when i use if config:
linux:~ # ifconfig
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:1729 errors:0 dropped:0 overruns:0 frame:0
TX packets:1729 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:147516 (144.0 Kb) TX bytes:147516 (144.0 Kb)

ra0 Link encap:Ethernet HWaddr 00:02:44:93:24:4F
inet addr: 192.168.0.68 Bcast:192.168.0.255 Mask:255.255.255.0
inet6 addr: fe80::202:44ff:fe93:244f/64 Scope:Link
UP BROADCAST NOTRAILERS RUNNING MULTICAST MTU:1500 Metric:1
RX packets:81459 errors:0 dropped:0 overruns:0 frame:0
TX packets:64563 errors:6 dropped:6 overruns:0 carrier:0
collisions:20813 txqueuelen:1000
RX bytes:96893951 (92.4 Mb) TX bytes:8807000 (8.3 Mb)
Interrupt:11
It says that my IP on the LAN is 192.168.0.68
Now when i want to ping the hosts on my LAN:
linux:~> nmap -sP 192.168.0.0/24

Starting Nmap 3.95 ( http://www.insecure.org/nmap/ ) at 2006-02-24 08:03 GST
Host 192.168.0.1 appears to be up.
Host 192.168.0.64 appears to be up.
Host 192.168.0.66 appears to be up.
Host 192.168.0.68 appears to be up.
Nmap finished: 256 IP addresses (4 hosts up) scanned in 3.687 seconds
And as you can see 192.168.0.68 is up on the LAN , my question is how can it happen? did i ping myself? how am i mentioned as a live host, and am I really 192.168.0.68?

--thanks