Network connectivity determination

A computer readable medium comprising computer executable instructions for determining network connectivity, the computer executable instructions comprising instructions for:

• determining whether a request is for web connectivity or IP connectivity;
• if the request is for IP connectivity:
• executing network profiling to determine Hfar where Hfar is the number of hops to the edge of an ISP network;
• executing a passive analyzer that reviews incoming packets to determine network connectivity;
• executing triggered probing of a network to determine network connectivity;
• and
• executing direct probing of a network to determine network connectivity;
• if the request is for web connectivity:
• determining if a web proxy is present in the network;
• if a web proxy is not present in the network:
• executing network profiling to determine Hfar where Hfar is the number of hops to the edge of an ISP network;
• executing a passive analyzer that reviews incoming packets to determine network connectivity;
• executing triggered probing of a network to determine network connectivity;
• and
• executing direct probing of a network to determine network connectivity;
• if a web proxy is present in the network:
• executing a passive analyzer that reviews incoming packets to determine network connectivity;
• executing triggered probing of a network to determine network connectivity;
• executing direct probing of a network to determine network connectivity;
• and wherein executing web proxy detection further comprises:
• storing a list of a plurality of seed URLs hosted on local sites along with the IP addresses of the hosts;
• performing HTTP GETs for at least two seed URLs;
• determining whether all the HTTP GETs responses match the expected content;
• if the determination of whether all the HTTP GETs responses match the expected content is yes:
• checking for the IP addresses for two responses;
• checking the TTLs for the two responses;
• if the IP addresses and TTLs are as expected, determining that proxy servers are present;
• performing name resolutions for three names;
• determining whether any name successfully resolves but the results are different from the expected result;
• if the determination is yes:
• detecting the presence of DNS spoofing;
• determining that web connectivity is not be present;
• invoking the passive analyzer;
• if the determination of whether all the HTTP GETs responses match the expected content is no:
• determining that a web proxy is present;
• checking IP addresses of responses;
• checking TTLs of responses;
• if addresses are the same for all responses, calculate hop count to proxy server;
• and
• if IP addresses are different than expected website addresses, determine the proxy server IP address.

A computer system comprising a processor for executing computer readable instructions, a memory for storing computer readable instructions and an input-output circuit, the memory storing computer executable instructions comprising steps for:

• determining whether a request is for web connectivity or IP connectivity;
• if the request is for IP connectivity:
• executing network profiling to determine Hfar where Hfar is the number of hops to the edge of an ISP network;
• executing a passive analyzer that reviews incoming packets to determine network connectivity;
• executing triggered probing of a network to determine network connectivity;
• and
• executing direct probing of a network to determine network connectivity;
• if the request is for web connectivity:
• determining if a web proxy is present in the network;
• if a web proxy is not present in the network:
• executing network profiling to determine Hfar where Hfar is the number of hops to the edge of an ISP network;
• executing a passive analyzer that reviews incoming packets to determine network connectivity;
• executing triggered probing of a network to determine network connectivity;
• and
• executing direct probing of a network to determine network connectivity;
• if a web proxy is present in the network:
• executing a passive analyzer that reviews incoming packets to determine network connectivity;
• executing triggered probing of a network to determine network connectivity;
• executing direct probing of a network to determine network connectivity;
• and wherein executing web proxy detection further comprises:
• storing a list of multiple seed URLs hosted on local sites along with the IP addresses of the hosts;
• performing HTTP GETs for a plurality of seed URLs;
• determining whether all the HTTP GETs responses match the expected content;
• if the determination of whether all the HTTP GETs responses match the expected content is yes:
• checking for the IP addresses for two responses;
• checking the TTLs for the two responses;
• performing name resolutions for a plurality of names;
• determining whether any name successfully resolves but the results are different from the expected result;
• if the determination is yes:
• detecting the presence of DNS spoofing;
• determining that web connectivity is not be present;
• invoking the passive analyzer;
• if the determination of whether all the HTTP GETs responses match the expected content is no:
• determining that a web proxy is present;
• checking IP addresses of responses;
• checking TTLs of responses;
• if addresses are the same for all responses, calculate hop count to proxy server;
• and
• if IP addresses are different than expected website addresses, determine the proxy server IP address;
• executing a passive analyzer of network connectivity comprises:
• if the network state is at a no connectivity state:
• moving to internet connectivity state if:
• received I-packet where and I packet comprises packets that arrive from an IPv4 source beyond Hfar;
• or
• received packet from an IPv6 source outside the IPv6 site;
• moving to local connectivity state if:
• received L-packet where an L Packet comprises packets that arrive from an IPv4 source outside the IPv4 subnet but before Hfar;
• or
• received packet from an IPv6 source outside the IPv6 subnet but within the IPv6 site;
• moving to subnet connectivity state if:
• received S packet where an S Packet comprises packets that arrive from a source with the same subnet prefix;
• or
• successfully received address resolution protocol (“ARP”) response from the default gateway;
• and
• staying in no connectivity state if:
• media disconnect or SendARP failed where SendARP sends an ARP request to obtain the physical address that corresponds to the specified destination IP address.
• if at a subnet connectivity state:
• moving to no connectivity state if:
• no received S packet for 30 seconds and SendARP failed;
• or
• a media disconnect;
• moving to local connectivity state if received L-packet;
• moving to internet connectivity state if received I packet;
• staying in subnet connectivity state if:
• received S packet;
• or
• SendARP success.
• if at a local connectivity state;
• moving to subnet connectivity state if no received L packet for 30 seconds;
• moving to internet connectivity state if received I packet;
• moving to no connectivity state if media disconnect;
• and
• staying in local connectivity state if received L packet;
• and
• if at an internet connectivity state:
• moving to local connectivity state if no received I packet for 30 seconds;
• moving to no connectivity state if media disconnects;
• and
• staying in internet connectivity state if received I packet.