Free icmp echo software for linux

ICMPScan scans the specified address, or addresses, for ICMP responses.

Usage:

icmpscan [ -EPTSNMAIRcvbn ] [ -A address ] [ -f filename ] [ -i interface ] [ -r retries ] [ -t timeout ] target [...]

Options:

-i, --interface
Listen on the specified interface. If unspecified, icmpscan will examine the routing table and select the most appropriate interface for each target address.
-c, --promisc
Put in interface into promiscuous mode. As this option increases the load on the system in general, it should only be used if spoofing of source packets address is enabled with the "-A" option.
-A, --address
Specify the source IP address of generated packets.
-t, --timeout
Specify the timeout, in milli-seconds, before retrying.
-r, --retries
Specify the number of attempts to elicit a particular ICMP response.
-f, --file
Read target list from the specified file.
-E, -P, --echo, --ping
Check of ICMP Echo responses.
-T, -S, --timestamp
Check for ICMP Timestamp responses.
-N, -M, --netmask
Check for ICMP Netmask responses.
-I, --info
Check for ICMP Info responses.
-R, --router
Check for ICMP Router Solicitation responses.
-v, --verbose
Increase the output verbosity.
-B, --debug

Target Specification

The simplest case is listing single hostnames or IP addresses on the command line. If you want to scan a subnet of IP addresses, you can append /mask to the hostname or IP address. mask must be between 0 (scan the whole Internet) and 32 (scan the single host specified). Use /24 to scan a class "C" address and /16 for a class "B". There is also a more powerful notation which lets you specify an IP address using lists/ranges for each element. Thus you can scan the whole class "B" network 192.168.*.* by specifying "192.168.*.*" or "192.168.0-255.0-255" or even "192.168.1-50,51-255.1,2,3,4,5-255". And of course you can use the mask notation: "192.168.0.0/16". These are all equivalent. If you use asterisks ("*"), remember that most shells require you to escape them with back slashes or protect them with quotes.

Examples:

The following example checks the first 16 addresses in the 192.168.1.0/24 netblock for all ICMP responses. The scan speed is increased by lowering the timeout value and setting the number of retries to 1:

> icmpscan -t 500 -r 1 192.168.1.0-16
192.168.1.0: Echo (From 192.168.1.17!)
192.168.1.0: Address Mask [255.255.255.0] (From 192.168.1.17!)
192.168.1.7: Echo
192.168.1.7: Timestamp [0x03ab2db0, 0x02d4c507, 0x02d4c507]
192.168.1.7: Address Mask [255.255.255.0]
192.168.1.8: Echo
192.168.1.8: Address Mask [255.255.255.0]
To display failed probes, increase the output verbosity:

> icmpscan -v 192.168.1.1
192.168.1.1: -- No response to Echo request --
192.168.1.1: -- No response to Timestamp request --
192.168.1.1: -- No response to Netmask request --
192.168.1.1: -- No response to Info request --
192.168.1.1: -- No response to Router Solicitation request --
Individual ICMP types can be checked for by listing their corresponding flags on the command line:

> icmpscan -v --echo --netmask 192.168.1.7
192.168.1.7: Echo
192.168.1.7: Address Mask [255.255.255.0]

Icmpenum sends ICMP traffic to potential targets on a network.
Introduction:
Host enumeration is the act of determining the IP address of potential targets on a network. This can be done in both layer 2 and layer 3. Icmpenum sends ICMP traffic for such enumeration. The ICMP packets supported are: Echo, Timestamp, Information and Netmask. Furthermore, it supports spoofing and promiscuous listening for reply packets. Icmpenum is great for enumerating networks which allow ICMP traffic.
Installation:
1. Install the latest libpcap (libpcap 0.4, ftp://ftp.ee.lbl.gov/libpcap.tar.Z).
2. Install the latest Libnet (http://www.packetfactory.net/libnet/).
3. Compile icmpenum as follows:
gcc `libnet-config --defines` -o icmpenum icmpenum.c -lnet -lpcap
4. Copy icmpenum to your fave directory and (as root) start enumerating.
Usage:
Running icmpenum -h gives you the following screen:
# ./icmpenum -h
USAGE: ./icmpenum [opts] [-c class C] [-d dev] [-i 1-3] [-s src] [-t sec] hosts
opts are h n p r v
-h this help screen
-n no sending of packets
-p promiscuous receive mode
-r receiving packets only (no
-v verbose
-c class C in x.x.x.0 form
-i icmp type to send/receive, types include the following:
1 echo/echo reply (default)
2 timestamp request/reply
3 info request/reply
-d device to grab local IP or sniff from, default is eth0
-s spoofed source address
-t time in seconds to wait for all replies (default 5)
host(s) are target hosts (ignored if using -c)
Examples:
Here are some example uses of icmpenum to enumerate hosts.
Example 1:
[Host1]# icmpenum 192.168.1.1 192.168.1.2
This will use the default of Echo packets to try and determine if
192.168.1.1 and 192.168.1.2 are up and running.
Example 2:
[Host1]# icmpenum -i 2 -v 192.168.100.100 192.168.100.200
This will enumerate the two hosts using Timestamp packets in
verbose mode.
Example 3:
[Host1]# icmpenum -i 3 -s 10.10.10.10 -p -v 192.168.1.1 192.168.1.2
This will enumerate hosts 192.168.1.1 and 192.168.1.2 using
Information packets with a spoofed address of 10.10.10.10, since our real address is 10.10.10.11 we use the -p option to listen for the replies.
Here are some more advanced uses of icmpenum.
Example 4:
Assuming Host1 is 6.6.6.6 and Host2 is 7.7.7.7, and that the network 1.1.1.0 has potential hosts to enumerate, we use the following two entries to enumerate with Information packets:
[Host2]# icmpenum -r -t 30 -i 3 -c 1.1.1.0
[Host1]# icmpenum -s 7.7.7.7 -i 3 -c 1.1.1.0
Host2 starts first in receive mode with a timeout of 30 seconds and starts listening for Information packets from the 1.1.1.0 network. Then Host1 starts sending spoofed packets with Host2 as the source address, sending exactly what Host2 is listening for. It should be noted that this is hardly stealthy, as logs at 1.1.1s site could have 7.7.7.7s address all over them, but the -r function is good for testing.
Example 5:
Assuming Host1 is 6.6.6.6 and Host2 is 7.7.7.7, and that Host2 can sniff traffic between 1.1.1.0 and 2.2.2.0, we use the following entries to enumerate the 1.1.1.0 network:
[Host2]# icmpenum -t 20 -n -p -i 2 -c 1.1.1.0
[Host1]# icmpenum -s 2.2.2.2 -i 2 -c 1.1.1.0
Host2 starts first with a timeout of 20 seconds, makes sure not to send the packets with the -n option, listens promiscuously for Timestamp packets from the 1.1.1.0 network. Host1 sends the exact packets Host2 is listening for with a 2.2.2.2 spoofed source address. Yes, one could simply replace the -n option in Host2s command line with -s 2.2.2.2 and do the same thing from one workstation, but were demonstrating a distributed concept.
Enhancements:
- I have added ICMP MASK (type 17 and 18) requests and replys. Simply use the -i 4 option on the command line, such as; icmpenum -i 4 -c 1.2.3.1 (sends ICMP MASK requests to the Class C range 1.2.3.1/24 and reports any system as.
- Due to the use of some older versions of Libnet and Libpcap. I can see problems for some people compiling this and hence have placed two statically linked versions within the tarball

IPChains is a Perl module to create and manipulate ipchains via Perl.

SYNOPSIS

use IPChains;
$fw = IPChains->new(-option => value, ... ); $fw->append(chain);

This module acts as an interface to the ipchains(8) userspace utility by Paul "Rusty" Russell (http://www.rustcorp.com/linux/ipchains/). It attempts to include all the functionality of the original code with a simplified user interface via Perl. In addition, plans for log parsing facilities, an integrated interface to ipmasqadm, and possibly traffic shaping are slated for up and coming versions.
The new() and attribute() methods support the following options:

Source

Specifies origination address of packet. Appending hostmask to this address using a / is OK, as well as specifying it separately (see SourceMask).

SourceMask

Hostmask for origination address. Can either be in 24 or 255.255.255.0 style.

SourcePort

Specific port or port range (use xxx:xxx to denote range), requires specific protocol specification.

Dest

Specifies destination address of packet. Appending hostmask to this address using a / is OK, as well as specifying it separately (see DestMask)

DestMask

Destination address, (see SourceMask).

DestPort

Destination Port, (see SourcePort).

Prot

Protocol. Can be tcp, udp, icmp, or all. Required for specifying specific port(s).

ICMP

ICMP Name/Code (in place of port when ICMP is specified as protocol).

Here is a small table of some of the most common ICMP packets:

Number Name Required by

0 echo-reply ping
3 destination-unreachable Any TCP/UDP traffic.
5 redirect routing if not running
routing daemon
8 echo-request ping
11 time-exceeded traceroute

Rule

Target. Can be ACCEPT, DENY, REJECT, MASQ, REDIRECT, RETURN, or a user-defined chain. Note: This is case sensitive.

Interface

Specify a specify interface as part of the criteria (ie, eth0, ppp0, etc.).

Fragment

Rule only refers to second and further fragments of fragmented packets (1 or 0).

Bidir

Makes criteria effective in both directions (1 or 0).

Verbose

Set verbose option for setting rules or list() (1 or 0).

Numeric

Show output from list() in numeric format. No DNS lookups, etc.. (1 or 0).

Log

Enable kernel logging (via syslog, kern.info) of matched packets (1 or 0).

Output

Copy matching packets to the userspace device (advanced).

Mark

Mark matching packets with specified number (advanced).

TOS

Used for modifying the TOS field in the IP header. Takes 2 args, AND and XOR masks, (ie, (TOS => ["0x01", "0x10"])). This feature is highly untested.
The first mask is ANDed with the packets current TOS, and the second mask is XORed with it. Use the following table for reference:

TOS Name Value Typical Uses

Minimum Delay 0x01 0x10 ftp, telnet
Maximum Throughput 0x01 0x08 ftp-data
Maximum Reliability 0x01 0x04 snmp
Minimum Cost 0x01 0x02 nntp

Exact

Display exact numbers in byte counters instead of numbers rounded in Ks, Ms, or Gs (1 or 0).

SYN

Only match TCP packets with the SYN bit set and the ACK and FIN bits cleared (1 or 0).

IPv6 FireWall script is a firewall based on ip6tables.

firewall6.sh 122 lines

#!/bin/bash

# Basic IPv6 FireWall script by Dennis Kruyt (dennis@klingon.nl)
#
# Sun Jan 5 18:26:28 2003 - DK

#debug
#set -x

cd /opt/scripts/firewall

source ./config6
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/bin/X11

# change to script directory
cd ${SCRIPTSDIR}

SCRIPT=${SCRIPTSDIR}/firewall6.sh

case "$1" in
flush)
echo -e "Starting Firewall:"
${IPTABLE6} -F >> /dev/null 2>&1
${IPTABLE6} -X >> /dev/null 2>&1
echo -e "Setting defaults op ACCEPT!"
echo -e "ALERT: no firewall rules active"
#
${IPTABLE6} -P INPUT ACCEPT
${IPTABLE6} -P OUTPUT ACCEPT
${IPTABLE6} -P FORWARD ACCEPT
;;
start|reload)
echo -n "Starting Firewall: "
# paging!
#

# create a backup
TIME=`date +%s`
tar -czf /opt/backups/firewall/firewall.${TIME}.tar.gz /opt/scripts/firewall

# sending mail
mail email@address.com -s "Firewall - (re)started" < $0

# wait
sleep 1

# kerneloptions
echo -n "Loading Kernel options.."
./kernel_options6.sh

echo -n "Flushing and deleting all chains.."
${IPTABLE6} -F >> /dev/null 2>&1
${IPTABLE6} -X >> /dev/null 2>&1

# default policy
echo -n "Setting default policy DROP.."
${IPTABLE6} -P INPUT DROP
${IPTABLE6} -P OUTPUT DROP
${IPTABLE6} -P FORWARD DROP

# ?????????????
#${IPTABLE} -F -t mangle
#${IPTABLE} -t mangle -X

echo -e "Loading chains.."
# create chain blacklist
${IPTABLE6} --new blacklist
#And drop the evil ones
for i in $BLACKLIST6;do
${IPTABLE6} -A blacklist --src $i -j DROP
done

#icmp chain
${IPTABLE6} --new icmprules
${IPTABLE6} -A icmprules -p icmpv6 -j ACCEPT

# create out chain
${IPTABLE6} --new out
#localhost to localhost
${IPTABLE6} -A out --src $LOCALHOST6 --dst $LOCALHOST6 -j ACCEPT
# for now accept all outgoing IPv6 traffic
${IPTABLE6} -A out --src $SIXXS --dst $ANY6 -j ACCEPT

# create in chain
${IPTABLE6} --new in
#localhost to localhost
${IPTABLE6} -A in --src $LOCALHOST6 --dst $LOCALHOST6 -j ACCEPT
# for now accept all incomming IPv6 traffic
${IPTABLE6} -A in --dst $SIXXS --src $ANY6 -j ACCEPT

#All that are in trusted may ssh
for i in $THRUSTED6;do
${IPTABLE6} -A in -p tcp --dst $SIXXS --dport 22 --src $i -j ACCEPT
done

# jump to all ipv6 chains
${IPTABLE6} -A INPUT -j blacklist
${IPTABLE6} -A OUTPUT -j blacklist
${IPTABLE6} -A FORWARD -j blacklist

${IPTABLE6} -A INPUT -j icmprules
${IPTABLE6} -A OUTPUT -j icmprules

${IPTABLE6} -A INPUT -j in
${IPTABLE6} -A OUTPUT -j out

;;
show)
echo -e "Rules in the firewall: ${CHAIN} n"
${IPTABLE6} -L -n
;;
*)
echo -e "Usage: ${SCRIPT} {flush|start|reload|show} n"
exit 1
;;
esac
exit 0

config6 12 lines

export IPTABLE6=/sbin/ip6tables

export SCRIPTSDIR=/opt/scripts/firewall

export EXT="eth0" # device
export SIXXS="3ffe:8114:1000::50f/127" # extern

export ANY6="::/0"
export LOCALHOST6="::1/128"

export THRUSTED6=""

export BLACKLIST6="3ffe:8114:2fff:1391::1"

kernel_options6.sh 7 lines

#!/bin/bash


# forwarding on
#echo "1" > /proc/sys/net/ipv6 blablabla

# Set some other IPv6 proc settings
#echo "1" > /proc/sys/net/ipv6 blablabla

The ICMP Hostname Tools for Linux include a responder daemon, a lookup tool, and a nameswitch module to handle ICMP host name functions.

The NSS module caches all requests (including failures) and honors the TTL value sent by the responding host. It uses a configuration file called /etc/nss-icmp.conf, which controls different aspects of its operation:

* timeout – Sets the timeout in milliseconds for ICMP host name queries, by passing the -t option to idnlookup.
* nocache – Disables the cache.
* ttlnotfound – Sets the TTL for not-found cache entries is seconds. The default is 5 minutes.

Both icmpdnd and idnlookup need to run as root, due to the fact that they use ICMP. Thus, idnlookup needs be installed SUID root.

kfilewatcher project watches for file changes and allows you to react on them.

Example:

kfilewatcher /tmp/test 2>&1 | while read a; do echo "File has changed - doing something"; done

This command does something every time kfilewatcher detects a change. At the moment, the only action is to output "File has changed - doing something", but you can write anything there, e.g.

- backup stuff as soon as it changes
- publish files on your homepage everytime they change
- keep directories in sync