hh3cMcsL2EntryPortAttribute
1.3.6.1.4.1.25506.2.123.1.3.1.8
Attribute of the port. 'd' means learned from IGMP/MLD packets,
's' means configured statically, 'p' means learned from PIM snooping,
'k' means obtained from the kernel, 'r' means learned from (*, *)
entries, 'w' means learned from (*, G) entries.