On 17/05/15 03:23, Leon Fauster wrote: > Am 15.05.2015 um 18:17 schrieb Gordon Messmer <gordon.messmer at gmail.com>: >> On 05/15/2015 09:02 AM, Leon Fauster wrote: >>> So, the destination is not responding with SYN,ACK when the connection passes >>> our router. But as I said it is reachable from my home, and this is confusing. >>> >>> In such situations, I use HPING in the following manner: hping3 -n -T -S -p 443 yy.yy.yy.yy Breakdown: -n - do not do DNS resolution -T - traceroute mode -S - send SYN packet (you should see flags=SA in the output for a reachable machine) -p - the destination port - 443 in this case You can a -t ## to start off with a larger tty than the default 0. Cheers, ak.