Try mtr, use the -T or --tcp, of -u for UDP. See that that does for you.
On Sun, Nov 19, 2017 at 9:53 PM, david <dafr+p...@dafr.us> wrote: > On 11/18/2017 03:47 PM, Rich Shepard wrote: > >> With the mail/phone issues I've had recently I want to check that I'm >> doing things correctly. Two instances of not reaching web pages. >> >> I can load (and ping) www.opendkim.org, but cannot load (or ping) >> lists.opendkim.org. This means their mail list page is off-line. Yes? >> > > No, not necessarily. > > Yesterday and today I try to access www.verizonwireless.com but the >> page >> won't load. Neither can I ping that server. This means that their web site >> is down. Yes? >> > > Again, not necessarily. > > More and more IT / Security groups are going to dropping the ICMP (ping) > packets for "security" reasons, and this affects several tools that have > long been used by the layperson and professional alike. > > When the firewall receives an ICMP packet, ping and traceroute both will > show failure and/or lack of "up: state. If the attacker knows the device is > there by DNS resolution or IP address, they have a known target, and the > dropping of packets (IMO) is just obscuring things a little bit. > > Other tools that you can try are telnet to the port for the service in > question, nmap to check for all open ports (potential for looking like an > attacker), and netcat (nc) to test for specific, or scan for all open, > ports. > > A deeper way to search if things are connecting at all is the use of > netstat, Wireshark, or tcpdump in some cases. > > Network connectivity is going to likely become more problematic, and our > means of testing things will likely become more restricted as time passes. > Just my guess, but it's a trend I have been noticing. > > dafr > > _______________________________________________ > PLUG mailing list > PLUG@pdxlinux.org > http://lists.pdxlinux.org/mailman/listinfo/plug > -- Chuck Hast -- KP4DJT -- I can do all things through Christ which strengtheneth me. Ph 4:13 KJV Todo lo puedo en Cristo que me fortalece. Fil 4:13 RVR1960 _______________________________________________ PLUG mailing list PLUG@pdxlinux.org http://lists.pdxlinux.org/mailman/listinfo/plug
