Eigrp another setup

 A new set up of EIGRP.R1 is connected to 10.2.0.0/24 which needs to be summarized on int f0/0.

i wanted to check Null0 Interface.

eigrp offset

R1
=====
show ip proto --->output


Routing Protocol is "eigrp 10"
  Outgoing update filter list for all interfaces is not set
  Incoming update filter list for all interfaces is not set
  Default networks flagged in outgoing updates
  Default networks accepted from incoming updates
  EIGRP metric weight K1=1, K2=0, K3=1, K4=0, K5=0
  EIGRP maximum hopcount 100
  EIGRP maximum metric variance 1
  Redistributing: connected, eigrp 10
  EIGRP NSF-aware route hold timer is 240s
  Automatic network summarization is not in effect
  Maximum path: 4
  Routing for Networks:
    10.10.10.0/24
    10.10.20.0/24
  Routing Information Sources:
    Gateway         Distance      Last Update
    10.10.10.2            90      00:03:00
    10.10.20.2            90      00:03:00
  Distance: internal 90 external 170


Show IP route output



Gateway of last resort is not set

     1.0.0.0/24 is subnetted, 1 subnets
C       1.1.1.0 is directly connected, Loopback1
     10.0.0.0/24 is subnetted, 2 subnets
C       10.10.10.0 is directly connected, Serial1/0
C       10.10.20.0 is directly connected, Serial1/1
D    192.168.1.0/24 [90/2172416] via 10.10.20.2, 00:13:15, Serial1/1
                    [90/2172416] via 10.10.10.2, 00:13:15, Serial1/0



after offset

successor and feasible successor

I know that only successor routes appear in the routing table, but how can I tell the difference between successor and feasible successor?

R1# show ip eigrp topology
IP-EIGRP Topology Table for AS(1)/ID(172.31.16.1)

Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,
r - reply Status, s - sia Status
P 172.31.151.0/24, 1 successors, FD is 768
via Connected, Loopback1
P 172.31.211.0/24, 1 successors, FD is 1024
via 172.31.11.201 (1024/76, FastEthernet0/0
P 172.31.24.0/30, 1 successors, FD is 768
via 172.31.11.2 (768/512), FastEthernet0/0
via 172.31.14.2 (1024/512), Serial0/0.4


======================================


P 172.31.24.0/30, 1 successors, FD is 768
via 172.31.11.2 (FD768/AD512), FastEthernet0/0
via 172.31.14.2 (FD1024/AD512), Serial0/0.4