Why can't ping

[EdwardKing]

I configure ed0 when I install FreeBSD7.0,like follows:
Host:test.example.com 
Domain:test.com 
IPv4 GateWay: 172.18.0.1 
Name server: 172.18.0.250 
IPv4 Address: 172.18.0.19 
Netmask:255.255.255.0 

Then I Ping itself,like follows: 
#ping 172.18.0.19 

Then result is failure:
ping: sendto: No route to host 

Why? 

I use ifconfig -a to show my ip,like follows:
 
le0: flags=8843 <UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500 
options=8 <VLAN_MTU> 
either 00:0d:18:23:32:7a 
inet6 fe80::20c:29ff:fe76:365a%le0 prefixlen 64 scopeid 0x1 
inet 0.0.0.0 netmask 0xff000000 broadcast 255.255.255.255 
media: Ethernet autoselect 
status: active 
plip0:flags=108810 <POINTOPOINT,SIMPLEX,MULTICAST,NEEDSGIANT> metric 1500 
lo0:flags=8049 <UP,LOOPBACK,RUNNING,MULTICAST> metric 0 mtu 16384 
inet6::1 prefixlen 128 
inet6 fe80::1%lo0 prefixlen 64 scopeid 0x3 
inet 127.0.0.1 netmask 0xff000000 

Where is my following configure information, I can't find them!
Host:test.example.com 
Domain:test.com 
IPv4 GateWay: 172.18.0.1 
Name server: 172.18.0.250 
IPv4 Address: 172.18.0.19 
Netmask:255.255.255.0 

What raise to lost my configure information? How to configure my ip and how to ping successly?

I am a newer to BSDUnix,please give me detail steps.

Thanks in advance!
Best regards,
Edward


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