google: public telnet server list
for example:
telnet nethack.alt.org
ssh nethack@alt.org
用于在公网环境下测试的Telnet/SSH服务器,布布扣,bubuko.com
用于在公网环境下测试的Telnet/SSH服务器
原文:http://www.cnblogs.com/darkmatter/p/3606824.html