mail lists, blogs, news sites, forums, etc
NANOG mail list
cisco nsp mail list
IPv6 nsp mail list
Group Study CCIE Lab archive
Ineternetwork Expert forums
Cisco network professionals forum
Blogs @Cisco
The Internet Protocol Journal
NetCraftsmen Blogs
Terry's Blog (CCIE #1026)
Internetwork Expert Blog
Ivan Pepelnjak's Blog
Packet Life
Network World's Cisco related blogs
SMBlog -- Steve Bellovin's Pseudo-Random Blog
bugtrack, incidents, etc mail lists
Network World

podcasts, webcasts, youtube channels, etc
SANS institute Webcasts
Packet Pushers Podcast
Cisco Live Virtual
Cisco's Youtube Channel
Cisco's Service Provider Youtube Channel
Cisco TAC Security Podcasts
Inernetwork Expert's Youtube Channel
Bright Talk Information Security Channel

operational resources/tools
team cymru bogon list
route-views.oregon-ix.net
internet storm center
CERT
Forum for Incident Response and Security Teams
internet traffic report
RFC search
NSI whois
ARIN IP & AS whois (north america)
RIPE IP & AS whois (europe)
APNIC IP & AS whois (asia pacific)
NSA Security Configuration Guides
NIST Computer Security Division

standards bodies/professional organizations
IETF : internet engineering taskforce
IEEE : Institute of Electrical and Electronics Engineers
NANOG : The North American Network Operators' Group
IANA : Internet Assigned Numbers Authority
ARIN : American Registry for Internet Numbers
ISC2
Usenix
The SANS Institute
IPv6 group
IPv6 forum
the MPLS / Frame Relay / ATM forum


utilities & software
wireshark (formerly ethereal)
nmap
solarwinds tftp / subnetc calculator
snort
dsniff
mrtg
cricket
flowscan
netstumbler
rancid
big brother
net-snmp
fedora linux