Automatic Multicast Tunneling

Automatic Multicast Tunneling (AMT) provides a method to tunnel multicast data over a unicast network. The tunneling is performed between AMT relays and AMT gateways, using User Datagram Protocol (UDP) encapsulation. AMT enables service providers and their customers to participate in delivering multicast traffic even in the absence of end-to-end multicast connectivity.

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Restrictions for Automatic Multicast Tunneling

  • AMT tunnel only support PIM passive mode on AMT Gateway side.

  • AMT only support SSM modes for PIM signaling.

  • AMT only support ipv4 transport for tunnel.

  • For AMT, auto-rp is invalid between relay and gateway.

Overview

The multicast source sends traffic to the first-hop. Multicast traffic flows through the network until it reaches the last-hop (receivers) or AMT relays. AMT Relay is a multicast router configured to support transit routing between nonmulticast capable internetwork and the native multicast infrastructure.

The following diagram provides a sample AMT network where Relay1 and Relay2 are two AMT relays, which encapsulate the traffic into AMT tunnels, and send one copy to each of the AMT gateways.

Figure 1. Automatic Multicast Tunneling (AMT)



Automatic Multicast Tunneling Message Exchanges

The AMT protocol defines seven message types for control and encapsulation. The message exchanges happen in the following sequence:

  1. Relay Discovery—Gateway sends an AMT discovery message to an anycast address that represents the AMT relay.

  2. Relay Advertisement—Relay responds with an advertisement message, which includes the relay’s unique IP address.

  3. Relay Request—Gateway sends an AMT Request message to the relay using the unique IP address as the destination, along with a nonce to be used for security.

  4. Membership Query—Relay responds with an AMT query that includes the nonce from the AMT request and an opaque security code.

  5. Membership Update—Gateway responds with a membership update that includes an encapsulated IGMPv3/MLDv2 packet.

  6. Teardown—Gateway sends a message to stop the delivery of multicast data messages requested in an earlier membership update message.

  7. After validation the Relay establishes the AMT Tunnel and starts sending multicast traffic [Type 6]. Any further (S,G) uses the same Request/Query/Update - three-way handshake because the tunnel is already established.

AMT Tunnel and Traffic Types

The multicast traffic carried in the AMT tunnel may be IPv4 or IPv6. The AMT tunnel may be setup with IPv4 or IPv6 endpoints, thereby providing the following possibilities.

  • IPv4-in-IPv4—IPv4 multicast traffic carried over an IPv4 tunnel

  • IPv6-in-IPv4—IPv6 multicast traffic carried over an IPv4 tunnel

  • IPv6-in-IPv6—IPv6 multicast traffic carried over an IPv6 tunnel

  • IPv4-in-IPv6—IPv4 multicast traffic carried over an IPv6 tunnel


Note


In Cisco IOS XE Release 3.15S, AMT supports IPv4-in-IPv4 and IPv6-in-IPv4 only.


Advantages of Automatic Multicast Tunneling

  • Simplicity—Instead of incurring the overhead of manually provisioning, establishing and maintaining GRE tunnels between two locations, the receiving network simply sends AMT advertisements to a well-known any-cast prefix. The rest of the tunnel establishment process is done automatically without the need for additional configuration.

  • Resiliency—Because the relay discovery uses an any-cast address, gateways automatically find the closest relay. If that relay becomes unavailable or unreachable, the routing table reconverges on the next closest relay.

  • Efficiency—AMT allows transit routers to perform flow-based load balancing for more efficient link utilization.

Automatic Multicast Tunneling supports IPv4 transport for tunnel and also support for IPv4 multicast traffic & IPv6 multicast traffic. You can also configure AMT relay-only, gateway-only and relay-gateway coexisting modes.

Prerequisites for AMT

  • AMT relay and gateway tunnel requires an interface IP address. However the interface IP addresses do not need to be unique. You can configure the same addresses for the tunnel source address using the ip unnumbered command.

  • You must configure IGMP version 3 on the tunnel interfaces for the SSM to work across tunnels.

  • The tunnel source port and tunnel destination port must be configured to achieve a valid AMT configuration.

Configuration Recommendations for AMT

The tunnel source interface address should be an interface that is set up to be reachable from receivers under all instances. You can use a physical interface address, but it can cause the tunnel to go down if that physical interface is down. A loopback interface is recommended to sustain availability. You do not need a separate loopback address, you can reuse the loopback interface that you usually would have to carry router and router-ID IP address (usually Loopback 0).

IP PIM passive is the recommended and supported mode on AMT interfaces to enable IP multicast routing for AMT tunnel interfaces. This is recommended since no PIM messages (only AMT/IGMP messages) will be sent or received via the AMT tunnel.

On an AMT relay, you need only one tunnel interface to which all gateways can connect. Therefore the interface is a multipoint interface. Every gateway interface can only connect to one relay, but you can configure multiple tunnel interfaces.

Even though AMT tunnels (relay and gateway) only support IPv4 tunnels, the IPv4 tunnels can carry both IPv4 and IPv6 simultaneously. You can configure the AMT for the version(s) of IP that you need.

If you want to set up a redundant AMT relay, your AMT relay address configured on the gateway should be any IP address that you set up as an anycast address on your relays. If you do not plan to use redundant (Anycast) Relay, you can use the relays tunnel source address on the gateways.

If you shut down the anycast Loopback interface, the AMT relay would not accept new AMT gateway tunnel requests. IP routing for the anycast address would only point to any other relays active with the same address and new requests would therefore go to those relays. Any AMT gateways already connected to this relay would stay on this relay, because they already are using the relays interface address.

Enabling and Configuring Automatic Multicast Tunneling on a Relay


Note


Switch-over from active relay to backup relay can take more than 5 minutes.


SUMMARY STEPS

    1.    enable

    2.    configure terminal

    3.    interface tunnel number

    4.    ip address ip-address mask

    5.    no ip redirects

    6.    ip pim sparse-mode

    7.    ip igmp version version number

    8.    ipv6 enable

    9.    tunnel source interface-type interface-number

    10.    tunnel mode udp multipoint

    11.    tunnel dst-port dynamic

    12.    tunnel src-port dynamic

    13.    amt relay traffic {ip | ipv6}

    14.    exit

    15.    ip multicast-routing distributed

    16.    ipv6 multicast-routing

    17.    ip pim ssm {default | range access-list}


DETAILED STEPS
     Command or ActionPurpose
    Step 1enable


    Example:
    Device> enable
     

    Enables privileged EXEC mode.

    • Enter your password if prompted.

     
    Step 2configure terminal


    Example:
    Device# configure terminal
     

    Enters global configuration mode.

     
    Step 3interface tunnel number


    Example:
    Device(config)# interface tunnel 11
     

    Specifies the interface tunnel number and enters interface configuration mode.

     
    Step 4ip address ip-address mask


    Example:
    Device(config-if)# 11.1.1.1 255.255.255.0
     

    Configures the IP address on the interface.

     
    Step 5no ip redirects


    Example:
    Device(config-if)# no ip redirects
     

    Disables sending ICMP Redirect messages.

     
    Step 6ip pim sparse-mode


    Example:
    Device(config-if)# ip pim sparse-mode
     

    Enable PIM sparse-mode operation.

     
    Step 7ip igmp version version number


    Example:
    Device(config-if)# ip igmp version 3
     

    Specifies IGMP version.

     
    Step 8ipv6 enable


    Example:
    Device(config-if)# ipv6 enable
     

    Enables IPv6 on interface.

     
    Step 9tunnel source interface-type interface-number


    Example:
    Device(config-if)# tunnel source loopback 0
     

    Configures tunnel source as a loopback interface.

     
    Step 10tunnel mode udp multipoint


    Example:
    Device(config-if)# tunnel mode udp multipoint
     

    Specifies the UDP encapsulation protocol.

     
    Step 11tunnel dst-port dynamic


    Example:
    Device(config-if)# tunnel dst-port dynamic
     

    Specifies the tunnel destination port.

     
    Step 12tunnel src-port dynamic


    Example:
    Device(config-if)# tunnel src-port dynamic
     

    Specifies the tunnel source port.

     
    Step 13amt relay traffic {ip | ipv6}


    Example:
    Device(config-if)# amt relay traffic ipv6
     

    Enables IPv4 or IPv6 traffic on AMT relay interface.

     
    Step 14exit


    Example:
    Device(config-if)# exit
     

    Exits interface configuration mode and returns to global configuration mode.

     
    Step 15ip multicast-routing distributed


    Example:
    Device(config)# ip multicast-routing distributed
     

    Enables Multicast Distributed Switching (MDS).

     
    Step 16ipv6 multicast-routing


    Example:
    Device(config)# ipv6 multicast-routing
     

    Enables multicast routing using Protocol Independent Multicast (PIM) and Multicast Listener Discovery (MLD).

     
    Step 17ip pim ssm {default | range access-list}


    Example:
    Device(config)# ip pim ssm default
     

    Specifies the Source Specific Multicast (SSM) range of IP multicast addresses.

     

    Enabling and Configuring Automatic Multicast Tunneling on Gateway

    SUMMARY STEPS

      1.    enable

      2.    configure terminal

      3.    interface tunnel number

      4.    ip address ip-address mask

      5.    ip pim passive

      6.    ip igmp version version number

      7.    ipv6 enable

      8.    ipv6 pim passive

      9.    tunnel source interface-type interface-number

      10.    tunnel mode udp ip

      11.    tunnel destination dynamic

      12.    tunnel dst-port dynamic

      13.    tunnel src-port dynamic

      14.    amt gateway traffic {ip | ipv6}

      15.    amt gateway relay-address IP address

      16.    exit

      17.    ip multicast-routing distributed

      18.    ipv6 multicast-routing

      19.    ip pim ssm {default | range access-list}

      20.    ipv6 multicast pim-passive-enable

      21.    ip route ip-address interface-type interface-number [multicast]

      22.    ipv6 route ipv6-prefix/prefix-length interface-type interface-number [multicast]


    DETAILED STEPS
       Command or ActionPurpose
      Step 1enable


      Example:
      Device> enable
       

      Enables privileged EXEC mode.

      • Enter your password if prompted.

       
      Step 2configure terminal


      Example:
      Device# configure terminal
       

      Enters global configuration mode.

       
      Step 3interface tunnel number


      Example:
      Device(config)# interface tunnel 11
       

      Specifies the interface tunnel number and enters interface configuration mode.

       
      Step 4ip address ip-address mask


      Example:
      Device(config-if)# 11.1.1.1 255.255.255.0
       

      Configures the IP address on the interface.

       
      Step 5ip pim passive


      Example:
      Device(config-if)# ip pim passive
       

      Enables IP PIM passive mode operation.

       
      Step 6ip igmp version version number


      Example:
      Device(config-if)# ip igmp version 3
       

      Specifies IGMP version.

       
      Step 7ipv6 enable


      Example:
      Device(config-if)# ipv6 enable
       

      Enables IPv6 on interface.

       
      Step 8ipv6 pim passive


      Example:
      Device(config-if)# ipv6 pim passive
       

      Enables IPv6 PIM passive mode operation.

       
      Step 9tunnel source interface-type interface-number


      Example:
      Device(config-if)# tunnel source loopback 0
       

      Configures tunnel source as a loopback interface.

       
      Step 10tunnel mode udp ip


      Example:
      Device(config-if)# tunnel mode udp ip
       

      Specifies the UDP encapsulation protocol.

       
      Step 11tunnel destination dynamic


      Example:
      Device(config-if)# tunnel destination dynamic
       

      Applies the tunnel destination address dynamically to the tunnel interface.

       
      Step 12tunnel dst-port dynamic


      Example:
      Device(config-if)# tunnel dst-port dynamic
       

      Applies the tunnel destination port dynamically.

       
      Step 13tunnel src-port dynamic


      Example:
      Device(config-if)# tunnel src-port dynamic
       

      Applies the tunnel source port dynamically.

       
      Step 14amt gateway traffic {ip | ipv6}


      Example:
      Device(config-if)# amt gateway traffic ipv6
       

      Enables IPv4 or IPv6 traffic on AMT gateway interface.

       
      Step 15amt gateway relay-address IP address


      Example:
      Device(config-if)# amt gateway relay-address 172.16.0.0
       

      Specifies the destination IP address of AMT discovery.

       
      Step 16exit


      Example:
      Device(config-if)# exit
       

      Exits interface configuration mode and returns to global configuration mode.

       
      Step 17ip multicast-routing distributed


      Example:
      Device(config)# ip multicast-routing distributed
       

      Enables Multicast Distributed Switching (MDS).

       
      Step 18ipv6 multicast-routing


      Example:
      Device(config)# ipv6 multicast-routing
       

      Enables multicast routing using Protocol Independent Multicast (PIM) and Multicast Listener Discovery (MLD).

       
      Step 19ip pim ssm {default | range access-list}


      Example:
      Device(config)# ip pim ssm default
       

      Specifies the Source Specific Multicast (SSM) range of IP multicast addresses.

       
      Step 20ipv6 multicast pim-passive-enable


      Example:
      Device(config)# ipv6 multicast pim-passive-enable
       

      Enables passive PIM operation.

       
      Step 21ip route ip-address interface-type interface-number [multicast]


      Example:
      Device(config)# ip route 101.0.0.2 255.255.255.255 tunnel10 multicast
       

      Specifies the IP address along with interface type, interface number, and multicast route.

       
      Step 22ipv6 route ipv6-prefix/prefix-length interface-type interface-number [multicast]


      Example:
      Device(config)# ipv6 route 2011::101:0:0:2/128 Tunnel10 multicast
       

      Specifies the IPv6 prefix and length along with interface type, interface number, and multicast route (route only usable by multicast).

       

      Displaying and Verifying AMT Configuration

      Before You Begin
      SUMMARY STEPS

        1.    ping 3.3.3.3 source 5.5.5.5

        2.    show ip igmp membership

        3.    show ip mroute

        4.    show ip rpf10.3.3.1


      DETAILED STEPS
        Step 1   ping 3.3.3.3 source 5.5.5.5


        Example:
        Device# ping 3.3.3.3 source 5.5.5.5
           Type escape sequence to abort.
           Sending 5, 100-byte ICMP Echos to 3.3.3.3, timeout is 2 seconds:
           Packet sent with a source address of 5.5.5.5
           !!!!!
           Success rate is 100 percent (5/5), round-trip min/avg/max = 6/6/8 ms

        Ping the relay tunnel source address from the gateway, using the gateways tunnel source address and the gateway address (if both are different as the example).

        Step 2   show ip igmp membership


        Example:
        Device# show ip igmp membership
          ...
           Channel/Group                  Reporter        Uptime   Exp.  Flags  Interface
          /*,232.2.3.4                    0.0.0.0         00:03:02 stop  2MA    Lo0
           10.3.3.1,232.2.3.4                             00:03:02 stop  A      Lo0
        Note   

        The command is executed at destination gateway.

        You can use the ip igmp static-group command, you create an IGMP membership request on the interface. You can do this on any physical interface configured for IP multicast, but if there are multiple routers attached to the interface, then the AMT gateway router may not become the PIM-DR and therefore not join to the multicast traffic. It can therefore be easier to put the join on an existing loopback interface and also enable it for IP multicast (IP PIM passive).

        Step 3   show ip mroute


        Example:
        Device# show ip mroute
          ...
          (10.3.3.1, 232.2.3.4), 00:01:53/00:01:08, flags: sTI
            Incoming interface: Tunnel1, RPF nbr 0.0.0.0, Mroute
            Outgoing interface list:
              Loopback0, Forward/Sparse-Dense, 00:01:51/00:01:08
        Note   

        The command is executed at destination gateway.

        The AMT gateway will join the multicast traffic towards the AMT relay if the mroute shows the incoming interface as the Tunnel interface and when it is joined for example, when there are one or more outgoing interfaces.

        When the command is executed on the source gateway, the mroute state on the relay will show the relay interface as an adjacency in the outgoing interface list. Because there is one interface for all joining relays, each outgoing copy across the AMT relay interface is identified by the AMT relay interface, the IP address of the gateway and the UDP port number of the relay as seen by the relay. If there are multiple gateways in a home behind a NAT/PAT (single IP address to the internet), there would be multiple adjacencies shown with the same gateway IP address, but different UDP ports. If state is not built as expected, you can use debug ip igmp to troubleshoot it. There are no additional AMT debugs for the AMT/IGMP joins, instead those are all part of IGMP debugs.

        Step 4   show ip rpf10.3.3.1


        Example:
        Device#
        RPF information for ? (10.3.3.1)
          RPF interface: Tunnel1
          RPF neighbor: ? (0.0.0.0)
          RPF route/mask: 10.3.3.0/24
          RPF type: multicast (static)
          Doing distance-preferred lookups across tables
          RPF topology: ipv4 multicast base
        
        Note   

        The command is executed at destination gateway.

        Verifies Multicast RPF.

        If the output is not showing the desired AMT gateway tunnel interface as the RPF interface, then your routing configuration for IP multicast into the AMT tunnel is not set up correctly. If you have only one AMT gateway interface, you can use a static mroute. If you have multiple AMT tunnel for different relays, you need to configure the source prefixes (and RP-addresses when you use PIM-SM) towards their respective AMT tunnel.

        For IP multicast tree to flow correctly via the AMT tunnels, you must first check if the IP multicast state is correctly built from gateway to relay. This primarily means that the (S,G) join for a source in PIM-SSM/PIM-SM or the (*,G) join to the RP address in PIM-SM need to RPF towards the desired AMT gateway tunnel.


        Displaying and Verifying AMT Relay Configuration

        SUMMARY STEPS

          1.    enable

          2.    show ip amt tunnel

          3.    show ip mroute section [group-address]

          4.    show ipv6 mroute section [group-address]

          5.    show ip mfib section [group-address]

          6.    show ipv6 mfib section [group-address]

          7.    show platform software ip rp active mfib section [group-address]

          8.    show platform software ipv6 rp active mfib section [group-address]

          9.    show platform software mlist rp active index multicast-index-number

          10.    show platform software adjacency rp active index platform-allocated-index-value

          11.    show ip interface brief


        DETAILED STEPS
          Step 1   enable


          Example:
          Device> enable

          Enables privileged EXEC mode.

          • Enter your password if prompted.

          Step 2   show ip amt tunnel


          Example:
          Device# show ip amt tunnel
          
          AMT Relay tunnel:
              Local address       UDP port
                11.11.11.11       2268 (0x8DC )
              Remote address                      Expire time
                33.33.33.33       59464(0xE848)   00:03:07
              Connected to 1 Gateway
          
            Total active Gateways: 1
          
          Displays AMT relay configuration.
          Step 3   show ip mroute section [group-address]


          Example:
          Device# show ip mroute section 232.1.1.1
          
          (101.0.0.2, 232.1.1.1), 2d00h/00:02:18, flags: sTI
            Incoming interface: GigabitEthernet0/0/4, RPF nbr 0.0.0.0
            Outgoing interface list:
              Tunnel10, 33.33.33.33, UDP port 59464, Forward/Sparse, 2d00h/00:02:18
          Displays information about sparse mode routes in the IP multicast routing (mroute) table for the specified multicast group.
          Step 4   show ipv6 mroute section [group-address]


          Example:
          Device# show ipv6 mroute section 232.1.1.1
          
          (2011::101:0:0:2, FF3F::232:1:1:1), 2d00h/never, flags: sTI
            Incoming interface: GigabitEthernet0/0/4
            RPF nbr: 2011::101:0:0:2
            Immediate Outgoing interface list:
              Tunnel10, AMT NH 33.33.33.33, UDP Port 59464, Forward, 2d00h/never
          
          Displays information about sparse mode routes in the IPv6 mroute table for the specified multicast group.
          Step 5   show ip mfib section [group-address]


          Example:
          Device# show ip mfib section 232.1.1.1
          
          (101.0.0.2,232.1.1.1) Flags: HW
             SW Forwarding: 0/0/0/0, Other: 0/0/0
             HW Forwarding:   NA/NA/NA/NA, Other: NA/NA/NA
             GigabitEthernet0/0/4 Flags: A
             Tunnel10, AMT Encap 33.33.33.33, UDP Port:59464 Flags: F NS
               Pkts: 0/0
          Displays the status of entries and interfaces in the IPv4 Multicast Forwarding Information Base (MFIB) for the specified multicast group.
          Step 6   show ipv6 mfib section [group-address]


          Example:
          Device# show ipv6 mfib section 232.1.1.1
           
          (2011::101:0:0:2,FF3F::232:1:1:1) Flags: HW
             SW Forwarding: 0/0/0/0, Other: 0/0/0
             HW Forwarding:   NA/NA/NA/NA, Other: NA/NA/NA
             GigabitEthernet0/0/4 Flags: A
             Tunnel10, AMT Encap 33.33.33.33, UDP Port:59464 Flags: F NS
               Pkts: 0/0
          
          Displays the status of entries and interfaces in the IPv6 Multicast Forwarding Information Base (MFIB) for the specified multicast group.
          Step 7   show platform software ip rp active mfib section [group-address]


          Example:
          Device# show platform software ip rp active mfib section 232.1.1.1
          
          232.1.1.1, 101.0.0.2/64 --> OBJ_INTF_LIST (0x5a)
                          Obj id: 0x5a, Flags:
                          OM handle: 0x421712c4
          Displays platform software IPv4 MFIB route processor information for the specified multicast group.
          Step 8   show platform software ipv6 rp active mfib section [group-address]


          Example:
          Device# show platform software ipv6 rp active mfib section 232.1.1.1
          
          ff3f::232:1:1:1, 2011::101:0:0:2/256 --> OBJ_INTF_LIST (0x5b)
                          Obj id: 0x5b, Flags:
                          OM handle: 0x42171d24
          
          Displays platform software IPv6 MFIB route processor information for the specified multicast group.
          Step 9   show platform software mlist rp active index multicast-index-number


          Example:
          Device# show platform software mlist rp active index 0x5a
          
          OCE              Type             OCE Flags        Interface
          --------------------------------------------------------------------------------------
          0x57             OBJ_ADJACENCY    NS, F            Tunnel10
          0xf80000c1       OBJ_ADJACENCY    A                GigabitEthernet0/0/4
          Displays platform software route processor information for the specified multicast list index.
          Step 10   show platform software adjacency rp active index platform-allocated-index-value


          Example:
          Device# show platform software adjacency rp active index 0x57
          
          Number of adjacency objects: 22
          
          Adjacency id: 0x57 (87)
            Interface: Tunnel10, IF index: 20, Link Type: MCP_LINK_IP
            Encap: 45:0:0:0:0:0:0:0:ff:11:63:95:b:b:b:b:21:21:21:21:8:dc:e8:48:0:0:0:0:6:0
            Encap Length: 30, Encap Type: MCP_ET_TUNNEL, MTU: 1470
            Flags: no-l3-inject
            Incomplete behavior type: None
            Fixup: gre
            Fixup_Flags_2: pmip-udp
            Nexthop addr: 33.33.33.33
            IP FRR MCP_ADJ_IPFRR_NONE 0
            OM handle: 0x4217013c
          
          Displays platform software adjacency route processor information for the specified platform allocated index.
          Step 11   show ip interface brief


          Example:
          Device(source gateway)# show ip interface brief
          
            Interface              IP-Address      OK? Method Status                Protocol
              Tunnel1                3.3.3.3         YES TFTP   up                    up
              ....
          
          

          The above output indicates that the relay has no connection from a gateway. The AMT relay interface will be up after it is correctly configured. If the output displays Protocol "down", you must check your configuration. If the interface command shows administratively down, you have not configured the "no shut" in the interface.

          Displays errors in AMT gateway configuration.

          Displaying and Verifying AMT Gateway Configuration

          SUMMARY STEPS

            1.    enable

            2.    show ip amt tunnel

            3.    show ip mroute section [group-address]

            4.    show ipv6 mroute section [group-address]

            5.    show ip mfib section [group-address]

            6.    show ipv6 mfib section [group-address]

            7.    show platform software adjacency rp active index platform-allocated-index-value

            8.    show ip interface brief


          DETAILED STEPS
            Step 1   enable


            Example:
            Device> enable

            Enables privileged EXEC mode.

            • Enter your password if prompted.

            Step 2   show ip amt tunnel


            Example:
            Device(destination gateway)# show ip amt tunnel
            
            AMT Gateway tunnel Tunnel1:
                   Local address       UDP port
                        5.5.5.5           54358(0xD456)
                   Remote address
                        3.3.3.3           2268 (0x8DC )
            
              Total active Relays: 1
            
            Device(source gateway)# show ip amt tunnel 
            AMT Relay tunnel:
                  Local address       UDP port
                    3.3.3.3           2268 (0x8DC )
                  Remote address                      Expire time
                    5.5.5.5           54358(0xD456)   00:03:53
                  Connected to 1 Gateway

            The above output is displayed if both relay and gateway is working correctly.

            Displays AMT gateway configuration.
            Step 3   show ip mroute section [group-address]


            Example:
            Device# show ip mroute section 232.1.1.1
            
            (101.0.0.2, 232.1.1.1), 2d00h/00:02:54, flags: sTI
              Incoming interface: Tunnel10, RPF nbr 0.0.0.0, Mroute
              Outgoing interface list:
                GigabitEthernet0/0/4, Forward/Sparse, 2d00h/00:02:54
            Displays information about the IP multicast routing (mroute) table for the specified multicast group.
            Step 4   show ipv6 mroute section [group-address]


            Example:
            Device# show ipv6 mroute section 232.1.1.1
            
            (2011::101:0:0:2, FF3F::232:1:1:1), 2d00h/never, flags: sTI
              Incoming interface: Tunnel10
              RPF nbr: ::
              Immediate Outgoing interface list:
                GigabitEthernet0/0/4, Forward, 2d00h/never
            
            Displays information about the IPv6 mroute table for the specified multicast group.
            Step 5   show ip mfib section [group-address]


            Example:
            Device# show ip mfib section 232.1.1.1
            
            (101.0.0.2,232.1.1.1) Flags: HW
               SW Forwarding: 0/0/0/0, Other: 0/0/0
               HW Forwarding:   NA/NA/NA/NA, Other: NA/NA/NA
               Tunnel10 Flags: A
               GigabitEthernet0/0/4 Flags: F NS
                 Pkts: 0/0
            Displays the entries and interfaces in the IPv4 Multicast Forwarding Information Base (MFIB) for the specified multicast group.
            Step 6   show ipv6 mfib section [group-address]


            Example:
            Device# show ipv6 mfib section 232.1.1.1
             
            (2011::101:0:0:2,FF3F::232:1:1:1) Flags: HW
               SW Forwarding: 0/0/0/0, Other: 0/0/0
               HW Forwarding:   NA/NA/NA/NA, Other: NA/NA/NA
               Tunnel10 Flags: A
               GigabitEthernet0/0/4 Flags: F NS
                 Pkts: 0/0
            
            Displays the entries and interfaces in the IPv6 Multicast Forwarding Information Base (MFIB) for the specified multicast group.
            Step 7   show platform software adjacency rp active index platform-allocated-index-value


            Example:
            Device# show platform software adjacency rp active index 0x57
            
            Number of adjacency objects: 19
            Adjacency id: 0xf8000126 (4160749862)
              Interface: Tunnel10, IF index: 18, Link Type: MCP_LINK_IP
              Encap: 45:0:0:0:0:0:0:0:ff:11:63:95:21:21:21:21:b:b:b:b:e8:48:8:dc:0:0:0:0:6:0
              Encap Length: 30, Encap Type: MCP_ET_TUNNEL, MTU: 1470
              Incomplete behavior type: None
              Fixup: gre
              Fixup_Flags_2: pmip-udp
              IP FRR MCP_ADJ_IPFRR_NONE 0
              OM handle: 0x4216aaf4
            
            Displays platform software adjacency route processor information for the specified platform allocated index.
            Step 8   show ip interface brief


            Example:
            Device(destination gateway)# show ip interface brief
            
              Interface              IP-Address      OK? Method Status                Protocol
              Tunnel1                5.5.5.5         YES TFTP   up                    down
            
            
            The Protocol: down displayed in the above output indicates that the gateway has no connection to the relay. If the interface command shows administratively down, you have not configured the "no shut" in the interface. If the command displays UNKNOWN but Protocol shows "up", then the gateway did have a connection to the relay hat was terminated.
            Note   

            It takes a few minutes before a gateway will consider a relay to be unreachable after not receiving packets from it. The gateway will then revert trying to reach the anycast address to find a new relay (in case the existing relay is down).

            Displays errors in AMT gateway configuration.

            Example: AMT Relay Configuration

            The following example shows how to configure AMT relay:
            enable 
            configure terminal 
            interface Tunnel10
             ip address 11.1.1.1 255.255.255.0
             no ip redirects
             ip pim sparse-mode
             ip igmp version 3
             ipv6 enable
             tunnel source Loopback0
             tunnel mode udp multipoint
             tunnel dst-port dynamic
             tunnel src-port dynamic
             amt relay traffic ip
             amt relay traffic ipv6
            exit
            
            ip multicast-routing distributed
            ipv6 multicast-routing
            ip pim ssm default
            end

            Example: AMT Gateway Configuration

            The following example shows how to configure AMT gateway:
            enable 
            configure terminal 
            interface Tunnel10
             ip address 33.1.1.1 255.255.255.0
             ip pim passive
             ip igmp version 3
             ipv6 enable
             ipv6 pim passive
             tunnel source Loopback0
             tunnel mode udp ip
             tunnel destination dynamic
             tunnel dst-port dynamic
             tunnel src-port dynamic
             amt gateway traffic ip
             amt gateway traffic ipv6
             amt gateway relay-address 167.3.0.1
            exit
            
            ip multicast-routing distributed
            ipv6 multicast-routing
            ip pim ssm default
            ipv6 multicast pim-passive-enable
            ip route 101.0.0.2 255.255.255.255 Tunnel10 multicast
            ipv6 route 2011::101:0:0:2/128 Tunnel10 multicast
            end

            Additional References for Automatic Multicast Tunneling

            Related Documents

            Related Topic

            Document Title

            Cisco IOS commands

            Cisco IOS Master Commands List, All Releases

            IP Multicast commands

            Cisco IOS IP Multicast Command Reference

            Technical Assistance

            Description

            Link

            The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password.

            http:/​/​www.cisco.com/​cisco/​web/​support/​index.html

            Feature Information for Automatic Multicast Tunneling

            The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.

            Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/​go/​cfn. An account on Cisco.com is not required.
            Table 1 Feature Information for Automatic Multicast Tunneling

            Feature Name

            Releases

            Feature Information

            Automatic Multicast Tunneling

            Cisco IOS XE Release 3.15S

            Automatic Multicast Tunneling (AMT) provides a method to tunnel multicast data over a unicast network. The tunneling is performed between AMT relays and AMT gateways, using User Datagram Protocol (UDP) encapsulation.

            In Cisco IOS XE Release 3.15S, this feature was introduced on Cisco ASR 1000 Series Aggregation Services Routers.

            The following commands were introduced or modified by this feature: amt gateway traffic ip, amt gateway traffic ipv6, amt gateway relay-address, amt relay traffic ip, amt relay traffic ipv6, show ip amt tunnel, show ip amt vrf, show ipv mfib detail, show ipv6 mfib detail, show ip mroute detail, show ipv6 mroute detail, show platform software adjacency fp active, show platform software adjacency rp active, show platform software ip rp active mfib, show platform software ip fp active mfib, show platform software ipv6 rp active mfib, show platform software ipv6 fp active mfib, show platform software mlist.