In a multicast network environment, if IGMPv1 hosts and IGMPv2 routers (hereinafter referred to as version 1 hosts and version 2 routers) are co-located on the same LAN, how do they work together? (Multiple Choice)
A . If there is a version 1 host in the LAN, all hosts must be required to use version 1.
B . Membership reports sent by version 1 hosts are always received by version 2 routers.
C . If a version 1 host exists in a specific group, the version 2 router must ignore any outgoing messages received in that group.
D . Version 2 routers must set a group-related countdown timer that considers the existence of the Version 1 host.
Answer: BCD