before I could ping, now I can't

[Vwaju <lou@manhattanhandyman.com>]

I am building an internet server (primarily to get some experience
with and knowledge of networking).

I installed Debian GNU/Linux 4.9 r3 _Etch_ Official i386 Binary-1
222080218-14:15 (debian-40r3-i386-netinst.iso).

I was able to ping both IP addresses and domain names.  Then I
installed ssh and rebooted, and I couldn't ping *anything*.

jupiter:/home/admin# ping manhattanhandyman.com
ping: unknown host manhattanhandyman.com

jupiter:/home/admin# ping 216.227.214.3
connect:  network is unreachable

I would appreciate any suggestions.

Best Regards,

Vwaju
New York City