Unsupported Multicast Capability

B.

The Cisco ASA (Adaptive Security Appliance) is a security device that provides firewall, VPN, and other security services for networks. It also provides support for multicast traffic, which is used for applications such as video conferencing, IPTV, and online gaming.

Among the multicast capabilities supported by the Cisco ASA, there is one that is not supported, which is:

A. ASA configured as a rendezvous point

A rendezvous point (RP) is a multicast router that is responsible for forwarding multicast traffic to the members of a multicast group. In Protocol Independent Multicast (PIM), which is a multicast routing protocol, the RP is typically located in the core of the network and is used to distribute multicast traffic from the source to the receivers. However, the Cisco ASA does not support the RP functionality, which means that it cannot act as an RP or forward multicast traffic to an RP.

B. Sending multicast traffic across a VPN tunnel

The Cisco ASA supports the encapsulation of multicast traffic in VPN tunnels using protocols such as GRE (Generic Routing Encapsulation) and IPsec (Internet Protocol Security). This allows multicast traffic to be securely transmitted over the Internet or other public networks. The Cisco ASA can also be used to terminate VPN tunnels that carry multicast traffic.

C. NAT of multicast traffic

The Cisco ASA can perform Network Address Translation (NAT) on multicast traffic, which involves changing the source or destination IP addresses of multicast packets. This is useful in scenarios where the multicast traffic needs to traverse networks with overlapping IP addresses, or when the original multicast source address needs to be hidden.

D. IGMP forwarding (stub) mode

IGMP (Internet Group Management Protocol) is used by hosts to join and leave multicast groups, and by multicast routers to discover which hosts are members of a group. The Cisco ASA supports IGMP forwarding (also known as stub mode), which allows it to act as a multicast router and forward IGMP messages between hosts and multicast routers. This enables the Cisco ASA to participate in PIM-SM (Sparse Mode) multicast routing, which is commonly used in large-scale multicast deployments.

In conclusion, the multicast capability that is not supported by the Cisco ASA appliance is A. ASA configured as a rendezvous point. The Cisco ASA supports sending multicast traffic across a VPN tunnel, NAT of multicast traffic, and IGMP forwarding (stub) mode.