When sendmail scans the network hardware to find other names for the local host, it uses only those names that are new. Each new name was printed by the -d0.4 debugging switch described earlier. To see every name that sendmail finds, new and old alike, use the -d0.20 debugging switch:

128.32.201.55                                           already found 
127.0.0.1                                               found new 
        a.k.a.: [127.0.0.1]