Hello, Does anyone know a utility to show you at what point (perhaps a router hop) a port is being blocked? A customer of ours has said they have opened their firewall to allow port 11000, I cant see any drops on our router/firewall, but would like to trace somehow at which point or router/firewall is dropping the packet. We cannot get to their network on this port. Thanks
port-being blocked
Jun 28, 2005
2 Replies
Hi,
Are you able to do a port scan on the specific IP address to see if the port is really open (possibly the ISP has blocked the port)?
If its a TCP port there is a Unix based tcp traceroute tool called "tcptraceroute" available at
formatting link
can specify destination ports.
I dont know of any Windows tools that do this, anybody else know?
Hope this helps,
Rob
cc> Hello,
Unless they've configured "no ip unreachable", the router should send an ICMP Unreachable -- Administratively Prohibited when it drops a packet due to a filter.
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