The function snf_get_link_state() will provide the snf_link_state (SNF_LINK_DOWN or SNF_LINK_UP) for a specific, open device handle. If two ports are merged (with the snf_open() function), it is not possible to obtain its state through snf_get_link_state(). You can, however, use snf_getifaddrs() and retrieve the state of both individual ports.
Please read the Sniffer10G API documentation in the Sniffer10G software release for more details on using these functions.