Link Name Description Geoff Huston site with many interesting IT-related links, for example BGP Routing Table Analysis Reports, CIDR reports, IPv4, IPv6 reports and others. Robtex Swiss Army Knife Internet Tool — many usefull tools for geathering information about ISP resources. Here you can search for:
  * rbls (example: checks multiple RBL:s. check if your mailserver is listed in any blacklist
  * ipnumber (example: checks ipnumber
  * hostnames (example: checks dns-info for a specific hostname
  * domainnames (example: checks dns-info for a domain
  * whois lookup (example: checks whois-info for a domain
  * c-net (example 192.168.0) checks reverse for a c-net
  * route (example checks a specific route
  * as numbers (example: AS3333 (RIPE-NCC-AS, RIPE Network Coordination Centre))
  * bgp announcements (example: AS3333)
  * as macros (example: as-ams-ix-peers)
  * rfcnumbers (example: rfc2822) 
  ...and so on.

Traceroute and BGP looking glass links sites

Link Name Description Tracoute sites link collection from Thomas Kernen. Collection of russian LGs RUNNET NOC collection