ICSI Netalyzr

Netalyzr is a java applet developed by ICSI which will let you do a whole bunch of Internet connectivity tests. This can be used to determine the Internet connection status of a machine, including NAT, firewall rules, DNS resolver and much more, which can be very helpful in debugging a PERT case. Netalyzr currently supports the following tests:

* NAT Detection (internal/external IP address)
* DNS based host information (Tor/Spamhaus/SORBS DHUL)
* outbound TCP reachability (FTP, SSH, SMTP, DNS, HTTP, POP3, RPC, NetBIOS^?, IMAP, SNMP, HTTPS, SMB, SMTP/SSL, secure IMAP, authenticated SMTP, IMAP/SSL, POP/SSL, remote SIP server, BitTorrent Server)
* outbound UDP reachability (DNS, MSSQL (port 1434)
* Path MTU discovery
* Network latency measurement
* TCP connection setup latency
* Network background health measurement
* Network bandwidth measurements Upload/Download
* Network buffer measurements
* HTTP proxy detection (address-based/header-based/malformed requests)
* Filetype-based filtering (HTTP cache)
* Javascript-based tests
* domain DNS lookup (restricted/unrestricted)
* Direct EDNS support
* DNS resolver address
* DNS resolver properties
* DNS glue policy
* DNS resolver port randomization
* DNS lookups of popular domains
* DNS external proxy
* DNS results wildcarding
* system clock accuracy
* Browser properties
* Uploaded Data

Here are some screenshots of the applet, so you get a feeling what it looks like:

• Netalyzr Result Summary:
  

• Netalyzr Expanded Summary:
  

• Netalyzr Client Transcript:
  

• Netalyzr Server Transcript:
  

-- ChrisWelti - 15 Jan 2010 - 18 Jan 2010