Provided by: scamper_20181219-1_amd64 bug

NAME

     scamper — parallel Internet measurement utility

SYNOPSIS

     scamper [-?Dv] [-c command] [-p pps] [-w window] [-M monitorname] [-l listname] [-L listid]
             [-C cycleid] [-o outfile] [-F firewall] [-d debugfile] [-e pidfile] [-O options]
             [-i IPs | -I cmds | -f file | -P [ip:]port | -R name:port | -U unix-dom]

DESCRIPTION

     The scamper utility provides the ability to execute Internet measurement techniques to IPv4
     and IPv6 addresses, in parallel, to fill a specified packets-per-second rate.  Currently,
     scamper supports the well-known traceroute and ping techniques, as well as MDA traceroute,
     alias resolution, some parts of tbit, sting, and neighbour discovery.

     scamper has five modes of operation.  First, scamper can be supplied a list of addresses on
     the command line with the -i option.  scamper will then execute a command with each of the
     supplied addresses, in parallel, and output the results as each task completes.  Second,
     scamper can be supplied a list of addresses in a listfile, one address per line, using the
     -f option.  Third, scamper can be supplied a list of complete commands on the command line
     with the -I option.  Fourth, scamper can be instructed to listen on an IP address and port
     specified with the -P option, or on a unix domain socket specified with the -U option, where
     it can take commands dynamically.  Finally, scamper can be instructed to connect to a remote
     host and port specified with the -R option, where it will be supplied with commands
     dynamically.

     The options are as follows:

     -?      prints a list of command line options and a synopsis of each.

     -v      causes scamper to output version information and exit.

     -D      With this option set, scamper will detach and become a daemon.  Use with the -P or
             -U options.

     -c command
             specifies the command for scamper to use by default. The current choices for this
             option are:
               -  dealias
               -  neighbourdisc
               -  ping
               -  trace
               -  tracelb
               -  sniff
               -  sting
               -  tbit
             scamper uses trace by default.  The available commands and their options are
             documented below.

     -p pps  specifies the target packets-per-second rate for scamper to reach.  By default, this
             value is 20.

     -w window
             specifies the maximum number of tasks that may be probed in parallel.  A value of
             zero places no upper limit.  By default, zero is used.

     -M monitorname
             specifies the canonical name of machine where scamper is run.  This value is used
             when recording the output in a warts output file.

     -l listname
             specifies the name of the list when run from the command line.  This value is used
             when recording the output in a warts output file.

     -L listid
             specifies the numerical id of the list when run from the command line.  This value
             is used when recording the output in a warts output file.

     -C cycleid
             specifies the numerical cycle id to begin with when run from the command line.  This
             value is used when recording the output in a warts output file.

     -o outfile
             specifies the default output file to write measurement results to.  By default,
             stdout is used.

     -F firewall
             specifies that scamper may use the firewall in measurements that require it (tbit
             and sting).  scamper supports two firewall types: IPFW, and PF.  To use the IPFW
             firewall, pass ipfw:<start>-<end>, where <start> is the first rule scamper can use,
             and <end> is the last.  To use the PF firewall, pass pf:<anchor>:<num>, where
             <anchor> is the anchor for scamper to use, and <num> specifies the number of rules
             scamper is allowed to use.

     -d debugfile
             specifies a filename to write debugging messages to.  By default, no debugfile is
             used, though debugging output is sent to stderr if scamper is built for debugging.

     -e pidfile
             specifies a file to write scamper's process ID to.  If scamper is built with
             privilege separation, the ID of the unprivileged process is written.

     -O options
             allows scamper's behaviour to be further tailored.  The current choices for this
             option are:
               -  text: output results in plain text.  Suitable for interactive use.
               -  warts: output results in warts format.  Suitable for archiving measurement
                  results and for use by researchers as it records details that cannot be easily
                  represented with the text option.
               -  json: output results in json format.  Suitable for processing measurement
                  results with a scripting language.  A better approach is to output results in
                  warts format, and to use sc_warts2json(1).
               -  planetlab: tell scamper it is running on a planetlab system.  Necessary to use
                  planetlab's safe raw sockets.
               -  rawtcp: tell scamper to use IPPROTO_RAW socket to send IPv4 TCP probes, rather
                  than a datalink socket.
               -  select: tell scamper to use select(2) rather than poll(2)
               -  kqueue: tell scamper to use kqueue(2) rather than poll(2) on systems where
                  kqueue(2) is available.
               -  epoll: tell scamper to use epoll(7) rather than poll(2) on systems where
                  epoll(7) is available.
               -  tsps: the input file consists of a sequence of IP addresses for pre-specified
                  IP timestamps.
               -  cmdfile: the input file consists of complete commands.
               -  noinitndc: do not initialise the neighbour discovery cache.
               -  outcopy: write a copy of all data written by scamper with the default output
                  method.
               -  debugfileappend: append to the debugfile specified with the -d option.  The
                  default is to truncate the debugfile.
               -  tls: require the use of TLS with the remove controller specified with the -R
                  option.
               -  notls: do not use TLS anywhere in scamper, including tbit.

     -i IP 1..N
             specifies the addresses to probe, on the command line, using the command specified
             with the -c option.

     -f listfile
             specifies the input file to read for target addresses, one per line, and uses the
             command specified with the -c option on each.

     -I cmds.
             specifies complete commands, including target addresses, for scamper to execute.

     -P [ip:]port
             specifies that scamper provide a control socket listening on the specified IP
             address and port on the local host.  If an IP address is not specified, scamper will
             bind to the port specified on the loopback address.

     -R name:port
             specifies that scamper connects to a specified remote host and port to receive
             commands.

     -U unix domain socket
             specifies that scamper provide a control socket listening on the specified socket in
             the unix domain.

TRACE OPTIONS

     The trace command is used for conducting traceroute.  The following variations of the
     traceroute(8) options are available:

     trace [-MQT] [-c confidence] [-d dport] [-f firsthop] [-g gaplimit] [-G gapaction]
     [-l loops] [-m maxttl] [-o offset] [-O option] [-p payload] [-P method] [-q attempts]
     [-s sport] [-S srcaddr] [-t tos] [-U userid] [-w wait] [-W wait-probe] [-z gss-entry]
     [-Z lss-name]

     -c confidence
             specifies that a hop should be probed to a specified confidence level (95% or 99%)
             to be sure the trace has seen all interfaces that will reply for that hop.

     -d dport
             specifies the base destination port value to use for UDP-based and TCP-based
             traceroute methods.  For ICMP-paris, this option sets the ICMP checksum value.

     -f firsthop
             specifies the TTL or HLIM value to begin probing with.  By default, a first hop of
             one is used.

     -g gaplimit
             specifies the number of unresponsive hops permitted until a check is made to see if
             the destination will respond.  By default, a gap limit of 5 hops is used.  Setting
             the gap limit to 0 disables the gap limit, but doing this is not recommended.

     -G gapaction
             specifies what should happen if the gaplimit condition is met.  A value of 1
             (default) means halt probing, while a value of 2 means send last-ditch probes.

     -m maxttl
             specifies the maximum TTL or HLIM value that will be probed.  By default, there is
             no restriction, apart from the 255 hops that the Internet protocols allow.

     -M      specifies that path MTU discovery (PMTUD) should be attempted for the path when the
             initial traceroute completes.  scamper will not conduct PMTUD unless it is probing a
             responsive destination, as otherwise there is no way to distinguish all packets
             being lost from just big packets (larger than MTU) being lost.

     -l loops
             specifies the maximum number of loops permitted until probing stops.  By default, a
             value of one is used.  A value of zero disables loop checking.

     -o offset
             specifies the fragmentation offset to use in probes.  By default, no offset is used.

     -O option
             specifies optional arguments to use.  The current choices for this option are:
               -  dl specifies that the datalink socket should be used to timestamp packets, and
                  to receive certain packets.
               -  dtree-noback specifies that the traceroute should not do backwards probing when
                  using doubletree.

     -p payload
             specifies the payload of the probe to use as a base.  The payload is specified in
             hexadecimal.  Note that the payload supplied is merely a base; the first 2 bytes may
             be modified to accomplish ICMP-Paris and UDP-Paris traceroute.

     -P method
             specifies the traceroute method to use.  scamper currently supports five different
             probe methods: UDP, ICMP, UDP-paris, ICMP-paris, TCP, and TCP-ACK.  By default, UDP-
             paris is used.

     -q attempts
             specifies the maximum number of attempts to obtain a response per hop.  By default,
             a value of two is used.

     -Q      specifies that all allocated probes are sent, regardless of how many responses have
             been received.

     -s sport
             specifies the source port value to use.  For ICMP-based methods, this option
             specifies the ICMP identifier to use.

     -S srcaddr
             specifies the source address to use in probes.  The address cannot be spoofed.

     -t tos  specifies the value to set in the IP ToS/DSCP + ECN byte.  By default, this byte is
             set to zero.

     -T      specifies that time exceeded messages from the destination do not cause the trace to
             be defined as reaching the destination.

     -U userid
             specifies an unsigned integer to include with the data collected; the meaning of the
             user-id is entirely up to the user and has no effect on the behaviour of traceroute.

     -w wait
             specifies how long to wait, in seconds, for a reply.  By default, a value of 5 is
             used.

     -W wait-probe
             specifies the minimum time to wait, in 10s of milliseconds, between sending
             consecutive probes.  By default the next probe is sent as soon as possible.

     -z gss-entry
             specifies an IP address to halt probing when encountered; used with the double-tree
             algorithm.

     -Z lss-name
             specifies the name of the local stop set to use when determining when to halt
             probing backwards; used with the double-tree algorithm.

PING OPTIONS

     The ping command is used for conducting ping.  The following variations of the ping(8)
     options are available:

     ping [-R] [-B payload] [-c probecount] [-C icmp-sum] [-d dport] [-F sport] [-i wait]
     [-m ttl] [-M MTU] [-o replycount] [-O options] [-p pattern] [-P method] [-s size]
     [-S srcaddr] [-T timestamp] [-U userid] [-W timeout] [-z tos]

     -B payload
             specifies, in a hexadecimal string, the payload to include in each probe.

     -c probecount
             specifies the number of probes to send before exiting.  By default, a value of 4 is
             used.

     -C icmp-sum
             specifies the ICMP checksum to use when sending a probe.  The payload of each probe
             will be manipulated so that the checksum is valid.

     -d dport
             specifies the destination port to use in each TCP/UDP probe, and the first ICMP
             sequence number to use in ICMP probes.

     -F sport
             specifies the source port to use in each TCP/UDP probe, and the ICMP ID to use in
             ICMP probes.

     -i wait
             specifies the length of time to wait, in seconds, between probes.  By default, a
             value of 1 is used.

     -m ttl  specifies the TTL value to use for outgoing packets.  By default, a value of 64 is
             used.

     -M MTU  specifies a pseudo MTU value.  If the response packet is larger than the pseudo MTU,
             an ICMP packet too big (PTB) message is sent.

     -o replycount
             specifies the number of replies required at which time probing may cease.  By
             default, all probes are sent.

     -O options
             The current choices for this option are:
               -  dl specifies that the ping should use datalink sockets, rather than raw
                  sockets.
               -  spoof specifies that the source address is to be spoofed according to the
                  address specified with the -S option.  The address scamper would otherwise use
                  as the source address is embedded in the payload of the probe.
               -  tbt specifies that the goal of the ping is to obtain fragmented responses, so
                  that the -c option specifies how many packets to send, and the -o option
                  specifies how many fragmented responses are desired.

     -p pattern
             specifies the pattern, in hex, to use in probes.  Up to 16 bytes may be specified.
             By default, each probe's bytes are zeroed.

     -P method
             specifies the type of ping packets to send.  By default, ICMP echo requests are
             sent.  Choices are: icmp-echo, icmp-time, tcp-syn, tcp-ack, tcp-ack-sport, udp, and
             udp-dport.

     -R      specifies that the record route IP option should be used.

     -s size
             specifies the size of the probes to send.  The probe size includes the length of the
             IP and ICMP headers.  By default, a probe size of 84 bytes is used for IPv4 pings,
             and 56 bytes for IPv6 pings.

     -S srcaddr
             specifies the source address to use in probes.  The address can be spoofed if -O
             spoof is included.

     -T timestamp
             specifies that an IP timestamp option be included.  The timestamp option can either
             be: tsprespec where IP addresses of devices of interest can be specified; tsonly,
             where timestamps are embedded by devices but no IP addresses are included; and
             tsandaddr, where timestamps and IP addresses are included by devices in the path.
             See the examples section for more information.

     -U userid
             specifies an unsigned integer to include with the data collected; the meaning of the
             user-id is entirely up to the user and has no effect on the behaviour of ping.

     -W timeout
             specifies how long to wait for responses after the last ping is sent.  By default
             this is one second.

     -z tos  specifies the value to use in the IPv4 ToS/DSCP + ECN byte.  By default, this byte
             is set to zero.

DEALIAS OPTIONS

     The dealias command is used to send probes for the purpose of alias resolution.  It supports
     the mercator technique, where aliases are inferred if a router uses a different address when
     sending an ICMP response; the ally technique, where aliases are inferred if a sequence of
     probes sent to alternating IP addresses yields responses with incrementing, interleaved IP-
     ID values; radargun, where probes are sent to a set of IP addresses in multiple rounds and
     aliases are inferred by post-processing the results; prefixscan, where an alias is searched
     in a prefix for a specified IP address; and bump, where two addresses believed to be aliases
     are probed in an effort to force their IP-ID values out of sequence.  The following options
     are available for the scamper dealias command:

     dealias [-d dport] [-f fudge] [-m method] [-o replyc] [-O option] [-p probe-options]
     [-q attempts] [-r wait-round] [-s sport] [-t ttl] [-U userid] [-w wait-timeout]
     [-W wait-probe] [-x exclude]

     -d dport
             specifies the destination port to use when sending probes.  Only valid for the
             mercator technique; destination ports can be specified in probedefs defined with -p
             for other alias resolution methods.

     -f fudge
             specifies a fudge factor for alias matching. Defaults to 200. Only valid for ally
             and bump.

     -m method
             specifies which method to use for alias resolution.  Valid options are: ally, bump,
             mercator, prefixscan, and radargun.

     -o replyc
             specifies how many replies to wait for. Only valid for prefixscan.

     -O option
             allows alias resolution behaviour to be further tailored.  The current choices for
             this option are:
               -  inseq where IP-ID values are required to be strictly in sequence (with no
                  tolerance for packet reordering)
               -  shuffle randomise the order of probes sent each round; only valid for radargun
                  probing.
               -  nobs do not allow for byte swapped IP-ID values in responses.  Valid for ally
                  and prefixscan.

     -p probedef
             specifies a definition for a probe. Possible options are:

             -c sum  specifies what ICMP checksum to use for ICMP probes.  The payload of the
                     probe will be altered appropriately.

             -d dst-port
                     specifies the destination port of the probe.  Defaults to 33435.

             -F src-port
                     specifies the source port of the probe.  Defaults to (pid & 0x7fff) +
                     0x8000.

             -i IP   specifies the destination IP address of the probe.

             -M mtu  specifies the pseudo MTU to use when soliciting fragmented responses.

             -P method
                     specifies which method to use for the probe.  Valid options are: udp, udp-
                     dport, tcp-ack, tcp-ack-sport, tcp-syn-sport, and icmp-echo.

             -s size
                     specifies the size of the probes to send.

             -t ttl  specifies the IP time to live of the probe.
             The ally method accepts up to two probe definitions; the prefixscan method expects
             one probe definition; radargun expects at least one probe definition; bump expects
             two probe definitions.

     -q attempts
             specifies how many times a probe should be retried if it does not obtain a useful
             response.

     -r wait-round
             specifies how many milliseconds to wait between probing rounds with radargun.

     -s sport
             specifies the source port to use when sending probes. Only valid for mercator.

     -t ttl  specifies the time-to-live of probes sent. Only valid for mercator.

     -U userid
             specifies an unsigned integer to include with the data collected; the meaning of the
             user-id is entirely up to the user and has no effect on the behaviour of dealias.

     -w wait-timeout
             specifies how long to wait in seconds for a reply from the remote host.

     -W wait-probe
             specifies how long to wait in milliseconds between probes.

     -x exclude
             specifies an IP address to exclude when using the prefixscan method.  May be
             specified multiple times to exclude multiple addresses.

NEIGHBOUR DISCOVERY OPTIONS

     The neighbourdisc command attempts to find the layer-2 address of a given IP address using
     IPv4 ARP or IPv6 Neighbour Discovery.  The following options are available for the scamper
     neighbourdisc command:

     neighbourdisc [-FQ] [-i interface] [-o reply-count] [-q attempts] [-w wait]

     -F      specifies that we only want the first response.

     -Q      specifies that we want to send all attempts.

     -i interface
             specifies the name of the interface to use for neighbour discovery.

     -o reply-count
             specifies how many replies we wait for.

     -q attempts
             specifies how many probes we send out.

     -w wait
             specifies how long to wait between probes in milliseconds.  Defaults to 1000.

TBIT OPTIONS

     The tbit command can be used to infer TCP behaviour of a specified host.  At present, it
     implements tests to check the ability of the host to respond to ICMP Packet Too Big
     messages, respond to Explicit Congestion Notification, test Selective Acknowledgement
     behaviour, the Initial Congestion Window, and resilience to Blind Attacks.  The following
     options are available for the scamper tbit command:

     tbit [-t type] [-p app] [-d dport] [-s sport] [-a acks] [-b ASN] [-i ICW] [-f cookie]
     [-L limit] [-m mss] [-M mtu] [-o offset] [-O option] [-P ptbsrc] [-q attempts] [-S srcaddr]
     [-T ttl] [-u url] [-U userid] [-w wscale]

     -t type       specifies which type of testing to use.  Valid options are: pmtud, ecn, null,
                   sack-rcvr, icw, abc, blind-rst, blind-syn, blind-data.

     -p app        specifies what kind of traffic to generate for testing.  Destination port
                   defaults the application standard port.  Valid applications are: http, bgp.

     -d dport      specifies the destination port for the packets being sent.  Defaults are
                   application-specific.

     -s sport      specifies the source port for the packets being sent.  Default is based of the
                   scamper process id.

     -a acks       specifies the sequence of packets that should be acknowledged as part of the
                   ABC test.

     -b ASN        specifies the autonomous system number (ASN) that should be used when
                   establishing a BGP session.

     -i ICW        specifies the initial congestion window (ICW) that we expect from the peer
                   when conducting the ABC test.

     -f cookie     specifies the TCP fast open cookie that should be used when establishing a TCP
                   connection.

     -L limit      test the response to a theoretical limit (L) value with ABC.

     -m mss        specifies the maximum segment size to advertise to the remote host.

     -M mtu        specifies the MTU to use in a Packet Too Big message.

     -o offset     specifies the sequence number offset to use when conducting blind-syn and
                   blind-rst tests, and the acknowledgement number offset to use when conducting
                   a blind-data test.

     -O option     allows tbit behaviour to be further tailored.  The current choices for this
                   option are:
                     -  blackhole: for PMTUD testing, do not send Packet Too Big messages; this
                        tests to ability of a host to infer a PMTUD blackhole and work around it.
                     -  tcpts: advertise support for TCP timestamps when establishing a TCP
                        connection.  If the peer supports TCP timestamps, embed timestamps in
                        data packets.
                     -  ipts-syn: use the timestamp IP option in a SYN packet when attempting to
                        establish a TCP connection.
                     -  iprr-syn: use the record-route IP option in a SYN packet when attempting
                        to establish a TCP connection.
                     -  ipqs-syn: use the quick-start IP option in a SYN packet when attempting
                        to establish a TCP connection.
                     -  sack: advertise support for TCP selective acknowledgements (SACK) when
                        establishing a TCP connection.
                     -  fo: advertise support for TCP fast open using the official IANA number
                        assigned for fast open.
                     -  fo-exp: advertise support for TCP fast open using the testing number
                        assigned by IANA for fast open.

     -P ptbsrc     specifies the source address that should be used to send Packet Too Big
                   messages in the pmtud test.

     -q attempts   specifies the number of attempts to make with each packet to reduce false
                   inferences caused by packet loss.

     -S srcaddr    specifies the source address that should be used in TCP packets sent by the
                   tbit test.

     -T ttl        specifies the IP time-to-live value that should be used in TCP packets sent by
                   the tbit test.

     -u url        specifies a url to use when using the http application method.  If the url
                   starts with https, the tbit test begins with a TLS handshake.

     -U userid     specifies an unsigned integer to include with the data collected; the meaning
                   of the user-id is entirely up to the user and has no effect on the behaviour
                   of tbit.

     -w wscale     specifies the window scale option to use when establishing the TCP connection.

TRACELB OPTIONS

     The tracelb command is used to infer all per-flow load-balanced paths between a source and
     destination.  The following options are available for the scamper tracelb command:

     tracelb [-c confidence] [-d dport] [-f firsthop] [-g gaplimit] [-P method] [-q attempts]
     [-Q maxprobec] [-s sport] [-t tos] [-U userid] [-w wait-timeout] [-W wait-probe]

     -c confidence
                   specifies the level of confidence we want to attain that there are no more
                   parallel load balanced paths at a given hop.  Valid values are 95 (default)
                   and 99, for 95% confidence and 99% confidence respectively.

     -d dport      specifies the base destination port to use. Defaults to 33435, the default
                   used by traceroute(8).

     -f firsthop   specifies how many hops away we should start probing.

     -g gaplimit   specifies how many consecutive unresponsive hops are permitted before probing
                   down a branch halts.  Defaults to three.

     -P method     specifies which method we should use to do the probing.  Valid options are:
                   "udp-dport", "icmp-echo", "udp-sport", "tcp-sport", and "tcp-ack-sport".
                   Defaults to "udp-dport".

     -q attempts   specifies how many probes we should send in an attempt to receive a reply.
                   Defaults to 2.

     -Q maxprobec  specifies the maximum number of probes we ever want to send.  Defaults to
                   3000.

     -s sport      specifies to the source port to use when sending probes.  Default based on
                   process ID.

     -t tos        specifies the value for the IP Type-of-service field for outgoing probes.
                   Defaults to 0.

     -U userid     specifies an unsigned integer to include with the data collected; the meaning
                   of the user-id is entirely up to the user and has no effect on the behaviour
                   of tracelb.

     -w wait-timeout
                   specifies in seconds how long to wait for a reply to a probe. Defaults to 5.

     -W wait-probe
                   specifies in 1/100ths of seconds how long to wait between probes.  Defaults to
                   25 (i.e. 250ms).

STING OPTIONS

     The sting command is used to infer one-way loss using an algorithm with TCP probes.  It
     requires the firewall be enabled in scamper using the -F option.  The following options are
     available for the scamper sting command:

     sting [-c count] [-d dport] [-f distribution] [-h request] [-H hole] [-i inter] [-m mean]
     [-s sport]

     -c count      specifies the number of samples to make.  By default 48 samples are sent, as
                   this value is the current default of the FreeBSD TCP reassembly queue length.
                   Sting 0.7 uses 100 samples.

     -d dport      specifies the base destination port to use.  Defaults to 80, the default port
                   used by the HTTP protocol.

     -f distribution
                   specifies the delay distribution of samples.  By default a uniform
                   distribution is constructed.  Other distributions are currently not
                   implemented in scamper's implementation of sting.

     -h request    specifies the default request to make.  Currently not implemented.

     -H hole       specifies the size of the initial hole left in the request.  The default is 3
                   bytes, the same as sting-0.7.

     -i inter      specifies the inter-phase delay between data seeding and hole filling, in
                   milliseconds.  By default, sting waits 2000ms between phases.

     -m mean       specifies the mean rate to send packets in the data phase, in milliseconds.
                   By default, sting waits 100ms between probes.

     -s sport      specifies to the source port to use when sending probes.  Default is based on
                   the process ID.

SNIFF OPTIONS

     The sniff command is used to capture packets matching a specific signature.  At present, the
     only supported signature is ICMP echo packets with a specific ID value, or packets
     containing such a quote.  The following options are available for the scamper sniff command:

     sting [-c limit-pktc] [-G limit-time] [-S ipaddr] [-U userid] <expression>

     -c limit-pktc
                   specifies the maximum number of packets to capture.

     -G limit-time
                   specifies the maximum time, in seconds, to capture packets.

     -S ipaddr     specifies the IP address that packets must arrive using.  scamper uses the IP
                   address to identify the appropriate interface to listen for packets.

     -U userid     specifies an unsigned integer to include with the data collected; the meaning
                   of the user-id is entirely up to the user and has no effect on the behaviour
                   of sniff.

     The sole supported expression is icmp[icmpid] == X, where X is the ICMP-ID to select.

DATA COLLECTION FEATURES

     scamper has two data output formats.  The first is a human-readable format suitable for one-
     off data collection and measurement.  The second, known as warts, is a binary format that
     records much more meta-data and is more precise than the human-readable format.

     scamper is designed for Internet-scale measurement, where large lists of targets are
     supplied for probing.  scamper has the ability to probe multiple lists simultaneously, with
     each having a mix rate that specifies the priority of the list.  scamper can also make
     multiple cycles over a list of addresses.

     When writing output to a warts file, scamper records details of the list and cycle that each
     measurement task belongs to.

CONTROL SOCKET

     When started with the -P option, scamper allows inter-process communication via a TCP socket
     bound to the supplied port on the local host.  This socket is useful for controlling the
     operation of a long-lived scamper process.  A client may interact with scamper by using
     telnet(1) to open a connection to the supplied port.

     The following control socket commands are available.

     exit
          The exit command closes the current control socket connection.

     attach
          The attach command changes how scamper accepts and replies to commands, returning
          results straight over the control socket. See ATTACH section below for details on which
          commands are accepted.

     get argument
          The get command returns the current setting for the supplied argument.  Valid argument
          values are: holdtime, monitorname, pid, pps, sport, version.

     set argument ...
          The set command sets the current setting for the supplied argument.  Valid argument
          values are: holdtime, monitorname, pps.

     source argument ...

          add arguments
               The source add command allows a new input source to be added.  It accepts the
               following arguments:

               name string
                    The name of the source.  This parameter is mandatory.

               descr string
                    An optional string describing the source.

               command string
                    The command to execute for each address supplied.  If not supplied, the
                    default command is used.

               list_id uint32_t
                    An optional numeric list identifier, assigned by a human.  If not supplied, a
                    value of zero is used.

               cycle_id uint32_t
                    An optional numeric initial cycle identifier to use, assigned by a human.  If
                    not supplied, a value of one is used.

               priority uint32_t
                    An optional numeric value that specifies the mix rate of measurements from
                    the source compared to other sources.  If not supplied, a mix rate of one is
                    used.  A value of zero causes the source to be created, but not actively
                    used.

               outfile string
                    The name of the output file to write results to, previously defined with
                    outfile open.  If not supplied, the default output file is used.

               file string
                    The name of the input file to read target addresses from.  This parameter is
                    mandatory if the source is a managed source.

               cycles integer
                    The number of cycles to make over the target address file.  If zero, scamper
                    will loop indefinitely over the file.  This parameter is ignored unless a
                    managed source is defined.

               autoreload [on | off]
                    This parameter specifies if the target address file should be re-read
                    whenever a cycle is completed, or if the same set of target addresses as the
                    previous cycle should be used.  If not specified, the file is not
                    automatically reloaded at cycle time.

          update name arguments
               The source update command allows some properties of an existing source to be
               modified.  The source to update is specified with the name parameter.  Valid
               parameters are: autoreload, cycles, and priority.

          list ...
               The source list command provides a listing of all currently defined sources.  The
               optional third name parameter restricts the listing to the source specified.

          cycle name
               The source cycle command manually inserts a cycle marker in an adhoc source.

          delete name
               The source delete command deletes the named source, if possible.

     outfile argument ...
          The outfile commands provide the ability to manage output files.  It accepts the
          following arguments:

          open ...
               The outfile open command allows a new output file to be defined.  It accepts the
               following parameters:

               name alias
                    The alias of the output file.  This parameter is mandatory.

               file string
                    The filename of the output file.  This parameter is mandatory.

               mode [truncate | append]
                    How the file will be opened.  If the append mode is used, any existing file
                    with the specified name will be appended to.  If the truncate mode is used,
                    any existing file will be truncated when it is opened.

          close alias
               The outfile close command allows an existing output file to be closed.  The
               mandatory alias parameter specifies which output file to close.  An output file
               that is currently referenced is not able to be closed.  To close a file that is
               currently referenced, a new outfile must be opened, and then the outfile swap
               command be used.

          swap alias1 alias2
               The outfile swap command swaps the file associated with each output file.

          list
               The outfile list command outputs a list of the existing outfiles.

     observe sources
          This command allows for monitoring of source events.  When executed, the control socket
          will then supply event notices whenever a source is added, updated, deleted, finished,
          or cycled.  Each event is prefixed with a count of the number of seconds elapsed since
          the Unix epoch.  The following examples illustrate the event monitoring capabilities:

                EVENT 1169065640 source add name 'foo' list_id 5 priority 1
                EVENT 1169065641 source update 'foo' priority 15
                EVENT 1169065642 source cycle 'bar' id 2
                EVENT 1169065650 source finish 'bar'
                EVENT 1169065661 source delete 'foo'

     shutdown argument
          The shutdown argument allows the scamper process to be exited cleanly.  The following
          arguments are supported

          done
               The shutdown done command requests that scamper shuts down when the current tasks,
               as well as all remaining cycles, have completed.

          flush
               The shutdown flush command requests that scamper flushes all remaining tasks
               queued with each list, finishes all current tasks, and then shuts down.

          now  The shutdown now command causes scamper to shutdown immediately.  Unfinished tasks
               are purged.

          cancel
               The shutdown cancel command cancels any pending shutdown.

ATTACH MODE

     In attach mode, none of the usual interactive mode commands are usable.  Instead, commands
     may be entered directly and results will be sent back directly over the control socket.
     Commands are specified just as they would be with the -I flag for a command-line invocation
     of scamper.  Replies are split into lines by single \n characters and have one of the
     following formats:

     ERR ...
          A line starting with the 3 characters "ERR" indicates an error has occurred.  The rest
          of the line will contain an error message.

     OK id-num
          A line with the 2 characters "OK" indicates that scamper has accepted the command.
          scamper versions after 20110623 return an id number associated with the command, which
          allow the task to be halted by subsequently issuing a "halt" instruction.

     MORE
          A line with just the 4 characters "MORE" indicates that scamper has the capacity to
          accept more probing commands to run in parallel.

     DATA length
          A line starting with the 4 characters "DATA" follow by a space then a base-10 number
          indicates the start of result.  length specifies the number of characters of the data,
          including newlines. The data is in binary warts format and uuencoded before
          transmission.

     To exit attached mode the client must send a single line containing "done".  To halt a
     command that has not yet completed, issue a "halt" instruction with the id number returned
     when the command was accepted as the sole parameter.

EXAMPLES

     To use the default traceroute command to trace the path to 192.0.2.1:

          scamper -i 192.0.2.1

     To infer Path MTU changes in the network and associate them with a traceroute path:

          scamper -I "trace -P udp-paris -M 192.0.2.1"

     To use paris traceroute with ICMP probes, using 3 probes per hop, sending all probes,
     writing to a specified warts file:

          scamper -O warts -o file.warts -I "trace -P icmp-paris -q 3 -Q 192.0.2.1"

     To ping a series of addresses defined in filename, probing each address 10 times:

          scamper -c "ping -c 10" filename

     Care must be taken with shell quoting when using commands with multiple levels of quoting,
     such as when giving a probe description with a dealias command.  The following sends UDP
     probes to alternating IP addresses, one second apart, and requires the IP-ID values returned
     to be strictly in sequence.

          scamper -O warts -o ally.warts -I "dealias -O inseq -W 1000 -m ally -p '-P udp -i
          192.0.2.1' -p '-P udp -i 192.0.2.4'"

     Alternatively, the following accomplishes the same, but without specifying the UDP probe
     method twice.

          scamper -O warts -o ally.warts -I "dealias -O inseq -W 1000 -m ally -p '-P udp'
          192.0.2.1 192.0.2.4"

     The following command scans 198.51.100.0/28 for a matching alias to 192.0.2.4, but skips
     198.51.100.3.

          scamper -O warts -o prefixscan.warts -I "dealias -O inseq -W 1000 -m prefixscan -p '-P
          udp' -x 198.51.100.3 192.0.2.4 198.51.100.0/28"

     The following uses UDP probes to enumerate all per-flow load-balanced paths towards
     192.0.2.6 to 99% confidence; it varies the source port with each probe.

          scamper -I "tracelb -P udp-sport -c 99 192.0.2.6"

SEE ALSO

     ping(8), traceroute(8), libscamperfile(3), sc_ally(1), sc_analysis_dump(1), sc_attach(1),
     sc_ipiddump(1), sc_filterpolicy(1), sc_remoted(1), sc_speedtrap(1), sc_tbitblind(1),
     sc_tracediff(1), sc_uptime(1), sc_wartscat(1), sc_wartsdump(1), sc_warts2json(1),
     sc_warts2pcap(1), sc_warts2text(1),

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AUTHORS

     scamper was written by Matthew Luckie <mjl@luckie.org.nz>.  Alistair King contributed an
     initial implementation of Doubletree; Ben Stasiewicz contributed an initial implementation
     of TBIT's PMTUD test; Stephen Eichler contributed an initial implementation of TBIT's ECN
     test; Boris Pfahringer adapted scamper to use GNU autotools, modularised the tests, and
     updated this man page.  Brian Hammond of Internap Network Services Corporation provided an
     initial implementation of scamper's json output format.  Tiange Wu contributed an initial
     implementation of the blind in-window TBIT test, and Robert Beverly contributed BGP protocol
     support for TBIT.

ACKNOWLEDGEMENTS

     scamper development was initially funded by the WIDE project in association with CAIDA.
     Boris' work was funded by the University of Waikato's Centre for Open Source Innovation.