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TABLE OF CONTENTS netutil.doc/arp netutil.doc/ifconfig netutil.doc/inetd netutil.doc/letnet netutil.doc/offline netutil.doc/online netutil.doc/ping netutil.doc/route netutil.doc/arp netutil.doc/arp NAME Arp - address resolution display and control SYNOPSIS arp hostname arp -a [netname | hostname] arp -d hostname arp -s hostname address [temp] [pub] arp -f filename DESCRIPTION Arp displays and modifies the Internet to hardware address translation tables used by the Address Resolution Protocol. The hardware address is a hexadecimal string with each octet separated by a colon, for instance 0:12:ff:a. The length of the address must be correct for the specified interface. OPTIONS none If no options are specified (first form above), arp displays the current ARP entry for hostname. The hostname must either appear in the hostname database (SEE hosts), or be a DARPA Internet address expressed in Internet standard "dot notation". Hostname can also be resolved by nameserver. -a Display all current ARP entries by reading the address mapping table of the specified (sub)network. `Hostname' is used to as default network specifier. -d If an ARP entry exists for the host called hostname, delete it. [This requires super-user privileges.] -s Create an ARP entry for the host called hostname with the hardware station address address. The hardware station address is given as hexadecimal bytes separated by colons. If an ARP entry already exists for hostname, the existing entry is updated with the new information. The entry is permanent unless the word temp is given in the command. If the word pub is specified, the entry is published, which means that this system will act as an ARP server responding to requests for hostname even though the host address is not its own. -f Read file filename and set multiple entries in the ARP tables. Entries in the file should be of the form: hostname address [temp] [pub] Argument meanings are the same as for the -s option. AUTHOR Arp was developed by the University of California, Berkeley, for the BSD Unix system. SEE ALSO ifconfig, netif.protocols/arp, "net/if_arp.h" netutil.doc/ifconfig netutil.doc/ifconfig NAME ifconfig - configure network interface parameters SYNOPSIS ifconfig interface address_family [address [dest_address]] [params] ifconfig interface [address_family] DESCRIPTION ifconfig is used to assign an address to a network interface and/or configure network interface parameters. ifconfig must be used at boot time to define the network address of each interface present on a machine. It can also be used at other times to redefine an interface's address or other operating parameters. PARAMETERS interface A string of the unit name. The device name (e.g. 'a2065.device') concatenated with a slash ('/') and the unit number ('11'), for example 'a2065.device/11' is a legal unit name. address_family Name of protocol on which naming scheme is based. An interface can receive transmissions in differing protocols, each of which may require separate naming schemes. Therefore, it is necessary to specify the address_family, which may affect interpretation of the remaining parameters on the command line. The only address family currently supported is inet (DARPA- Internet family). address Either a host name present in the host name database, (SEE hosts), or a DARPA Internet address expressed in Internet standard "dot notation". The host number can be omitted on 10-Mbyte/second Ethernet interfaces (which use the hardware physical address), and on interfaces other than the first. dest_address Address of destination system. Consists of either a host name present in the host name database, hosts(4), or a DARPA Internet address expressed in Internet standard "dot notation". SWITCHES The following operating parameters can be specified: up Mark an interface "up". Enables interface after an "ifconfig down." Occurs automatically when setting the address on an interface. Setting this flag has no effect if the hardware is "down". down Mark an interface "down". When an interface is marked "down", the system will not attempt to transmit messages through that interface. If possible, the interface will be reset to disable reception as well. This action does not automatically disable routes using the interface. arp Enable the use of Address Resolution Protocol in mapping between network level addresses and link-level addresses (default). -arp Disable the use of Address Resolution Protocol. metric n Set the routing metric of the interface to n, default 0. The routing metric is used by the routing protocol (see gated(1m)). Higher metrics have the effect of making a route less favorable; metrics are counted as additional hops to the destination network or host. debug Enable driver-dependent debugging code. This usually turns on extra console error logging. -debug Disable driver-dependent debugging code. netmask mask (Inet only) Specify how much of the address to reserve for subdividing networks into sub-networks. mask includes the network part of the local address, and the subnet part which is taken from the host field of the address. mask can be specified as a single hexadecimal number with a leading 0x, with a dot-notation Internet address, or with a pseudo- network name listed in the network table networks(4). mask contains 1's for each bit position in the 32-bit address that are to be used for the network and subnet parts, and 0's for the host part. mask should contain at least the standard network portion, and the subnet field should be contiguous with the network portion. broadcast (Inet only) Specify the address that represents broadcasts to the network. The default broadcast address is the address with a host part of all 1's. The command: ifconfig interface/unit with no optional command arguments supplied displays the current configuration for interface. If address_family is specified, ifconfig reports only the details specific to that address family. DIAGNOSTICS Messages indicating that the specified interface does not exist, the requested address is unknown, or the user is not privileged and tried to alter an interface's configuration. EXAMPLES ifconfig lo/0 127.0.0.1 This command marks internal loopback device "UP", and attach an inet address 127.0.0.1 to it. ifconfig cslip.device/0 inet 193.102.4.144 193.102.4.129 This command starts the CSLIP driver, attach an address 193.102.4.144 (our internet address) and a destination address 193.102.4.129 (the internet address of the host you are connecting) to it. ifconfig devs:network/a2065.device/0 inet 193.124.100.64 + netmask 255.255.255.192 -arp This command loads an ethernet driver for the Commodore A2065 Ethernet adapter unit 0, marks it "up", disables ARP protocol for it, attaches an inet address 193.124.100.65 to it and sets its netmask to 255.255.255.192. A bitwise logical and of netmask and address for the interface forms a subnet address, in this case 193.124.100.64. All packets aimed to hosts with same subnet address (that is hosts 193.124.100.64 - 193.124.100.127) are routed to this interface. SEE ALSO netstat, hosts, arp, "net/if.h", "net/sana2tags.h" netutil.doc/inetd netutil.doc/inetd NAME inetd - internet ``super-server'' TEMPLATE inetd DEBUG/S CONFIGFILE DESCRIPTION Inetd should be run when the AmiTCP/IP protocol stack is started. Inetd listens for connections on certain internet sockets. When a connection is found on one of its sockets, it decides what service the socket corresponds to, and invokes a program to service the request. After the program is finished, it continues to listen on the socket (except in some cases which will be described below). Essentially, inetd allows running one daemon to invoke several others, reducing load on the system. PARAMETERS DEBUG Turns on debugging. CONFIGFILE Specifies the configuration file name. CONFIGURATION Upon execution, inetd reads its configuration information from a configuration file which, by default, is AmiTCP:db/inetd.conf. There must be an entry for each field of the configuration file, with entries for each field separated by a tab or a space. Comments are denoted by a ``#'' at the beginning of a line or ``;'' anywhere in the line. There must be an entry for each field. The fields of the configuration file are as follows: service name socket type protocol wait/nowait user server program server program name server program arguments The service-name entry is the name of a valid service in the netdatabase. For ``internal'' services (discussed below), the service name must be the official name of the service. The socket-type should be one of ``stream'', ``dgram'', ``raw'', ``rdm'', or ``seqpacket'', depending on whether the socket is a stream, datagram, raw, reliably delivered message, or sequenced packet socket. Current system supports only stream, datagram and raw protocols. The protocol must be a valid protocol as given in netdatabase. Examples might be ``tcp'' or ``udp''. The wait/nowait entry is useful for datagram sockets only (other sockets should have a ``nowait'' entry in this space). If a datagram server connects to its peer, freeing the socket so inetd can received further messages on the socket, it is said to be a ``multi-threaded'' server, and should use the ``nowait'' entry. For datagram servers which process all incoming datagrams on a socket and eventually time out, the server is said to be ``single-threaded'' and should use a ``wait'' entry. Comsat and talkd are both examples of the latter type of datagram server. The user entry should contain the user name of the user as whom the server should run. This field is for Unix and future compability only. The server-program entry should contain the pathname of the program which is to be executed by inetd when a request is found on its socket. If the server program is resident, the path name should be suppressed. If inetd provides this service internally, this entry should be ``internal''. The server-program-name is CLI command name for the server process. It is shown in the printout of ``status'' command. (Task name of the server process is the service and the peer address, e.g. ``echo [192.233.15.19]''.) This and argument entry are optional. The server program arguments should be just as arguments normally are. Inetd provides several ``trivial'' services internally by use of routines within itself. These services are ``echo'', ``discard'', ``chargen'' (character generator), ``daytime'' (human readable time), and ``time'' (machine readable time, in the form of the number of seconds since mid night, January 1, 1900). All of these services are TCP and UDP based. For details of these services, consult the appropriate RFC from the Network Information Center. Inetd rereads its configuration file when it receives the CTRL-F signal. Services may be added, deleted or modified when the configuration file is reread. HISTORY The inetd command appeared in 4.3BSD system. SEE ALSO netutil.doc/letnet netutil.doc/letnet NAME Letnet - a simple TCP connection tool SYNOPSIS letnet HOSTNAME/A,PORT/A DESCRIPTION Letnet connects to the specified TCP port at the specified host. The data read from standard input is sent to the host and data received from the connection is written to the standard output. Letnet terminates upon shutdown of the socket or receiving SIGBREAKF_CTRL_C signal. ARGUMENTS HOSTNAME/A If there is no name service available, hostname may be given in the Internet dot notation. PORT/A The port identifier is searched from the standard services (SEE ALSO netdb/services) database. A nonstandard service port may be specified in the numeric form, numbers between 1---65535 are acceptable. AUTHOR Pekka Pessi, the AmiTCP/IP Group, Helsinki University of Technology SEE ALSO netdb/services, netdb/hosts netutil.doc/offline netutil.doc/offline NAME Offline - put a SANA-II device offline TEMPLATE Offline DEV=DEVICE devicename[/unit] [UNIT unit] DESCRIPTION Offline sends the S2_OFFLINE command to the given SANA-II device driver and unit. This command is normally used to disconnect SANA-II device driver from the network adapter hardware. Device driver does not accept any more read or write requests. EXAMPLES This command puts the SLIP offline, which frees then the serial port to your use. OFFLINE slip.device/1 SEE ALSO Online, sana2.device/S2_OFFLINE netutil.doc/online netutil.doc/online NAME Online - put a SANA-II device online TEMPLATE Online DEV=DEVICE devicename[/unit] [UNIT unit] DESCRIPTION Online sends the S2_ONLINE command to the given SANA-II device driver and unit. The device driver restarts the network adapter hardware and accepts read and write request again. EXAMPLES This command puts the Commodore Ethernet driver online. Online a2065.device/0 SEE ALSO Offline, sana2.device/S2_ONLINE netutil.doc/ping netutil.doc/ping NAME ping - send ICMP ECHO_REQUEST packets to network hosts SYNOPSIS ping [-dfnqrvR] [-c count] [-i wait] [-l preload] [-p pattern] [-s packetsize] DESCRIPTION Ping uses the ICMP protocol's mandatory ECHO_REQUEST datagram to elicit an ICMP ECHO_RESPONSE from a host or gateway. ECHO_REQUEST datagrams (``pings'') have an IP and ICMP header, followed by a ``struct timeval'' and then an arbitrary number of ``pad'' bytes used to fill out the packet. The options are as follows: Other options are: -c count Stop after sending (and receiving) count ECHO_RESPONSE packets. -d Set the SO_DEBUG option on the socket being used. -f Flood ping. Outputs packets as fast as they come back or one hundred times per second, whichever is more. For every ECHO_REQUEST sent a period ``.'' is printed, while for ever ECHO_REPLY received a backspace is printed. This provides a rapid display of how many packets are being dropped. Only the super-user may use this option. This can be very hard on a network and should be used with caution. -i wait Wait wait seconds between sending each packet. The default is to wait for one second between each packet. This option is incompatible with the -f option. -l preload If preload is specified, ping sends that many packets as fast as possible before falling into its normal mode of behavior. -n Numeric output only. No attempt will be made to lookup symbolic names for host addresses. -p pattern You may specify up to 16 ``pad'' bytes to fill out the packet you send. This is useful for diagnosing data-dependent problems in a network. For example, ``-p ff'' will cause the sent packet to be filled with all ones. -q Quiet output. Nothing is displayed except the summary lines at startup time and when finished. -R Record route. Includes the RECORD_ROUTE option in the ECHO_REQUEST packet and displays the route buffer on returned packets. Note that the IP header is only large enough for nine such routes. Many hosts ignore or discard this option. -r Bypass the normal routing tables and send directly to a host on an attached network. If the host is not on a directly-attached network, an error is returned. This option can be used to ping a local host through an interface that has no route through it. -s packetsize Specifies the number of data bytes to be sent. The default is 56, which translates into 64 ICMP data bytes when combined with the 8 bytes of ICMP header data. -v Verbose output. ICMP packets other than ECHO_RESPONSE that are received are listed. When using ping for fault isolation, it should first be run on the local host, to verify that the local network interface is up and running. Then, hosts and gateways further and further away should be ``pinged''. Round-trip times and packet loss statistics are computed. If duplicate packets are received, they are not included in the packet loss calculation, although the round trip time of these packets is used in calculating the minimum/average/maximum round-trip time numbers. When the specified number of packets have been sent (and received) or if the program is terminated with a SIGINT, a brief summary is displayed. This program is intended for use in network testing, measurement and management. Because of the load it can impose on the network, it is unwise to use ping during normal operations or from automated scripts. ICMP PACKET DETAILS An IP header without options is 20 bytes. An ICMP ECHO_REQUEST packet contains an additional 8 bytes worth of ICMP header followed by an arbitrary amount of data. When a packetsize is given, this indicated the size of this extra piece of data (the default is 56). Thus the amount of data received inside of an IP packet of type ICMP ECHO_REPLY will always be 8 bytes more than the requested data space (the ICMP header). If the data space is at least eight bytes large, ping uses the first eight bytes of this space to include a timestamp which it uses in the computation of round trip times. If less than eight bytes of pad are specified, no round trip times are given. DUPLICATE AND DAMAGED PACKETS Ping will report duplicate and damaged packets. Duplicate packets should never occur, and seem to be caused by inappropriate link-level retransmissions. Duplicates may occur in many situations and are rarely (if ever) a good sign, although the presence of low levels of duplicates may not always be cause for alarm. Damaged packets are obviously serious cause for alarm and often indicate broken hardware somewhere in the ping packet's path (in the network or in the hosts). TRYING DIFFERENT DATA PATTERNS The (inter)network layer should never treat packets differently depending on the data contained in the data portion. Unfortunately, data-dependent problems have been known to sneak into networks and remain undetected for long periods of time. In many cases the particular pattern that will have problems is something that doesn't have sufficient ``transitions'', such as all ones or all zeros, or a pattern right at the edge, such as almost all zeros. It isn't necessarily enough to specify a data pattern of all zeros (for example) on the command line because the pattern that is of interest is at the data link level, and the relationship between what you type and what the controllers transmit can be complicated. This means that if you have a data-dependent problem you will probably have to do a lot of testing to find it. If you are lucky, you may manage to find a file that either can't be sent across your network or that takes much longer to transfer than other similar length files. You can then examine this file for repeated patterns that you can test using the -p option of ping. TTL DETAILS The TTL value of an IP packet represents the maximum number of IP routers that the packet can go through before being thrown away. In current practice you can expect each router in the Internet to decrement the TTL field by exactly one. The TCP/IP specification states that the TTL field for TCP packets should be set to 60, but many systems use smaller values (4.3 BSD uses 30, 4.2 used 15). The AmiTCP/IP uses normally TTL value 30. The maximum possible value of this field is 255, and most systems set the TTL field of ICMP ECHO_REQUEST packets to 255. This is why you will find you can ``ping'' some hosts, but not reach them with telnet or ftp. In normal operation ping prints the ttl value from the packet it re- ceives. When a remote system receives a ping packet, it can do one of three things with the TTL field in its response: · Not change it; this is what Berkeley Unix systems did before the 4.3BSD-Tahoe release. In this case the TTL value in the received packet will be 255 minus the number of routers in the round-trip path. · Set it to 255; this is what AmiTCP/IP and current Berkeley Unix systems do. In this case the TTL value in the received packet will be 255 minus the number of routers in the path from the remote system to the pinging host. · Set it to some other value. Some machines use the same value for ICMP packets that they use for TCP packets, for example either 30 or 60. Others may use completely wild values. BUGS Many Hosts and Gateways ignore the RECORD_ROUTE option. The maximum IP header length is too small for options like RECORD_ROUTE to be completely useful. There's not much that that can be done about this, however. Flood pinging is not recommended in general, and flood pinging the broadcast address should only be done under very controlled conditions. SEE ALSO netstat, ifconfig AUTHOR The ping command originally appeared in 4.3BSD. netutil.doc/route netutil.doc/route NAME route - manually manipulate the routing tables SYNOPSIS route [-n] [-q] [-v] command [modifiers] destination gateway DESCRIPTION Route is a program used to manually manipulate the network routing tables. Options supported by route: -n Prevent attempts to print host and network names symbolically when reporting actions. -v (verbose) Print additional details. -q Suppress all output. Commands accepted by route: add Add a route. delete Delete a specific route. The destination is the destination host or network, gateway is the next-hop gateway to which packets should be addressed. Routes to a particular host are distinguished from those to a network by interpreting the Internet address associated with destination. The optional modifiers -net and -host force the destination to be interpreted as a network or a host, respectively. Otherwise, if the destination has a ``local address part'' of INADDR_ANY, or if the destination is the symbolic name of a network, then the route is assumed to be to a network; otherwise, it is presumed to be a route to a host. For example, 128.32 is interpreted as -host 128.0.0.32; 128.32.130 is interpreted as -host 128.32.0.130; -net 128.32 is interpreted as 128.32.0.0; and -net 128.32.130 is interpreted as 128.32.130.0. To add a default route, give the destination as 'default'. If the route is via an interface rather than via a gateway, the -interface modifier should be specified; the gateway given is the address of this host on the common network, indicating the interface to be used for transmission. The optional -netmask qualifier is used to specify the netmask of the interface. One specifies an additional ensuing address parameter (to be interpreted as a network mask). The implicit network mask generated can be overridden by making sure this option follows the destination parameter. All symbolic names specified for a destination or gateway are looked up first as a host name using gethostbyname(). If this lookup fails, getnetbyname() is then used to interpret the name as that of a network. DIAGNOSTICS add [host | network ] %s: gateway %s flags %x The specified route is being added to the tables. The values printed are from the routing table entry supplied in the IoctlSocket() call. If the gateway address used was not the primary address of the gateway (the first one returned by gethostbyname()), the gateway address is printed numerically as well as symbolically. delete [ host | network ] %s: gateway %s flags %x As above, but when deleting an entry. Network is unreachable An attempt to add a route failed because the gateway listed was not on a directly-connected network. The next-hop gateway must be given. not in table A delete operation was attempted for an entry which wasn't present in the tables. routing table overflow An add operation was attempted, but the system was low on resources and was unable to allocate memory to create the new entry. SEE ALSO ifconfig, protocols/routing HISTORY The route command appeared in 4.2BSD.