Which option describes how DNS snooping is used on the Cisco ASR 5000?
A.
DNS snooping allows the Cisco ASR 5000 to snoop DNS query packets and compare
against known DNS responses. If a match is found, the Cisco ASR 5000 replies to the query
itself instead of forwarding the query to the destination DNS server.
B.
DNS snooping allows the Cisco ASR 5000 to detect if a DNS response sent back to a
subscriber is valid. If the response is invalid, the Cisco ASR 5000 drops the packet.
C.
DNS snooping allows the Cisco ASR 5000 to enable set of dynamic IP rules to be
installed based on the response to DNS queries sent by a subscriber that matches a
configured domain rule definition. Dynamic IP rules are created for these IP entries within
the same rule that has the domain name, which applies the same charging action to these
dynamic rules.
D.
DNS snooping allows the Cisco ASR 5000 to enable set of dynamic domain rules to be
installed based on the response to DNS queries sent by a subscriber that matches a
configured domain rule definition. Dynamic domain rules are created for the DNS responses
within the same rule that has the domain name, which applies the same charging action to
these dynamic rules.