.PS
SNMP: box at 1,0 "SNMP"
CLI: box at 1,2 "Cisco CLI"

BGP: box at 2,1 "BGP"
ob = boxwid; boxwid = boxwid + 0.2 ; BGPI: box invis at 2,1; boxwid = ob
PIM: box at 5,1 "PIM"
ob = boxwid; boxwid = boxwid + 0.2 ; PIMI: box invis at 5,1; boxwid = ob

arrow from SNMP.e to BGP.w
arrow from SNMP.e to PIM.w
arrow from CLI.e to BGP.w
arrow from CLI.e to PIM.w

"Management" at BGPI.w rjust above
"Interface" at BGPI.w rjust below
"Management" at PIMI.w rjust above
"Interface" at PIMI.w rjust below

arrow from 0,0 to SNMP.w
"External" at SNMP.w rjust above
"Interface" at SNMP.w rjust below

arrow from 0,2 to CLI.w
"External" at CLI.w rjust above
"Interface" at CLI.w rjust below

.PE