Enterasys N Standalone (NSA) Series Configuration Manual page 973

Table 12-7 provides an explanation of the command output.
Table 12-7 show ip pim rp Output Details
Output
Group(s)
RP
Priority
Expiry
Uptime
What It Displays...
Address of the multicast group(s) about which to display RP
data.
Address of the RP for that group.
RP priority value.
Period (in hours:minutes:seconds) in which the next
bootstrap message is due from this BSR.
Interval that this router has been up in
hours:minutes:seconds.
Matrix NSA Series Configuration Guide
IP Configuration Command Set
Configuring PIM
12-61