R2#sh run int fastEthernet 0/1
Building configuration...

Current configuration : 225 bytes
!
interface FastEthernet0/1
 ip address 200.1.1.2 255.255.255.0
 no ip proxy-arp
 ip irdp
 ip irdp maxadvertinterval 10
 ip irdp minadvertinterval 10
 ip irdp holdtime 30
 ip irdp preference 100
 duplex auto
 speed auto
end

R2#sh run int bvi 1
Building configuration...

Current configuration : 168 bytes
!
interface BVI1
 ip address 17.57.100.99 255.255.255.0
 no ip proxy-arp
 ip irdp
 ip irdp maxadvertinterval 10
 ip irdp minadvertinterval 10
 ip irdp holdtime 30
end

R2#
RACK1AS>4
[Resuming connection 4 to r4 ... ]

R4#sh run | i ip gdp
ip gdp irdp       <----------------- on S5 and R7 as well