a2) United States Patent
`US 6,560,642 B1
`(10) Patent No.:
`May 6, 2003
`(45) Date of Patent:
`Nurmann
`
`US006560642B1
`
`(54) METHOD OF ESTABLISHING AN INTERNET
`PROTOCOL NETWORK UTILIZING IP
`GATEWAY THAT FUNCTIONSAS EITHER
`OR BOTH DHCP CLIENT AND DHCP
`SERVER
`
`(75)
`
`Inventor:
`
`Jens Nurmann, Aachen (DE)
`
`(73) Assignee: ELSA AG, Aachen (DE)
`
`(*) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 0 days.
`
`(21) Appl. No.: 09/425,863
`
`(22) Filed:
`
`Oct. 23, 1999
`
`(30)
`
`Foreign Application Priority Data
`
`Oct. 26, 1998
`
`(DE) oon. eee esseeeeteeteeeeneenseetens 198 49 170
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`Q/L996 NOITIS w.icccccssseeceeeees 395/200.1
`2/1999 Bereiter ....
`eevee 709/220
`
`
`5/2000 Fijolek et al... 709/225
`5/2000 Subramaniametal. ..... 709/220
`9/2000 Mellquist ..............0 709/220
`
`2/2001 Arbaugh etal. ............... 713/2
`.- 709/220
`5/2001 Frailong et al.
`
`5,557,748 A
`5,875,306 A *
`6,058,421 A *
`6,070,187 A *
`6,115,545 A *
`6,185,678 B1 *
`6,230,194 B1 *
`* cited by examiner
`Primary Examiner—Nabil El-Hady
`(74) Altorney, Agent, or Firm—Christopher Whewell
`(57)
`ABSTRACT
`
`This invention relates to a method of establishing an Internet
`Protocol network with several IP hosts and with an IP
`gateway for connecting the IP network to the Internet. The
`invention provides a method which no longer requires the
`knowledge of address mechanisms of the Internet protocol
`
`previously necessary for a successful establishment and thus
`
`(SL) Tint, C1ecceeeeteseeeteeneeneeees GO06F 15/177
`protects disturbances of errors during the establishment of
`(52) US. Chee 709/220; 709/221; 709/222;
`an Internet Protocol network.
`709/223; 709/224; 709/225
`(58) Field of Search oo...ee 709/220-225
`
`12 Claims, 4 Drawing Sheets
`
`IP-HOST_"NONAME*
` IP-HOST_"DHCP*
`
`
` ra “DNS
`
`
`CS
`
`asf
`1P-GATEWAY
`IP-ADRESSE. 10.0.0.254
`IP-NETZHASKE 255.0.0.0
`OHCP SERVER, ONS-SERVER
`
`SUCHE MsESHIDOE
`1P-HOST_"NONAME
`fe
`*ONS"
`IP-HOST
`POE IO 0.4
`IP-ADRESSE 10.0.0.3
`IP-ADRESSE. 10.0.0.2
`JP-NETZHASKE 255,0.0.0
`IP-NETZMASKE Re0.0.0
`IP-NETZMASKE 255.0.0.0
`IP-GATEWAY 10.0.0.254
`TP-GATEWAY 10.0.0.254
`TP-GATEWAY 10.0.0.254
`
`
`ONS-SERVER 10.0.0.254
`ONS-SERVER 10.0.0.254
`NS-SERVER 10,0.0.254
`
`
` ce
`
`oH SERVER, ONS-SERVER
`INTERNET-ZUGANG
`
`1
`
`APPLE 1010
`
`IP-GATEWAY
`IP-ADRESSE 10.0.0.254
`IP-NETZHASKE 255.0.0.0
`DHCP SERVER, ONS-SERVER
`ARBETTSPHASE DHCP
`varus
`IP-HOST
`"NONAME
`JP-ADRESSE 10.0.0.4
`IP-NETZMASKE 255.0.0.0
`
`IP-GATEWAY 10.0.0.1
`ONS-SERVER 10.0.0.1
`
`IP-H0s!
`IP-ADRESSE 10.i2
`9.0.0.0
`‘tra i0.0.1
`ONS-SERVER 10.0.0...
`KONFIGURATIIN DURCHCEFLRT
`LJ}FS)
`
`x
`
`'
`]P-ADRESSE 10.0.0.3
`IP-NETZMASKE 255.0.0.0
`
`TP-GATEWAY 10.0.0.1
`ONS-SERVER 10.0.0.1
`
`Ce
`
`
`
`APPLE 1010
`
`1
`
`

`

`US 6,560,642 B1
`
`U.S. Patent
`
`}8OH-d]
`
`May6, 2003
`
`Sheet 1 of 4
`
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`
`2
`
`

`

`U.S. Patent
`
`May6, 2003
`
`Sheet 2 of4
`
`IP-Host
`
`IP-Host
`
`255.0.0.0 ayDNS-Server10.0.0.4
`
`1P-Waske
`255.0.0.0 wayDNS-Server
`TP-Maske
`
`255.0.0.0 ayDNS-Server10.0.0.4
`IP-Maske
`
`IP-Adresse10.0.0.2
`
`
`[P-Adresse10.0.0.3
`
`[P-Adresse10.0.0.4
`
`10.0.0.4 DNS-Server
`
`US 6,560,642 B1
`
`
`
`IP-Gateway[P-Adresse10.0.0.1
`
`
`
`IP-Maske255.0.0.0
`
`FIGURE2 (PRIORART)
`
`3
`
`

`

`U.S. Patent
`
`May6, 2003
`
`Sheet 3 of4
`
`US 6,560,642 B1
`
`}80]]-d] idJHO.,
`
` SUPNON,,
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`Kenaye9-]J9A19S-SN
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`&ddanld
`
`4
`
`

`

`U.S. Patent
`
`May 6, 2003
`
`Sheet 4 of4
`
`US 6,560,642 BI
`
`IP-HOST “DNS*
`
`TP-HOST_ "DHCP"
`
`TP-HOST_*NONAME”
`
`
`
`“CAIEWAY
`IP-GATEWAY
`"PSEUDO" OHCP CLIENT
`SUCHE NACH DHCP-SERVEM
`
`IP-HOST “DNS*
`
`IP-HOST_“DHCP*
`
`TP-HOST_"NONAME*
`
` Ss
`
`IP-GATEWAY
`IP-ADRESSE 10.0.0,254
`IP-NETZMASKE 259.0.0.0
`DHCP SERVER, ONS-SERVER
`SUCHE ABGESCHIDSSEN
`IP-HOST_"NONAME”
`P-ADRESSE 10.0.0.4
`IP-NETZMASKE 255.0.0.0
`IP-GATEWAY 10.0.0.204
`ONS-SERVER 10.0.0.254
`
`IP-HOST "DNS"
`IP-ADRESSE 10.0.0.2
`IP-NETZMASKE 259.0.0.0
`IP-GATEWAY 10.0.0.254
`DNS-SERVER 10.0.0.254
`
`IP-HOST "DHCP"
`IP-ADRESSE 10.0.0. 3
`IP-NETZMASKE 295.0.0.0
`IP-GATEWAY 10.0.0.254
`ONS-SERVER 10.0.0.254
`
` (S444
`
`ONS-SERVER 10.0.0. (Se
`
`IP-GATEWAY
`IP-ADRESSE 10.0.0.254
`IP-NETZMASKE 255.0.0.0
`DHCP SERVER, DNS-SERVER
`ARBETTSPHASE DHCP
`a
`*NONAME
`1P-HOST
`IP-ADRESSE 10.0.0.4
`_P-NEVIMASE 2.0.0.0
`IP-GATEWAY 10.0.0.
`
`IP-GATEWAY
`IP-ADRESSE 10.0.0.
`IP-NETZMASKE 259.0.0.0
`DHCP SERVER, DNS-SERVER
`INTERNE T-ZUGANG
`
`IP-HOST *ONS*
`IP-ADRESSE 10.0.0.2
`IP-NETZMASKE 255.0.0.0
`IP-GATEWAY 10.0.0. 1
`INS-SERVER 0.0.0.1
`KONFIGURATION OURCHEFLHRT
`
`[P-HOST “DH(P"
`IP-ADRESSE 10.0.0.3
`IPETINE 25, 0.0.0
`1P-GATEWAY 10.0.0.1
`ONS-SERVER 10.0.0.1
`
`FIGURE 4
`
`5
`
`

`

`US 6,560,642 B1
`
`1
`METHODOF ESTABLISHING AN INTERNET
`PROTOCOL NETWORK UTILIZING IP
`GATEWAY THAT FUNCTIONSAS EITHER
`OR BOTH DHCP CLIENT AND DHCP
`SERVER
`
`FIELD OF THE INVENTION
`
`‘The present invention relates to a method of establishing _
`an Internet Protocol (“IP”) network with several IP hosts and
`with an IP gateway for connecting the IP network to the
`internet.
`
`BACKGROUND INFORMATION
`
`Explanation of the concepts used in conjunction with the
`invention:
`
`2
`Usually, additional IP addresses are entered into each IP
`host, converted into symbolic names,e.g., for the Domain
`Name Service (DNS in short) of the IP addresses and vice
`versa. The Domain NameService is practically indispens-
`able when working in the Internet.
`Another possibility for a new establishment of an IP
`network is that the user allocates an IP address and an IP
`network mask to only one IP host and uses this IP host for
`allocating IP addresses and IP network masks to additional
`IP hosts in the IP network. This is carried out by means of
`DHCP (DHCP: Abbreviation for Dynamic Host Configura-
`tion Protocol), which must be installed in the host. The
`DHCPis defined via RFC 2131 and RFC 2132 (See the
`explanations for "“RFC”). The IP host established manually
`by the user functions as DHCP server for the additional IP
`hosts, the DHCPclients. The allocation of the IP addresses
`to the IP hosts functioning as DHCPclients takes place from
`the DHCPserver, in which the user transfers IP addresses
`left on the DHCP server from the latter to the DHCP
`
`clients=IP hosts. This applies to the IP addresses of the IP
`hosts as well as to additional IP addresses, e.g., of a DNS
`server. The connection of the IP gatewayto the IP network
`nevertheless requires a manual establishment since the IP
`gateway can not beestablished from a DHCP server. Even
`in this method of establishing an IP network the user must
`know and have understood the address mechanism of the
`
`Internet protocol. Only the establishing cost for the IP hosts
`is eliminated.
`
`Therefore, a central disadvantage of the known methads
`is the fact that the user must know and have understood the
`
`address mechanismsofthe Internet protocol for a successful
`establishment of the IP network. Anyerrors in the estab-
`lishment can absolutely result in a disturbance in the entire
`IP network. The known methodsare therefore not suited for
`
`users without considerable knowledge ofthe Internet pro-
`tocol.
`
`The invention therefore has the basic problem of creating
`a methodof establishing an IP network with several IP hosts
`and with an IP gateway which method requires no knowl-
`edge of the address mechanismsof the Internet protocol for
`a successful establishment and therewith protects against
`disturbances, resulting from errors during the establishing.
`The solution of this problem makes use of the fact that all
`information necessary for establishing an IP network with
`Internet connection converge in the IP gateway.
`The inventionis also based on the concept, contrary to the
`traditional method, of at first not using a DHCPserver for
`the establishment but rather of allowing the IP gateway to
`find out in the non-established state as DHCP client whether
`
`there is a DHCPserverin the IP network already.If there is
`no DHCPserverthe IP gatewayis activated automatically as
`DHCPserver. The software (IP stack) for this is imple-
`mented in the firmware of the gateway so that the useris not
`burdened with the installation. The activated DHCP server
`allocates IP addresses and IP network masks to the IP hosts
`in a standard manner from a reserved address range so that
`the IP hosts and the IP gatewaycan exchangeIP data packets
`with cach other. Exclusively IP addresses which) are not
`given out in the Internet for IP hosts are normally located in
`the reserved address range.
`The problem is solved by the present invention.
`However, If the IP gateway discovers as DHCPclient that
`there is a DHCP server in the IP network already the IP
`gateway does not activate its own DHCPserver and logs off
`again in the found DHCPserver because an establishment
`and administration of the IP network in a traditional way
`with an IP host as DHCPserver is obviously intended.
`
`30
`
`40
`
`45
`
`55
`
`60
`
`65
`
`IP
`address
`
`IP
`network
`mask
`
`An IP address is a 32-bit number which is regularly
`represented with four number separated bydots in the so-called
`“dotted notation”. Each of these numbers describes a complete
`bite 8 bits wide. The 32-bit number contains a network address
`as well as a host address which are held apart from one another
`by the IP network mask (See “IP network mask” for
`explanation).
`An IP network mask is a 32-bit number represented
`analogously to an IP address. IL keeps Lhe network address and
`the host address in the IP address apart from one another by
`logical AND operation, that is, all 1 bits of the network
`mask define the part of the IP address which belongs to the
`network address. (If the network mask is, e.g., 255.0.0.0; 255 =
`128 + 644+ 324+164+8+4+2+1 <4 decimal =
`111111411 binary, the 8 front bits are set. If the network
`mask 255.0.0.0 is nowlogically “AND”linked, ¢.g., with an
`IP address 10.0.0.4, the result is 10.0.0.0. This result is then the
`network address whereas the host address is the entire IP address
`10.0.0.4. The mode of expression: Host 0.0.4 in the network
`10.0.0.0 is also customary.
`An IP stack is a method which makes possible the
`processing of IP data packets according to TCP/IP-based
`protocols (TCP/IP: Abbreviation for Transmission Control
`Protocol/Internet Protocol) in a computer. The open standards -
`also called RFC (RFC: Abbreviation for “requests for
`comments”) - containall definitions of the TCP/IP-based
`protocols. The RFC’s are numbered consecutively and are
`available [ree of charge, e.g., via the Internet. RI'C’s
`are never changed. There are at the most supplementary
`or replacing RFC’s.
`An IP host is a computer in which an IP stack has been
`installed.
`An IP gatewayis a computer which can execute the
`switching of IP data packets between a computer and a network,
`here the Internet. This computer is provided with an IP stack so
`that it can convert the IP data packets from one transmission
`medium to another transmission medium, e.g., from a LAN
`(LAN:Abbreviation for Local Area Network) to an WAN
`(WAN:Abbreviation for Wide Area Network).
`An IP network consists of several IP hosts and an IP
`IP
`network gateway linked to each other for a data transmission.
`
`stack
`
`IP
`host
`IP
`gateway
`
`Several possibilities are known [rom thestate of the art for
`establishing an IP network:
`The user manually allocates an IP address and an IP
`network mask to each IP host
`in the IP network. Each
`additional IP host which is to be tied into the IP network
`therefore requires an additional establishing cost. The work-
`ing cost includes the fact that the user must know and have
`understood the address mechanisms oftheInternet protocol
`since an erroneous establishment of individual IP hosts can
`
`absolutely result in a disturbance in the entire IP network. If
`the user desires to connect the IP network to the Internet he
`requires an IP gateway for this whose IP address must also
`be entered manually in each IP host of the IP network.
`
`6
`
`

`

`US 6,560,642 B1
`
`4
`in the address range reserved to this end. A further central
`advantage is the fact
`that misconfigurations are avoided
`since all IP addresses and IP network masks for further IP
`
`hosts in the IP network are centrally given out by the IP
`gateway.
`The methodis designed so that it can also be used without
`problems in already existing IP networks for their
`re-establishment.
`
`10
`
`FIGS. 1 to 4 are referred to in order to explain the state
`of the art and the invention.
`
`3
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`In the annexed drawings:
`FIG. 1 shows the components of an IP network according
`to the priorart;
`FIG. 2 showsthe components of an IP network according
`to the priorart;
`FIG. 3 shows a non-established IP network suitable for
`use in accordance with the present
`FIG. 4 shows an IP network suitablefor use in accordance
`
`with the present invention.
`DETAILED DESCRIPTION
`
`In an embodiment of the invention an access to the
`
`15
`
`Internet for the individual IP hosts can be prepared in that
`after the allocation of IP addresses and IP network masksto
`at least one IP host a program for configuring the Internet
`accessis started. The program starts a broadcastcall of the
`IP host to an address, reserved for the broadcastcall, of the _
`IP gateway functioning as DHCPserver. The configuration ~
`programallocates an [P network mask and IP addressto the
`IP gateway from the address range reserved for this under
`which the gateway is detectable if a non-configured IP
`gateway with active DHCPserveris presentat the reserved
`address for the broadcast call.
`The establishment of the Internet access for the entire IP
`
`network via only oneIP host by meansof the configuration
`program takes place as follows:
`The IP host selected for the configuration determines by
`means of the locality criterion whether an IP address of
`another IP host in another IP network(target IP address) is
`present with which one of the IP hosts of the local IP
`network would like to make contact. ‘The target IP address
`can be accessible, ¢.g., via an Internet provider or bydirect
`connection to the other IP network. It sends all IP packets
`determined for IP addresses which are not located in the
`
`30
`
`35
`
`In the traditional establishing of an IP network several
`individual configurations are necessary in the IP hosts and
`the IP gateway in a certain sequence before IP packets can
`be transmitted within the IP network and, if necessary, to
`another transmission medium, e.g.,
`the Internet. FIG. 1
`shows the components of an IP network which the user of
`traditional methods must configure.
`FIG. 2 showsthe typical scope of a ready-configured IP
`network with connection to the Internet. In addition to the IP
`
`address and the IP network mask for the particular IP host
`the IP address of the IP gateway must be manually entered
`in each IP hostof the IP network for the Internet connection.
`In addition, the address for the domain name service (DNS
`in short) must be entered in each IP host. The DNS converts
`IP addresses into symbolic names andvice versa.
`FIG. 3 shows a non-established IP network, that is, the
`initial situation for
`the method in accordance with the
`invention. The symbolic names of the IP hosts “DNS,
`DHCP, NoName”are entered manuallyby the user. Usually,
`a modernIP stack installed in each of the connected IP hosts
`provides an inquiry to the user about such a symbolic name
`during the installation. In addition, the IP stacks can operate
`as a DHCPclient. The IP gateway functions for the con-
`nection to the Internet.
`FIG.4 illustrates that, counter to the traditional method,
`at first no DHCPserver is used for the establishment but
`
`rather the IP gatewayfinds out in the non-established state
`as DHCPclient whether there is a DHCP server in the IP
`
`40
`
`45
`
`network already(first line of FIG. 4). If there is no DHCP
`server the IP gateway is automatically activated as a DHCP
`server under the IP address 10.0.0.254 with the network
`mask 225.0.0.0 and assures that
`in the future all DNS
`inquiries are passed on to a DNS server. As regardsthe local
`IP network with its IP hosts the IP gateway acts as a DNS
`server; as regards the Internet the IP gatewayacts as a DNS
`client which routs onward the DNS inquiries of the IP hosts
`of the local IP network. The professional terminologystates
`that the IP gateway establishes a DNS forwarder (second
`line of FIG. 4).
`The activated DHCP server allocates IP addresses
`10.0.0.2, 10.0.0.3, 10.0.0.4 and IP network masks 225.0.0.0
`to the IP hosts “DNS, DHCP, NoName”according to the
`standard from a reserved address range so that the IP hosts
`5 and the IP gateway can exchange [P data packets among
`each other.
`
`60
`
`65
`
`In addition, the access to the Internet for the IP hosts
`“DNS, DHCP, NoName”is prepared in that after the allo-
`cation of the IP addresses and IP network masks a program
`for configuring the Internet accessis started, e.g., on the IP
`host “DNS”. The program starts a broadcast call of the IP
`host “DNS” to an address of the IP gateway functioning as
`DHCPserver which address is reserved for the. broadcast
`
`call. The configuration program allocates the IP network
`mask 255.0.0.0 and IP address 10.0.0.1 from the address
`range reserved for this purpose to the IP gateway under
`which the gateway is detectable by the IP hosts for the
`
`local IP network of the IP host selected for the configuration
`to its responsible default IP gateway. The IP gateway must
`now decide using the target IP address where it must
`retransmit the IP packetto. ‘To this end there is an IP routing
`table in the IP gateway which defines a linking of IP
`addresses and targets. ‘The configuration tool nowenters a
`default route in the IP gateway which route transfers all IP
`packets with target IP addresses outside of the local IP
`network to an Internet provider. This takes place, e.g., in an
`ISDN dial connection to the Internet provider by means of
`the automatic design of the default route as soon as an IP
`packetis to be transferred to the Internet providerin case this
`connection is not already present.
`The user receives the data necessary for the configuration,
`including, among other things, a DNS IP address, from his
`Internet provider. The access to the Internet via the Internet
`provider functions thereby with an address translation tech-
`nology for IP addresses (knownas IP masquerading) so that
`the IP addresses given out internally in the IP network are
`not passed on to the provider andinto the Internet. As soon
`as the Internet access has been configured via the gateway,
`accesses to the Internet via the IP gateway are possible by
`any IP hosts in the IP network. The IP gateway administers
`thereby the IP masquerading out of and into the reserved
`address range as well as for inquiries for the conversion of
`symbolic names into IP addresses and vice versa (DNS).
`‘The main advantage of the invention is the fact that the
`expense for establishmentis significantly reduced sinceall
`IP addresses and IP network masks in the IP gateway
`necessaryfor the operation of the IP network have beenfiled
`
`7
`
`

`

`US 6,560,642 B1
`
`6
`wherein said IP gateway includes a meansfor determining
`whether a DHCPserveris present in said network.
`6. An IP network according to claim 5 wherein said IP
`gateway further includes a means for activating itself as
`DHCPserver.
`
`7. An IP network according to claim 5 wherein an IP
`gateway is functioning as DHCP server, and further com-
`prising a means for allocating an IP address and an IP
`network mask to each IP host in said network.
`
`8. An IP Network according to claim 7 wherein said IP
`address and said IP network mask are selected from a
`
`10
`
`15
`
`5
`Internet access. A prerequisite for this is that the IP gateway
`has not yet been configured and that an active DHCP server
`is present(third line of FIG. 4).
`After the conclusion of the complete configuration the IP
`network like the one in FIG. 4, line four, is present.
`Whatis claimedis:
`1. Amethod of establishing an IP network with several IP
`hosts and with an IP gateway for connecting the IP network
`to the Internet, characterized in that:
`An IP stack is installed in each IP host which stack can
`function as a DHCPclient,
`reserved address range.
`An IP stackis installed in the IP gateway which stack can
`9. Aprocess for establishing an IP network comprising the
`function both as a DHCPclient and as a DHCPserver,
`steps of:
`After having been activated, the IP gateway functions at
`first as a DHCP client and checks whether a DHCP
`a) providing a plurality of IP hosts, wherein each IP host
`includesafirst IP stack that is capable of functioning as
`server is present in the IP network, and
`a DHCPclient;
`If no DHCPserveris presentin the IP network the DHCP
`b) providing an IP gateway connected to said hosts,
`server in the IP gatewayactivates itself and allocates IP
`addresses and IP network masks to each activated IP 2
`wherein said gatewayincludes a secondIP stack that is
`capable of functioning as either a DHCPclient, or as a
`host from a reserved address range.
`DHCPserver;
`2. The method according to claim 1, characterized in that
`the IP address allocated to cach IP host is routed onward to
`c) causing said IP gateway to detect whether a DHCP
`server is present in said network;
`d) causing said IP gateway to become active as a DHCP
`server in cases when no DHCPserveris detected; and
`e) causing said IP gatewayto allocate IP addresses and IP
`network masks to each IP host in said network.
`
`the Internet by means of known addresstranslation tech-
`nologies.
`3. A method of establishing an IP network with several IP
`hosts and with an IP gateway for connecting the IP network
`to the Internet, characterized in that:
`An IP stack is installed in each IP host which stack can
`10. A process for establishing an IP network comprising
`function as a DHCPclient,
`the steps of:
`An IPstackis installed in the IP gateway which stack can
`a) providing a plurality of IP hosts, wherein each IP host
`function both as a DHCPclient and as a DHCPserver,
`includesafirst IP stack that is capable of functioning as
`a DHCPclient;
`After having been activated, the IP gateway functions at
`first as a DHCP client and checks whether a DHCP
`b) providing an IP gateway connected to said hosts,
`server is present in the IP network, and
`wherein said gatewayincludes a secondIP stack that is
`If n0 DHCPserveris presentin the IP network the DHCP
`capable of functioning as either a DHCPclient, or as a
`DHCPserver;
`server in the IP gateway activates itself and allocates IP
`addresses and IP network masks to cach activated IP
`
`35
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`host from a reserved address range and further charac-
`terized in that after the allocation of the IP addresses
`and IP network masks a program for configuring the
`Internet access is started on at least one IP host which
`program starts a broadcast call of the IP host to an
`address, reserved for the broadcast call, of the IP
`gateway functioning as DHCP server and that
`the
`configuration program allocates an IP address and an IP
`network mask fromthe reserved address range to the IP
`gateway under which the gateway can be detected if a
`non-configured IP gatewaywith active DHCPserveris
`present at the reserved address.
`4. The method according to claim 3, characterized in that
`the IP address allocated to each IP host is routed onward to
`the Internet by means of known address translation tech-
`nologies.
`5. An IP network capable of being connected to the
`Internet, comprising:
`11. The process of claim 10 wherein the IP address
`allocated to said IP hosts is routed to the Internet by means
`a) a plurality of IP host computers each havingafirst IP
`stack installed therein, wherein said first IP stack is
`of known addresstranslation technologies.
`capable of functioning as a DHCPclient;
`12. The process of claim 9 wherein the IP address
`allocated to said IP hosts is routed to the Internet by means
`b) at
`least one IP gateway, having a second IP stack
`of known addresstranslation technologies.
`installed therein, wherein said second IP stack is
`capable of functioning as either or both a DHCPclient
`and as a DHCPserver,
`
`c) causing said IP gateway to detect whether a DHCP
`server is present in said network;
`d) causing said IP gateway to become active as a DHCP
`server in cases when no DHCPserveris detected;
`e) causing said IP gatewayto allocate IP addresses and IP
`network masks to each IP host in said network; and
`f) initiating a program for configuring Internet access on
`at least one IP host,
`wherein said program starts a broadcastcall of the IP host to
`an address, said address having been previouslyreserved for
`such a broadcastcall, to an addressof the IP gateway (when
`said IP gatewayis functioning in its DHCP server capacity),
`and wherein said programallocates an IP address and an IP
`network mask from a reserved address range to the IP
`gateway through which a non-configured IP gateway may be
`detected when an active DHCP server is present at
`the
`reserved address.
`
`40
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`45
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`50
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`60
`
`ek e
`
`OF
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`*
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`8
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`