuring ECMP routing for static IP routes

Configuring RIP

Configuring RIP parameters

Enabling RIP

Enabling RIP on the routing switch and entering the RIP router context

Enabling IP RIP on a VLAN

Configuring RIP redistribution

Defining RIP redistribution filters

Configuring for redistribution

Enabling RIP route redistribution

Viewing RIP information

Viewing RIP interface information

Viewing RIP peer information

Configuring IRDP

Enabling IRDP globally

Enabling IRDP on an individual VLAN interface

Configuring DHCP relay

Enabling DHCP relay

Configuring an IP helper address

Verifying the DHCP relay configuration

DHCP Option 82

Option 82 server support

General DHCP Option 82 requirements and operation

General DHCP-relay operation with Option 82

Option 82 field content

Forwarding policies

Configuration options for managing DHCP client request packets

Multiple Option 82 relay agents in a client request path

Validation of server response packets

Configuring Option 82

UDP broadcast forwarding

Configuring and enabling UDP broadcast forwarding

Globally enabling UDP broadcast forwarding

Configuring UDP broadcast forwarding on individual VLANs

Viewing the current IP forward-protocol configuration