Useful Cisco Links:

Dans Courses: Beaucoup videos covering Cisco, Microsoft, Linux, Security 

Practical Networking articles and animated graphics 

GE Geek Tech Toolkit 

Free online TCP/IP reference guide 

Free E-book CCNA-Complete-Guide-2nd-Edition 

Free E-book CCNP Routing

Cisco Learning Systems

Hyperterminal Private Edition (scrollback bug fixed)

Tera Term v 4.82 

WireShark v 1.10.7 (32-bit) 

puTTY v 0.63 (stable) 

Sam Spade super trace route + more graphical utility 

Tftpd32 TFTP server

Mark's "White Papers", including the NSF-funded security lab

IBM red book on TCP/IP