icmpinfo(8) [debian man page]
ICMPINFO(8) System Manager's Manual ICMPINFO(8) NAME
icmpinfo - interpret ICMP messages SYNOPSIS
icmpinfo [-v[v[v]]] [-n] [-p] [-s] [-l] [-k] DESCRIPTION
Icmpinfo is a tool for looking at the ICMP messages received on the running host. It can be used to detect and record 'bombs' as well as various network problems. The output format is as follows (all on one line): MMM DD HH:MM:SS ICMP_type[sub-type] < sender_ip [sender_name] > unreach_ip [unreach_name] sp=source_port dp=dest_port seq=sequence sz=packet_size In normal operation, icmpinfo will only report on "weird" packets, mainly icmp_unreachable. OPTIONS
-v Give information about all icmp packets, excepts pings. -vv Give about pings too (i.e. icmp_echo_reply). -vvv Include an ascii/hex dump of each packet -n Avoid name queries - just give IP addresses. (use this option when running unattended on name server hosts (to avoid possible loop- ing)) -p Avoid port number to service name decoding. -s Show the interface ip that received the packet. Useful only if your host has several network interfaces. In this case an '- my_ip [my_name]' is added between the sender and unreach ip and name fields. -l Forks and use the syslog(3) facility to record events (recommended use). (root only option). -k Kills the background process started with the -l option. WARNINGS
The packet decoding is planned for ICMP Unreachable outputs and might not be significant for all other Icmp types. Output can be shorter when implied by the packet size or the icmp type. AUTHOR
Laurent Demailly <dl@hplyot.obspm.fr>. Free software. dl's free utilities V1.11 - 28 August 1995 ICMPINFO(8)
Check Out this Related Man Page
icmp(n) Tnm Tcl Extension icmp(n) __________________________________________________________________________________________________________________________________________________ NAME
icmp - Send ICMP messages to hosts on the Internet. _________________________________________________________________ DESCRIPTION
The icmp command allows to send Internet Control Messages (ICMP) (RFC 792, RFC 1122) to a list of hosts on the Internet. ICMP messages can be used to check whether hosts are reachable. The icmp command can also be used to trace routes to Internet hosts by sending UDP datagrams to unused UDP ports and interpreting the ICMP responses (Van Jacobsen and Steve Deering algorithm). ICMP COMMAND
The icmp command always accepts a list of target hosts. ICMP messages are send to the targets in a round-robin fashion which allows to check entire IP address ranges or a list of core routers efficiently. The user of the icmp command should be careful not to flood a network with ICMP requests. icmp [options] Invoking the icmp command with options but without any command arguments allows to retrieve and change the default values. See the description of supported options below. Default values are bound to a Tcl interpreter which allows to have multiple Tcl interpreter with different defaults. icmp [options] echo hosts The icmp echo command can be used to test the reachability of IP devices by sending ICMP echo requests to the hosts. The command returns a list of host / round trip time pairs. The round trip time is returned in milliseconds. A negative round trip time indi- cates that a host did not respond in the timeout interval. icmp [options] mask hosts The icmp mask command sends ICMP mask requests and returns a list of host / netmask pairs. The mask will be set to 0.0.0.0 if a host does not respond to ICMP mask requests. icmp [options] timestamp hosts The icmp timestamp command retrieves timestamps using the ICMP timestamp request. This command returns an estimate of the time dif- ference between local time and the time on the hosts given in hosts. The command returns a list of host / time offset pairs. The time offset is returned in milliseconds. An empty time offset indicates that a host did not respond in the timeout interval. icmp [options] ttl num hosts The icmp ttl command, which may not be supported on every operating system, sends a UDP packet to an unused port number with the time to live field of the IP header set to num. This command returns a list of host / round trip time pairs, where the host is the IP device being num hops away. The round trip time is returned in milliseconds. A negative round trip time indicates that a host did not respond in the timeout interval. icmp [options] trace num hosts The icmp trace command works similar to the icmp ttl command but it always returns the destination address even when the responding host chooses another interface with a different IP address to send the reply. This can be used to trace a route to a host since the command returns the host that discards the packet if it does not reach the destination. ICMP OPTIONS
The following options control how ICMP requests are send and how the icmp command deals with lost ICMP packets. -timeout time The -timeout option defines the time the icmp command will wait for a response. The time is defined in seconds with a default of 5 seconds. -retries number The -retries option defines how many times a request is retransmitted during the timeout interval. The default number of retries is 2. -delay time The -delay option defines the minimum delay between two outgoing ICMP packets. The delay time is defined in milliseconds with a default delay of 0 milliseconds. Delays are useful to reduce the load on intermediate devices like gateways or bridges. -size number The -size option allows to control the size of ICMP packets. The number defines the size of ICMP packets in bytes with a default size of 64 bytes. Sizes smaller than 64 bytes are silently rounded to 64 bytes. BUGS
The icmp command requires the setuid root program ntping(8) because sending icmp packets requires access to raw sockets on most operating systems. SEE ALSO
scotty(1), ntping(8), Tnm(n), Tcl(n) AUTHORS
Juergen Schoenwaelder <schoenw@cs.utwente.nl> Tnm icmp(n)