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:

– Main.ChrisWelti - 15 Jan 2010 - 18 Jan 2010