/mcp2 00-10-2f-00-14-00 # 7/1 2 01-00-0c-cc-cc-cc # 1/9 2 01-00-0c-cc-cc-cd # 1/9 2 01-00-0c-dd-dd-dd # 1/9 2 01-80-c2-00-00-00 # 1/9 2 01-80-c2-00-00-01 # 1/9 3 01-00-0c-cc-cc-cc # 1/9 3 01-00-0c-cc-cc-cd # 1/9 3 01-00-0c-dd-dd-dd # 1/9 3 01-80-c2-00-00-00 # 1/9 3 01-80-c2-00-00-01 # 1/9 Total Matching CAM Entries Displayed = 19 The router sends a CGMP Join message to GDA 00-00-00-00-00-00 with the USA MAC of the router. Therefore, the router port is added to the router port list (see the first example below).On the router 6d01h: CGMP: Sending self Join on Fa0.3 6d01h: GDA 0000.0000.0000, USA 0060.70cd.83c9 On the switch MCAST-CGMP-JOIN: recvd CGMP JOIN msg on port 3/1 vlanNo 2 MCAST-CGMP-JOIN: join GDA 00-00-00-00-00-00 MCAST-CGMP-JOIN:USA 00-60-70-cd-83-c9 MCAST-ROUTER: Adding QUERIER port 3/1, vlanNo 2 MCAST-ROUTER: Creating RouterPortTimer for port 3/1, vlanNo 2 Switch_B (enable) show multi router CGMP enabled IGMP disabled Port Vlan
3/1 2-3 Total Number of Entries = 1 '*' - Configured 2. The PC on 3/1 sends IGMP a report containing the GDA: 239.10.10.10 (see frame 2 below). Shown below is the show ip igmp group command output on the router Router_A.This shows that the router now forwards traffic for 224.10.10.10 to fa0.3 . This is a consequence of the reception of the IGMP report from 10.3.3.2, which is the client PC. Router_A#show ip igmp groups IGMP Connected Group Membership Group Address Interface Uptime Expires Last Reporter 239.10.10.10 Fa0.3 00:02:48 00:02:04 10.3.3.2 Router_A# 3. The router receives the report and sends a CGMP Join message along with the following information:Source MAC: MAC address of routerDest MAC: 01-00-cc-dd-dd-ddContents: MAC address of the client PC (USA): 00-00-0c-07-ac-00 MAC address of the multicast group: 01-00-5e-0a-0a-0a (see frame 3 below)On the router 6d01h: IGMP: Received v2 Report from 10.3.3.2 (Fa0.3) for 239.10.10.10 6d01h: CGMP: Received IGMP Report on Fa0.3 6d01h: from 10.3.3.2 for 239.10.10.10 6d01h: CGMP: Sending Join on Fa0.3 4. The switch with 01-00-cc-dd-dd-dd in the show cam system command output has CGMP enabled. The switch is able to process the packet.The switch makes a lookup in the dynamic CAM table to determine on which port the MAC address of the client PC is located. The 5.