This page lets you test connectivity using Ping or Traceroute, or by sending a TCP or UDP packet to a specific port.
- Target Address can be an IP address or a DNS host name, provided that DNS resolution is correctly configured (System > DNS).
- Source Address can be any (blank), or the IP address of a specific interface.
TCP specific note:
- An OK response (flags=SA) means that the port is open and the server accepted the request.
- A REJECTED response (flags=RA) means that the server is present, but the port is not listening.
- An ICMP response (or no response) typically means that there is no host at the specified address, or that a firewall may have blocked the packet.
UDP specific note:
- No response may or may not indicate a problem; even when the port is reachable and open, the target host is unlikely to respond to a packet that most likely doesn't contain any valid protocol data.
- An "ICMP Port Unreachable" response means that the target host is reachable, but the port is closed (other ICMP messages may also be received, e.g. from routers on the path).
Note: You will only be able to ping or traceroute through a VPN tunnel if the source address is within the "Local Network" subnet as configured for that particular tunnel.