|
What's new:
The following new features were added to v1.2.2:
1) Fixed
some small bugs. One was LPS only scanning well known TCP Ports up to
1024
when Full TCP Scan was selected.
2) Added Trace Route functionality (some of the ICMP protocol's functions).
So,
what is Trace Route?
Trace Route can used in order to test your network connectivity.
Traceroute
sends a packet of data to the host you specify in the traceroute
query and tracks progress along the way.
Traceroute
tells you the hostnames of the routers which connect our network to
the
destination host. Traceroute
reports the time a packet takes to get through each router
along the path.
ICMP
Protocol Overview
Internet Control Message Protocol (ICMP), documented in RFC 792, is
a required protocol tightly integrated with IP. ICMP messages, delivered
in IP packets, are used for out-of-band messages related to network
operation or mis-operation. Of course, since ICMP uses IP, ICMP packet
delivery is unreliable, so hosts can't count on receiving ICMP packets
for any network problem. Some of ICMP's functions are to:
- Announce
network errors, such as a host or entire portion of the network being
unreachable, due to some type of failure. A TCP or UDP packet directed
at a port number with no receiver attached is also reported via ICMP.
- Announce
network congestion. When a router begins buffering too many packets,
due to an inability to transmit them as fast as they are being received,
it will generate ICMP Source Quench messages. Directed at the sender,
these messages should cause the rate of packet transmission to be
slowed. Of course, generating too many Source Quench messages would
cause even more network congestion, so they are used sparingly.
- Assist
Troubleshooting. ICMP supports an Echo function, which just sends
a packet on a round--trip between two hosts. Ping, a common network
management tool, is based on this feature. Ping will transmit a series
of packets, measuring average round--trip times and computing loss
percentages.
- Announce
Timeouts. If an IP packet's TTL field drops to zero, the router discarding
the packet will often generate an ICMP packet announcing this fact.
TraceRoute is a tool which maps network routes by sending packets
with small TTL values and watching the ICMP timeout announcements.
Bold
items are implemented by the Trace Route function.
More
information on ICMP can be found at http://www.freesoft.org/CIE/Topics/81.htm.
|