Ip route Profile Troubleshooting

[Alfredo Bosca Bataller]

I am monitoring my network topology with the ip route profile command to see the changes in the routing table. I need that anybody help me to explin the output.

R1#show running-config | section ospf

ip ospf priority 10

router ospf 1

router-id 1.1.1.1

log-adjacency-changes

summary-address 172.16.0.0 255.255.252.0

redistribute static

network 172.30.0.0 0.0.0.255 area 0

R1#show ip route

Gateway of last resort is not set

     172.16.0.0/24 is subnetted, 4 subnets

S       172.16.0.0 is directly connected, Null0

S       172.16.1.0 is directly connected, Null0

S       172.16.2.0 is directly connected, Null0

S       172.16.3.0 is directly connected, Null0

     172.30.0.0/24 is subnetted, 3 subnets

O IA    172.30.20.0 [110/210] via 172.30.0.3, 00:00:27, FastEthernet0/0

C       172.30.0.0 is directly connected, FastEthernet0/0

O IA    172.30.10.0 [110/210] via 172.30.0.2, 00:00:27, FastEthernet0/0

     10.0.0.0/22 is subnetted, 2 subnets

O IA    10.10.0.0 [110/211] via 172.30.0.2, 00:00:28, FastEthernet0/0

O IA    10.20.0.0 [110/211] via 172.30.0.3, 00:00:28, FastEthernet0/0

R1#show ip route profile

IP routing table change statistics:

Frequency of changes in a 5 second sampling interval

-------------------------------------------------------------

Change/   Fwd-path  Prefix   Nexthop  Pathcount  Prefix

interval  change    add      change   change     refresh

-------------------------------------------------------------

0         6         6        6        6          5

1         0         0        0        0          0

2         0         0        0        0          0

3         0         0        0        0          0

4         0         0        0        0          1

5         0         0        0        0          0

10        0         0        0        0          0

15        0         0        0        0          0

The routing table take 6 * 5 = 30 sec without changes. But, Why the prefix refresh value is one less??

After remove the command "network 172.30.0.0 0.0.0.255 area 0" and add again. The output is the next:

R1#show ip route profile

IP routing table change statistics:

Frequency of changes in a 5 second sampling interval

-------------------------------------------------------------

Change/   Fwd-path  Prefix   Nexthop  Pathcount  Prefix

interval  change    add      change   change     refresh

-------------------------------------------------------------

0         48        48       49       49         45

1         0         0        0        0          0

2         0         0        0        0          0

3         0         0        0        0          0

4          1         1        0        0          4

5         0         0        0        0          0

10        0         0        0        0          0

15        0         0        0        0          0

20        0         0        0        0          0

25        0         0        0        0          0

Because 4 changes???

Thanks,

[ramon.yu.jr]

Aside from the row 0 showing you no changes if all below it are zero, it also means how long the ip profile has been enabled.  The reason why prefix refresh value is one less is because there were 4 changes within an interval for one prefix as you can see on row 4 where there is a value of 1 under prefex refresh.  You add that to 5 will equate to that with no change.  This is the same when you look at the table again after you add the 172.30.0.0 subnet.

It's not actually 4 changes after you added the subnet back but 3.  You see it 4 because it had a value of 1 previously.  If you look at the routing table, it will add the subnets 172.30.0.0, 172.30.10.0 and 172.30.20.0.

Here is a definition of the fields for your reference:

• Forward-Path Change - This statistic is the number of changes in the forwarding path, which is the accumulation of prefix-add, next-hop change, and pathcount change statistics.
  
• Prefix-Add - A new prefix was added to the routing table.
  
• Next-Hop Change - A prefix is not added or removed, but the next hop changes. This statistic is only seen with recursive routes that are installed in the routing table.
  
• Pathcount Change - The number of paths in the routing table has changed. This statistic is the result of an increase in the number of paths for an Interior Gateway Protocol (IGP) prefix in the routing table.
  
• Prefix Refresh - Standard routing table maintenance; the forwarding behavior is not changed.