8.8 Assign an STP role to the CPC You can assign an STP role to the CPC in the CTN. PTS must exist, but BTS and Arbiter roles  are optional. However, it is a good idea to assign BTS and Arbiter based on your CTN  configuration. In this scenario, we assign the Arbiter role to MUSCA, which does not include  an STP role (see Figure 8-60). To assign or modify STP role, complete the following steps: CETUS (z14) Stratum 1 PTS / CTS CTNID=CTLSOMRS HMC 192.168.70.46 Ethernet  Switch router NTP server LEPUS (z13s) Stratum 2 BTS CTNID=CTLSOMRS CF Link MUSCA (z14 ZR1) Stratum 2 CTN ID=CTLSOMRS  Role in CTN None Arbiter HMC 192.168.70.65 NTP server router Figure 8-60 Configuration sample that assigns STP role 8.8.1 HMC operations to assign or modify STP Role 1. Open the Manage System Time task from the HMC that can operate CTN changes to  modify the STP roles. Select  Modify assigned server roles  from the STP ACTIONS list  (see Figure 8-61).  Figure 8-61 Modify server roles Chapter 8. Preparing for Sysplex and configuring Server Time Protocol  193