sam sneed wrote: > There is no simple tool to do this Osama. Try connecting to 1720 on some > servers on other networks. While you do this do use a sniffer. You should > get a connectrion refused (RST) from the server. Verify this with packets > captured by sniffer. If you simply see syn packets going out and no > connection refused message, that means a firewall is dropping them silently. > Some FW's will send the reject message themselves Osama. You will also be > able to see this in the packet dump. These problems take a lot of trial and > error and cooperation of your ISP to resolve but are not impossible to > troubleshoot. > > > ""Osama Kamal"" wrote in message > [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > >>I am having a problem with a blocked port somewhere on the internet down > > to > >>my router, my ISP is denying any blocking from their side, is there is any >>way to know where exactly the port is blocked? >> >>Thanks use 'hping' with -T option. it works most unix machine.
following is a test output. tcp/514 is filtered at 61.42.0.234. % hping -n -S -p 514 -T xxx.yyy.zzz HPING xxx.yyy.zzz (hme0 a.b.c.d): S set, 40 headers + 0 data bytes hop=1 TTL 0 during transit from ip=211.174.57.2 hop=1 hoprtt=0.9 ms hop=2 TTL 0 during transit from ip=203.248.248.201 hop=2 hoprtt=0.6 ms hop=3 TTL 0 during transit from ip=211.32.118.125 hop=3 hoprtt=0.7 ms hop=4 TTL 0 during transit from ip=211.233.55.65 hop=4 hoprtt=0.7 ms hop=5 TTL 0 during transit from ip=210.92.194.209 hop=5 hoprtt=0.7 ms hop=6 TTL 0 during transit from ip=210.120.61.37 hop=6 hoprtt=1.2 ms hop=7 TTL 0 during transit from ip=210.120.244.34 hop=7 hoprtt=1.5 ms hop=8 TTL 0 during transit from ip=210.120.104.158 hop=8 hoprtt=1.7 ms hop=9 TTL 0 during transit from ip=210.120.104.174 hop=9 hoprtt=1.7 ms ICMP Packet filtered from ip=61.42.0.234 ICMP Packet filtered from ip=61.42.0.234 ICMP Packet filtered from ip=61.42.0.234 ^C --- xxx.yyy.zzz hping statistic --- 35 packets tramitted, 0 packets received, 100% packet loss round-trip min/avg/max = 0.6/1.1/1.7 ms Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=54986&t=53657 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
