This read-only integer reports the maximum number of learned multicast group entries the switch's IGMP table can hold. An administrator checks this to understand how many distinct multicast groups, across all VLANs, the switch can track simultaneously before entries would need to be aged out. For example, a network running many separate IPTV channels as distinct multicast groups would need swIGMPTableMaxEntries large enough to track them all concurrently.