No, ma ho provato con un po' di diagnostica, e questo è il risultato...
Summary of Noteworthy Events + –
Major Abnormalities –
Your DNS resolver returns IP addresses for names that do not exist
Minor Aberrations –
Certain TCP protocols are blocked in outbound traffic
The measured packet loss was somewhat high
The measured time to set up a TCP connection was somewhat high
The network measured bursts of packet loss
Not all DNS types were correctly processed
Your computer's clock is slightly slow
Address-based Tests + –
NAT detection (?): NAT Detected +
Local Network Interfaces (?): OK +
DNS-based host information (?): OK +
NAT support for Universal Plug and Play (UPnP) (?): Not found +
Reachability Tests + –
TCP connectivity (?): Note –
Direct TCP access to remote FTP servers (port 21) is allowed.
Direct TCP access to remote SSH servers (port 22) is allowed.
Direct TCP access to remote SMTP servers (port 25) is allowed.
Direct TCP access to remote DNS servers (port 53) is allowed.
Direct TCP access to remote HTTP servers (port 80) is allowed.
Direct TCP access to remote POP3 servers (port 110) is allowed.
Direct TCP access to remote RPC servers (port 135) is blocked.
This is probably for security reasons, as this protocol is generally not designed for use outside the local network.
Direct TCP access to remote NetBIOS servers (port 139) is blocked.
This is probably for security reasons, as this protocol is generally not designed for use outside the local network.
Direct TCP access to remote IMAP servers (port 143) is allowed.
Direct TCP access to remote SNMP servers (port 161) is allowed.
Direct TCP access to remote HTTPS servers (port 443) is allowed.
Direct TCP access to remote SMB servers (port 445) is blocked.
This is probably for security reasons, as this protocol is generally not designed for use outside the local network.
Direct TCP access to remote SMTP/SSL servers (port 465) is allowed.
Direct TCP access to remote secure IMAP servers (port 585) is allowed.
Direct TCP access to remote authenticated SMTP servers (port 587) is allowed.
Direct TCP access to remote IMAP/SSL servers (port 993) is allowed.
Direct TCP access to remote POP/SSL servers (port 995) is allowed.
Direct TCP access to remote OpenVPN servers (port 1194) is allowed.
Direct TCP access to remote PPTP Control servers (port 1723) is allowed.
Direct TCP access to remote SIP servers (port 5060) is allowed.
Direct TCP access to remote BitTorrent servers (port 6881) is allowed.
Direct TCP access to remote TOR servers (port 9001) is allowed.
UDP connectivity (?): OK +
Traceroute (?): OK +
Path MTU (?): OK +
Network Access Link Properties + –
Network latency measurements (?): Latency: 220ms Loss: 15.0% –
The round-trip time (RTT) between your computer and our server is 220 msec, which is good.
We recorded a packet loss of 15%. This loss is very significant and will lead to serious performance problems. It could be due either to very high load on our servers due to a large number of visitors, or problems in your network. Of the packet loss, at least 0.5% of the packets appear to have been lost on the path from your computer to our servers.
TCP connection setup latency (?): 509ms –
The time it takes your computer to set up a TCP connection with our server is 509 msec, which is somewhat high. This may be due to a variety of factors, including distance between your computer and our server, a slow network link, or other network traffic.
Network background health measurement (?): 1 transient outages, longest: 0.8 seconds –
During most of Netalyzr's execution, the applet continuously measures the state of the network in the background, looking for short outages. During testing, the applet observed 1 such outages. The longest outage lasted for 0.8 seconds. This suggests a general problem with the network where connectivity is intermittent. This loss might also cause some of Netalyzr's other tests to produce incorrect results.
Network bandwidth (?): Upload 300 Kbit/sec, Download 2.8 Mbit/sec +
Network buffer measurements (?): Uplink 72 ms, Downlink is good +
HTTP Tests + –
Address-based HTTP proxy detection (?): OK +
Content-based HTTP proxy detection (?): OK +
HTTP proxy detection via malformed requests (?): OK +
Filetype-based filtering (?): OK +
HTTP caching behavior (?): OK +
JavaScript-based tests (?): OK +
DNS Tests + –
Restricted domain DNS lookup (?): OK +
Unrestricted domain DNS lookup (?): OK +
Direct DNS support (?): OK +
Direct EDNS support (?): OK +
DNS resolver address (?): OK +
DNS resolver properties (?): Lookup latency 400ms +
Direct probing of DNS resolvers (?) –
Your system is configured to use 1 DNS resolver(s).
The resolver at 192.168.1.1 (cns-1) could not process the following tested types:
Medium (~1300B) TXT records
Large (~3000B) TXT records
Large (~3000B) TXT records fetched with EDNS0
It does not validate DNSSEC. It wildcards NXDOMAIN errors. Instead of an error it returns the following IP address(es): 212.52.82.27. The resolver reports a number of additional properties. Show them.
DNS glue policy (?): OK +
DNS resolver port randomization (?): OK +
DNS lookups of popular domains (?): OK +
DNS external proxy (?): OK +
DNS results wildcarding (?): Warning –
Your ISP's DNS server returns IP addresses even for domain names which should not resolve. Instead of an error, the DNS server returns an address of 212.52.82.27, which resolves to ar.libero.it. You can inspect the resulting HTML content here.
There are several possible explanations for this behavior. The most likely cause is that the ISP is attempting to profit from customer's typos by presenting advertisements in response to bad requests, but it could also be due to an error or misconfiguration in the DNS server.
The big problem with this behavior is that it can potentially break any network application which relies on DNS properly returning an error when a name does not exist.
The following lists your DNS server's behavior in more detail.
www.{random}.com is mapped to 212.52.82.27.
www.{random}.org is mapped to 212.52.82.27.
fubar.{random}.com is mapped to 212.52.82.27.
www.yahoo.cmo [sic] is mapped to 212.52.82.27.
nxdomain.{random}.netalyzr.icsi.berkeley.edu is mapped to 212.52.82.27.
DNS-level redirection of specific sites (?): OK +
Direct probing of DNS roots (?): +
IPv6 Tests + –
DNS support for IPv6 (?): OK +
IPv4, IPv6, and your web browser (?): No IPv6 support +
IPv6 connectivity (?): No IPv6 support +
Host Properties + –
System clock accuracy (?): Warning –
Your computer's clock is 10 seconds slow.
Browser properties (?): OK +
Uploaded data (?): OK