understanding ip route show command on linux

Question

I have a Windows 7 PC as host.The network details of my Windows PC are as follows.

IP ADDRESS               -   192.168.1.70
DEFAULT GATEWAY          -   192.168.1.254

I have installed Virtual Box on Windows 7 and I have an Ubuntu 12.04 Virtual Machine running on the Virtual Box.

When the networking mode for the Virtual Machine is NAT.

The machine has the IP - 10.0.2.15

I am able to ping from VM to Host PC (Windows 7 - 192.168.1.70)

As expected I am not able to ping from my host PC to the Virtual Machine as the VM is in NAT mode.

The output of ip route show on Ubuntu VM (IP 10.0.2.15) is show below.

sudo ip route show
default via 10.0.2.2 dev eth0  proto static 
10.0.2.0/24 dev eth0  proto kernel  scope link  src 10.0.2.15  metric 1 
169.254.0.0/16 dev eth0  scope link  metric 1000

The output of ifconfig on Ubuntu VM (IP 10.0.2.15) is shown below

eth0      Link encap:Ethernet  HWaddr 08:00:27:da:13:5b  
          inet addr:10.0.2.15  Bcast:10.0.2.255  Mask:255.255.255.0
          inet6 addr: fe80::a00:27ff:feda:135b/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:24658 errors:0 dropped:0 overruns:0 frame:0
          TX packets:12911 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:21780009 (21.7 MB)  TX bytes:935844 (935.8 KB)

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:234 errors:0 dropped:0 overruns:0 frame:0
          TX packets:234 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:39750 (39.7 KB)  TX bytes:39750 (39.7 KB)

My question is

1) What is the meaning of the IP ADDRESS 10.0.2.2 which is shown as the default route ?

2) Why is that not listed in the output of ifconfig.

Thanks & Regards, Karthik.

Solution

1) What is the meaning of the IP ADDRESS 10.0.2.2 which is shown as the default route ?

That is your default gateway - the next hop packets will be routed to if they don't match a more specific route.

2) Why is that not listed in the output of ifconfig.

ifconfig doesn't display routing information.

Comments

[EEAA]

Your question is off topic for Serverfault because it doesn't appear to relate to servers/networking or desktop infrastructure in a professional environment. It may be on topic for Superuser but please search their site for similar questions that may already have the answer you're looking for.

[liv2hak]

So basically what you are saying is that it is the IP address of the Linux Kernel Routing Table.?

[EEAA]

No, there is no such thing as a Linux Kernel Routing Table IP address. 10.0.2.2 is the IP address of your network's gateway.