Group MAC that the ISIS control plane will use. SPB may use a number of different addresses for SPB Hello and LSP exchange. Section 27.2, 8.13.1.5 and Table 8-13 covers the different choices. The choices are as follows: 01:80:C2:00:00:14 = All Level 1 Intermediate Systems 01:80:C2:00:00:15 = All Level 2 Intermediate Systems 09:00:2B:00:00:05 = All Intermediate Systems. 01:80:C2:00:00:2E = All Provider Bridge Intermediate Systems. 01:80:C2:00:00:2F = All Customer Bridge Intermediate Systems. This object is persistent.