ifMainEncapType 1.3.6.1.4.1.207.1.4.166.27.1.4.1.6

The encapsulation type to be used over the interface. For Ethernet interfaces, the default encapsulation type is ethernetV2(8). The other possible encapsulation is llcSnap(6). If other(1) is specified then an automatic encapsulation type learning method is used in ARP for determining the encapsulation for unicast destinations while the multicast and broadcast destinations use ethernetV2(8). For PPP and MLPPP interfaces, the encapsulation type can only be other(1) and this is the default value. For FR VCs, the value can be nlpid(2) (for carrying protocols which have NLPID) or nlpidSnap(3) (for other protocols). The default is nlpid(2) and the types of protocols supported are inferred from the stack-layering implemented over the interface. For X.25 VCs, the value can be nlpid(2) or nlpidSnap(3) (where the VC can carry multiplexed protocol traffic with each data packet containing the NLPID or SNAP header) or cudNlpid(4) or cudNlpidSnap(5) (where the CUD specifies the NLPID of the protocol or SNAP and the data packets do not contain these headers - for dedicated VCs). The default is cudNlpid(4). For ATM VCs, the default is llcSnap(6) but the vcMultiplexed(7) encapsulation is also supported. This object is not applicable to other interfaces.