Include the routing tables of the Linux PCs before the topology was changed (Step 2) and after Router4 has been added and the routing tables have been updated (Step 5). Discuss the time it took to update the routing tables.

What will be an ideal response?

After Router4 is added, routing path from PC2 to PC4 and from PC4 to PC1 and PC2 would be changed to use Router4 as an intermediate router in each routing path. The bold typeset below represents the changed routing path by indicating the associated gateway to reach each destination network.
The path from PC1 to PC4 was PC1->Router1->Router2->Router3->PC4 and new path is now
PC1->Router1->Router4->PC4.
? Before adding Router4:
Routing Table on PC2
```
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
10.0.4.0 10.0.2.2 255.255.255.0 UG 0 0 0 eth0
10.0.1.0 10.0.2.1 255.255.255.0 UG 0 0 0 eth0
10.0.2.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
10.0.3.0 10.0.2.2 255.255.255.0 UG 0 0 0 eth0
127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo
```
Routing Table on PC4
```
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
10.0.4.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
10.0.1.0 10.0.4.3 255.255.255.0 UG 0 0 0 eth0
10.0.2.0 10.0.4.3 255.255.255.0 UG 0 0 0 eth0
10.0.3.0 10.0.4.3 255.255.255.0 UG 0 0 0 eth0
127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo
```
? After adding Router4:
Routing Table on PC1
```
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
10.0.4.0 10.0.1.1 255.255.255.0 UG 0 0 0 eth0
10.0.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
10.0.2.0 10.0.1.1 255.255.255.0 UG 0 0 0 eth0
10.0.3.0 10.0.1.1 255.255.255.0 UG 0 0 0 eth0
127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo
```
Routing Table on PC2
```
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
10.0.4.0 10.0.2.4 255.255.255.0 UG 0 0 0 eth0
10.0.1.0 10.0.2.1 255.255.255.0 UG 0 0 0 eth0
10.0.2.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
10.0.3.0 10.0.2.2 255.255.255.0 UG 0 0 0 eth0
127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo
```
Routing Table on PC3
```
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
10.0.4.0 10.0.3.3 255.255.255.0 UG 0 0 0 eth0
10.0.1.0 10.0.3.2 255.255.255.0 UG 0 0 0 eth0
10.0.2.0 10.0.3.2 255.255.255.0 UG 0 0 0 eth0
10.0.3.0 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
```
Routing Table on PC4

```
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
10.0.4.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
10.0.1.0 10.0.4.4 255.255.255.0 UG 0 0 0 eth0
10.0.2.0 10.0.4.4 255.255.255.0 UG 0 0 0 eth0
10.0.3.0 10.0.4.3 255.255.255.0 UG 0 0 0 eth0
127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo
```
Routing Tables on Router1

```
Router1>
Router1>show ip route
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate default
U - per-user static route, o - ODR
Gateway of last resort is not set
10.0.0.0/24 is subnetted, 4 subnets
C 10.0.2.0 is directly connected, Ethernet0/1
R 10.0.3.0 [120/1] via 10.0.2.2, 00:00:26, Ethernet0/1
C 10.0.1.0 is directly connected, Ethernet0/0
R 10.0.4.0 [120/1] via 10.0.2.4, 00:00:10, Ethernet0/1
```
Routing Tables on Router2
```
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate default
U - per-user static route, o - ODR
Gateway of last resort is not set
10.0.0.0/24 is subnetted, 4 subnets
C 10.0.2.0 is directly connected, Ethernet0/1
C 10.0.3.0 is directly connected, Ethernet0/0
R 10.0.1.0 [120/1] via 10.0.2.1, 00:00:08, Ethernet0/1
R 10.0.4.0 [120/1] via 10.0.3.3, 00:00:10, Ethernet0/0
[120/1] via 10.0.2.4, 00:00:03, Ethernet0/1
```
Routing Tables on Router3
```
Router3#show ip route
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate default
U - per-user static route, o - ODR
Gateway of last resort is not set
10.0.0.0/24 is subnetted, 4 subnets
R 10.0.2.0 [120/1] via 10.0.3.2, 00:00:09, Ethernet0
[120/1] via 10.0.4.4, 00:00:16, Ethernet1
C 10.0.3.0 is directly connected, Ethernet0
R 10.0.1.0 [120/2] via 10.0.3.2, 00:00:10, Ethernet0
[120/2] via 10.0.4.4, 00:00:16, Ethernet1
C 10.0.4.0 is directly connected, Ethernet1
```
Routing Tables on Router4
```
Router4#show ip route
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate default
U - per-user static route, o - ODR
Gateway of last resort is not set
10.0.0.0/24 is subnetted, 4 subnets
C 10.0.2.0 is directly connected, Ethernet1
R 10.0.3.0 [120/1] via 10.0.2.2, 00:00:01, Ethernet1
[120/1] via 10.0.4.3, 00:00:07, Ethernet0
R 10.0.1.0 [120/1] via 10.0.2.1, 00:00:07, Ethernet1
C 10.0.4.0 is directly connected, Ethernet0
```
The routing table update time can be retrieved by checking the routing table of each routers or by analyzing the captured packet for RIP version2.