Cisco Support Community Expert Series Webcast Multicast on

• Today’s featured expert is Cisco Support Engineer Maithri Bhagavan • Ask her

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Are you planning to implement Multicast on your Wireless Network? a) I have already implemented it b) I am looking to implement it soon c) I would like to learn more about it © 2011 Cisco and/or its affiliates. All rights reserved. 6

Use the Q&A panel to submit your questions. Experts will start responding those ©

Maithri Bhagavan Customer Support Engineer December 18 th, 2012 © 2011 Cisco and/or its

v How multicast works on Cisco WLCs v Configuration required to support multicast. v Troubleshooting common issues Note: All the terms explained in this presentation are w. r. t multicast on wireless and has limited info on wired multicast. © 2011 Cisco and/or its affiliates. All rights reserved. 9

ü Why do we need Wireless multicast? ü Modes of MCAST ü How Multicast works? ü Broadcast Forwarding ü IGMP Snooping ü Guidelines for using Multicast ü Configuration on WLC ü Wired Configuration ü Troubleshooting Multicast © 2011 Cisco and/or its affiliates. All rights reserved. 10

• More and more customers are implementing BYOD in their networks • With the increase in BYOD deployments, it becomes necessary that the Wireless network is capable of supporting different types of clients devices and the features they use. • Some of the most commonly used BYOD devices today are i. Pad’s, i. Phones etc which work via Bonjour (uses Multicast IP 224. 0. 0. 251) and needs multicast • Other common applications of wireless multicast are media streaming in educational institutions and large enterprises, audio and video conferencing and file sharing © 2011 Cisco and/or its affiliates. All rights reserved. 11

u. IP multicast was introduced on CUWN release 3. 2 onwards u. There are

Unicast • In this mode, WLC forwards multicast traffic to all the APs associated to it by making copies of the multicast packet and sending it to each AP • Depending on the number of APs connected, the controller has to replicate the packets for each CAPWAP tunnel • This can consume lot of processing power and hence cause an overhead on the controller • It also floods the network with large number of duplicate unicast packets. © 2011 Cisco and/or its affiliates. All rights reserved. 13

Multicast • Instead of using unicast to send each packet across CAPWAP tunnel to each AP, LWAPP AP multicast group feature was used. • Via this feature, the controller sends all the multicast traffic to the multicast group IP. • APs send an IGMP join request to join the MCAST group and will start receiving the traffic • In an LWAPP multicast group, the controller becomes the mcast source and the APs become the mcast receivers • The APs in an LWAPP multicast group accept IGMP queries only from the controller that it is associated to © 2011 Cisco and/or its affiliates. All rights reserved. 14

Multicast © 2011 Cisco and/or its affiliates. All rights reserved. 15

• When the controller receives a multicast packet from any of the client VLANs on the first hop router, it transmits the packet to the LWAPP multicast group via the management interface • The multicast-enabled network delivers the LWAPP multicast packet to each of the access points that have joined the LWAPP multicast group • If more than one WLAN is associated to the VLAN interface where the original multicast packet was sourced, the AP transmits the multicast packet over each WLAN © 2011 Cisco and/or its affiliates. All rights reserved. 16

• The multicast packet is unicast (CAPWAP encapsulated) from the AP to the controller similar to standard wireless client traffic. • The controller makes two copies of the multicast packet. One copy is sent out the VLAN associated with the WLAN it came on, enabling receivers on the wired LAN to receive the multicast stream and the router to learn about the new multicast group. • The second copy of the packet is LWAPP-encapsulated and is sent to the LWAPP multicast group so that wireless clients may receive the multicast stream. © 2011 Cisco and/or its affiliates. All rights reserved. 17

• Tells the controller how to handle the broadcast packets that the controller receives • If broadcast forwarding is enabled on the controller and multicast mode is set to unicast, then the broadcast packets will also be sent as unicast to each AP • When broadcast forwarding is enabled on the controller and multicast-multicast mode is enabled, the broadcast packets will also use the LWAPP AP multicast group IP to send the packets © 2011 Cisco and/or its affiliates. All rights reserved. 18

• IGMP snooping support was introduced in CUWN release 4. 2 onwards. • Using this, the controller gathers IGMP reports from all the clients who request traffic from the mcast group • The WLC analyzes these reports and creates a unique MGID for each mcast group and vlan number. • These reports have a source address as the interface address of the VLAN • An access point MGID table is created on all APs associated to the controller along with the client mac addresses. © 2011 Cisco and/or its affiliates. All rights reserved. 19

• When the controller receives multicast traffic for a specific group, it will forward it to all the APs • When IGMP Snooping is enabled, only those APs that have clients listening on that group will forward the traffic on that WLAN • L 3 mcast packets are forwarded with a MGID that is unique for the ingress vlan and the mcast group. • L 2 mcast is fwded with a MGID that is unique for the ingress interface © 2011 Cisco and/or its affiliates. All rights reserved. 20

© 2010 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 21

© 2010 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 22

• Cisco recommends to use MCAST addresses from the block 239/8 which is the reserved block of mcast IPs for using in private multicast domains • Do not use the address range 239. 0. 0. X or 239. 128. 0. X as it overlaps with link local mac addresses • LWAPP multicast address configured should be different for each controller in the network • Multicast applications should not use UDP port numbers 12222, 12223 and 12224 as the WLC will drop any mcast traffic sent to these ports © 2011 Cisco and/or its affiliates. All rights reserved. 23

• From the GUI, go to Controller General Tab to enable multicast • Depending on requirement, you can set the mode to multicast- unicast or multicast-multicast mode • If choosing multicast-multicast mode, then enter the multicast group IP address • Make sure Broadcast Forwarding is also enabled • Under Controller -> Multicast option, enable the “Global Multicast Mode” and “IGMP snooping” option © 2011 Cisco and/or its affiliates. All rights reserved. 24

© 2011 Cisco and/or its affiliates. All rights reserved. 25

© 2011 Cisco and/or its affiliates. All rights reserved. 26

• Wireless multicast will work only if the wired side is also configured correctly to allow the multicast traffic • Enable multicast on all the L 3 hops between the source and the destination. This can be done using the IOS command “ip multicast-routing distributed” in global config mode • Make sure IP multicast is enabled on all the required L 3 interfaces • This includes the multicast source vlan, the destination client vlan, the AP vlan and the controller management vlan • We can use dense mode or sparse-dense mode depending on the network design • For a simple setup we can just enable the “pim dense mode” © 2011 Cisco and/or its affiliates. All rights reserved. 27

Switch#config t Enter configuration commands, one per line. End with CNTL/Z. Switch(config)#ip multicast-routing distributed Switch(config)#interface range vlan 10 - 30 Switch(config-if-range)#ip pim dense-mode Switch#show ip pim interface Address Interface Ver/ Nbr Query DR DR Mode Count Intvl Prior 10. 10. 10 Vlan 10 v 2/D 0 30 1 10. 10. 10 20. 20. 20 Vlan 20 v 2/D 0 30 1 20. 20. 20 30. 30. 30 Vlan 30 v 2/D 0 30 1 30. 30. 30 © 2011 Cisco and/or its affiliates. All rights reserved. 28

• Once multicast is enabled we can use the following commands to verify: show run | i multicast show ip mroute • IGMP snooping is enabled by default on Cisco switches. But in case it is disabled, it can be enabled using the IOS command “ip igmp snooping” in the global config mode © 2011 Cisco and/or its affiliates. All rights reserved. 29

What is your level of experience with troubleshooting Wireless Multicast? a) I know the concepts well and know where to look for the issue b) I know the basic concepts and research further online to get more info and try to fix it c) I am not very familiar with it and open a TAC case if I need assistance d) I have never tried this before © 2011 Cisco and/or its affiliates. All rights reserved. 30

• Isolating the issue • Troubleshooting on wired side • Troubleshooting on WLC

• When we are not receiving multicast stream over wireless first we need to isolate if the issue is on the wired side or the wireless side • We can verify this by keeping both the source and the destination as wired devices and test if it works • In case the wired multicast is not working then we need to check the configs at each and every hop between the source and the destination to make sure multicast is enabled correctly • We can use the verification commands below to verify this: Commands: show ip pim interface show ip mroute show ip igmp © 2011 Cisco and/or its affiliates. All rights reserved. 32

• If multicast works on the wired side but not on the wireless, we need to check it is enabled correctly on all concerned wireless subnets • Make sure the controller is configured correctly for multicast and igmp snooping is enabled • If there are multiple controllers in the network, it is recommended to use a unique multicast address on each WLC • Isolate the issue by reducing the number of hops between source and destination, with only one or few devices in between and then source the traffic to test if it works • Test by placing multicast source and destination in different vlans • Make sure P 2 P blocking is disabled on the WLAN © 2011 Cisco and/or its affiliates. All rights reserved. 33

• To verify multicast mode: show network • To check L 2 and L 3 MGIDs: show network multicast mgid summary show network multicast mgid detail <mgid> • Important debugs: debug bcast * enable © 2011 Cisco and/or its affiliates. All rights reserved. 34

• At times there are issues with the client devices itself where they do not send IGMP reports causing multicast to fail. In these cases, it is best to analyze a packet capture taken from the client to check if the client is sending IGMP reports or not • To verify if it is an application specific issue, we can use a different mcast source or an external mcast traffic generating device. • We can install the traffic generator on a PC that will source continuous traffic to the multicast group mentioned and a mcast receiver on another PC can join the group to confirm if it is receiving the traffic. The traffic can be analyzed via a sniffing tool like Wireshark © 2011 Cisco and/or its affiliates. All rights reserved. 35

© 2011 Cisco and/or its affiliates. All rights reserved. 36

© 2011 Cisco and/or its affiliates. All rights reserved. 37

Was this session helpful in clarifying your queries on Wireless Multicast? a) Have additional questions b) It helped me understand the concepts but need more detailed explanation c) Yes it helped me and I can now implement this in my network © 2011 Cisco and/or its affiliates. All rights reserved. 38

• http: //www. cisco. com/en/US/tech/tk 722/tk 809/technologies_config uration_example 09186 a 00807 cc 10 d. shtml • http: //www. cisco. com/en/US/docs/solutions/Enterprise/Mobility/em ob 41 dg/ch 6_Mcst. html • http: //www. cisco. com/en/US/products/hw/wireless/ps 4570/product s_tech_note 09186 a 0080 bb 1 d 7 c. shtml © 2011 Cisco and/or its affiliates. All rights reserved. 40

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Polish Topic: WAN Acceleration and Optimization Techniques Using Cisco WAAS Tuesday January 8 ‘ 2013, at 10 a. m. Warsaw Time (CEST) Join Cisco Expert: Gabriel Kujawski • During the live event, Cisco subject matter expert will introduce techniques of WAN acceleration and optimization applications using the Cisco WAAS solution. Register at http: //tools. cisco. com/gems/customer. QA. do? METH OD=E&LANGUAGE_ID=L&SEMINAR_CODE=S 17561 &PRIORITY_CODE=cisco © 2011 Cisco and/or its affiliates. All rights reserved. 44

Japanese Topic: Fabric. Path Refresher: From Fundamental to Virtual Port-Channel Plus (v. PC+) Tuesday, January 29, 2013, at 10 a. m. JST Tokyo Join Cisco Expert: Kaoru Yamashita During the live event, Cisco subject matter expert Kaoru Yamashita will discuss Fabric. Path, a specific protocol for new Layer 2 network overcoming weakness of Spanning Tree Protocol (STP). Register at http: //tools. cisco. com/gems/customer. Site. do? MET HOD=E&LANGUAGE_ID=J&SEMINAR_CODE=S 1756 4&PRIORITY_CODE=cisco © 2011 Cisco and/or its affiliates. All rights reserved. 45

Topic: Configuring and Troubleshooting MPLS Traffic Engineering with Cisco Expert Saurabh Chopra Tuesday, December 18, at 9 a. m. PST (San Francisco) Where: http: //www. facebook. com/Cisco. Support. Community More Info: https: //www. facebook. com/events/473508526025670/ © 2011 Cisco and/or its affiliates. All rights reserved. 46

Topic: Data Center and Cloud Security Join Cisco Expert: Naman Latif Learn about different solutions and best practices around securing your physical and virtual environment in the Data Center Ends December 21 Topic: Cisco Unified Border Element (UBE) Enterprise Join Cisco Experts: Robin Cai Learn and ask questions about how to design and troubleshoot for Cisco Unified Border Element configurations for the enterprise in different call scenarios, including normal calls, hold/resume, call transfer, call forwarding. Ends December 21 Join the discussion for these Ask The Expert Events at: https: //supportforums. cisco. com/community/netpro/expert-corner#view=ask-the-experts © 2011 Cisco and/or its affiliates. All rights reserved. 47

If you speak Spanish, Portuguese, Japanese, Polish or Russian, we invite you to ask your questions and collaborate in your language: • Spanish https: //supportforums. cisco. com/community/spanish • Portuguese https: //supportforums. cisco. com/community/portuguese • Japanese https: //supportforums. cisco. com/community/csc-japan • Polish https: //supportforums. cisco. com/community/etc/netpro-polska • Russian https: //supportforums. cisco. com/community/russian © 2011 Cisco and/or its affiliates. All rights reserved. 48

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What is the connection between Cisco WLAN controllers and Apple? To cope with the rising tide of i. OS devices trying to use Apple's Bonjour discovery protocol on enterprise networks, Cisco introduced its next-generation wireless LAN products. The Cisco Aironet® 1200 Series is the industry's first dual radio wireless LAN access point that supports both IEEE 802. 11 b and the 5 -GHz IEEE 802. 11 a radios. (Apr 02) This protocol enables Apple devices to query and announce specific services such as Air. Play which allows audio and video to be shared between devices dynamically. More Information: http: //www. cisco. com/en/US/products/hw/wireless/ps 4570/products_tec h_note 09186 a 0080 bb 1 d 7 c. shtml © 2011 Cisco and/or its affiliates. All rights reserved. 50

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