Is there a difference between the contents of the routing table and the routing cache immediately after the ICMP route redirect message?

Question

What will be an ideal response?

Answer 1

```
[root@PC2 root]# ping -c 5 10.0.3.10
PING 10.0.3.10 (10.0.3.10) 56(84) bytes of data.
From 10.0.2.1: icmp_seq=1 Redirect Network(New nexthop: 10.0.2.2)
From 10.0.2.1: icmp_seq=2 Redirect Network(New nexthop: 10.0.2.2)
--- 10.0.3.10 ping statistics ---
5 packets transmitted, 0 received, 100% packet loss, time 4056ms
```
There is no change to the static routing table before and after the ICMP Redirect message. However, there are changes to the routing cache of PC2, as shown below:
Before
```
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
10.0.2.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo
0.0.0.0 10.0.2.1 0.0.0.0 UG 0 0 0 eth0
```
After :
```
[root@PC2 root]# netstat -rn
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
10.0.2.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo
0.0.0.0 10.0.2.1 0.0.0.0 UG 0 0 0 eth0
```
Before
```
: [root@PC2 root]# route -C
Kernel IP routing cache
Source Destination Gateway Flags Metric Ref Use Iface
PC2 PC2 PC2 l 0 0 133 lo
PC2 PC2 PC2 l 0 0 63 lo
PC2 PC2 PC2 l 0 0 459 lo
```
After :
```
[root@PC2 root]# route -C
Kernel IP routing cache
Source Destination Gateway Flags Metric Ref Use Iface
10.0.2.10 10.0.3.10 10.0.2.2 0 0 1 eth0
PC2 PC2 PC2 l 0 0 215 lo
10.0.2.10 10.0.3.10 10.0.2.2 0 0 4 eth0
PC2 PC2 PC2 l 0 0 103 lo
PC2 PC2 PC2 l 0 0 743 lo
10.0.2.1 10.0.2.10 10.0.2.10 il 0 0 1 lo
```