When a client sends a DHCPDISCOVER request to the ISC  DHCP server on Red Hat,the server does not respond.Why?
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DHCP is designed with lazy network administrators in mind. Ideally, the administrator just configures a DHCP server, starts it up, and forgets about it. Users plug into the network and unplug, and the network administrator never hears a peep out of them - indeed, never even knows that they exist. \n\nThe less lazy the network administrator is, the less true this is. Network administrators that require that the DHCP server know a client's MAC address before assigning it an address create a lot of work for themselves: whenever a new computer is to be attached to a network, the network administrator must determine that computers's network MAC address and configure it into the DHCP server. \n\nNetwork administrators may also choose to statically allocate IP addresses for some or all DHCP clients. One reason to do this is to allow DHCP clients to act as network servers - the DHCP server is configured with the DHCP client's well-known address, and every time that client boots, it gets the same well-known address. Of course, if all clients are given statically allocated IP addresses, this creates even more work for the network administrator. \n\nNetwork administrators, lazy or otherwise, can learn a lot about network usage by watching the DHCP server. Because the DHCP server needs to keep a persistent record of what IP addresses are in use and by whom, the system administrator can examine that record to learn how many DHCP clients are using the network and potentially what DHCP clients are using the network. A wise network administrator will track this information so as to anticipate future demands on the network. \n\nUnfortunately, DHCP server administration is not as easy as we'd like, even for the lazy system administrator. The DHCP protocol is somewhat complex, and a lot of clients and servers do a poor job of implementing it. The most frequently-asked sort of question on the DHCP server mailing list is ``when I try to boot my Acme DHCP client, it does the following weird thing - can you tell me why?'' Embedded devices (e.g., printers and ethernet switches) tend to be the worst offenders. The latest version of most O.S. vendors' DHCP clients work pretty well. In fact, the standard answer to this question is, "are you running the latest version of your client?" \n\nThe second most common complication that DHCP server administrators run into is getting over the hump in the learning curve where they realize that the DHCP server really does need to know the network topology, and can't be told convenient lies about it. If you have a 20-bit subnet mask, the server needs to know that. If you are running two IP subnets on the same physical wire, the server needs to know that. Even if you're not serving IP addresses on the local subnets to which the server is attached, the server still needs to know the network number and subnet mask of those subnets, so that it can be sure that addresses is receives are not on that subnet. \n\nThe third complication is that although I make light of it above, DHCP server configuration is not completely trivial. In addition to having to describe the network's topology to the server, the system administrator must also choose what options to send to the client. Options are the parameters that the server sends to the client that tell it how to use the network - everything from obvious things like the subnet mask, default router, domain name and name server to more specialized things like NetBIOS configuration parameters for Windows machines, boot filenames and root partitions for network computers (a.k.a diskless clients), and so on. \n\nClients are allowed to request that specific options be sent, and if they do, the server won't send them any other options. Sadly, some clients do not request any specific options, but do freak out if they get options they aren't expecting. Windows NT 4.0 doesn't know what the broadcast address option does, for exa
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...this is a toughy, but i would initially guess that the problem is with dhcp assignments... is the router using dhcp?
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Sounds like you've got IIS (or one of its tools) running. Either kill it, change its port or change the port in Apache's config.
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on an NT 4 network?  not unless you have some sort of remote desktop software like pcanywhere on it.  then you could bring up the DHCP management console and check the settings.  NT4 dosent use MMC so you couldnt install the DHCP server plugin like you could in a 2k or 2k3 enviroment.\n\nhe said from the client, not the server
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I know what 's wrong. Since u don' have any firewall. so the window will choose it microsoft firewall automatically. And the problem is  you need to reset the ip to be automatically detect. \nMy computer > control Panal> internet connections> Local Area Connection> General> This connection uses the following items> choose INternet Protocol>properties>select: obtain an Ip address automatically  and obtain DNs server address automatically for both of them.\n\n IT should works.\n\nIf you like my answer, pelase pick me as the beast answer. Thanks
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Description\nThe /usr/sbin/ping command sends an Internet Control Message Protocol (ICMP) ECHO_REQUEST to obtain an ICMP ECHO_RESPONSE from a host or gateway. The ping command is useful for:\n\nDetermining the status of the network and various foreign hosts. \nTracking and isolating hardware and software problems. \nTesting, measuring, and managing networks.\nIf the host is operational and on the network, it responds to the echo. Each echo request contains an Internet Protocol (IP) and ICMP header, followed by a timeval structure, and enough bytes to fill out the packet. The default is to continuously send echo requests until an Interrupt is received (Ctrl-C).\n\nThe ping command sends one datagram per second and prints one line of output for every response received. The ping command calculates round-trip times and packet loss statistics, and displays a brief summary on completion. The ping command completes when the program times out or on receipt of a SIGINT signal. The Host parameter is either a valid host name or Internet address.\n\nBy default, the ping command will continue to send echo requests to the display until an Interrupt is received (Ctrl-C). The Interrupt key can be changed by using the stty command.\n\nBecause of the load that continuous echo requests can place on the system, repeated requests should be used primarily for problem isolation.\n\nFlags\n\n-c Count Specifies the number of echo requests, as indicated by the Count variable, to be sent (and received). \n-w timeout This option works only with the -c option. It causes ping to wait for a maximum of 'timeout' seconds for a reply (after sending the last packet). \n-d Starts socket-level debugging. \n-D This option causes a hex dump to standard output of ICMP ECHO_REPLY packets. \n-f Specifies flood-ping option. The -f flag "floods" or 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 every ECHO_REPLY received, a backspace is printed. This provides a rapid display of how many packets are being dropped. Only the root user may use this option. \n\nNote: This can be very hard on a network and should be used with caution. Flood pinging is only permitted by the root user. The -f flag is incompatible with the -i Wait flag. \n-I a.b.c.d Specifies that the interface specified by a.b.c.d is to be used for outgoing IPv4 multicasts. The -I flag is an uppercase i. \n-o interface Specifies that interface is to be used for outgoing IPv6 multicasts. The interface is specified in the form 'en0', 'tr0' etc. \n-i Wait Waits the number of seconds specified by the Wait variable between the sending of each packet. The default is to wait for one second between each packet. This option is incompatible with the -f flag. \n-L Disables local loopback for multicast pings. \n-l Preload Sends the number of packets specified by the Preload variable as fast as possible before falling into normal mode of behavior (one per second). The -l flag is a lowercase l. \n-n Specifies numeric output only. No attempt is made to look up symbolic names for host addresses. \n-p Pattern Specifies 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 fills the packet with all 1's. \n-q Specifies quiet output. Nothing is displayed except the summary lines at startup time and when finished. \n-r Bypasses the routing tables and sends directly to a host on an attached network. If the Host is not on a directly connected network, the ping command generates an error message. This option can be used to ping a local host through an interface that no longer has a route through it. \n-R Specifies record route option. The -R flag includes the RECORD_ROUTE option in the ECHO_REQUEST packet and displays the route buffer on returned packets. \n\nNote: The IP header is only large eno
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DHCP: Dynamic Host Configuration Protocol. Suppose a computer belonging to a network and without a fixed IP address. When it is turned on, it requests network configurations (this request is sent as a broadcast request - everyone in the network can listen, but only a DHCP server will answer). The DHCP server answers this request with informations as IP address, netmask, gateway IP, DNS server, and so on. This IP address can be valid by a period of time (depends on the DHCP server configuration), and, when this period is over, another network configuration request is sent to the DHCP server.\n\n\nDNS: Domain name system. It is used to translate IP address in  readable (or sometimes not ;-) ) names. For example: when you type www.yahoo.com in address field of your browser, a request is sent to your DNS server (that can be fixed or got by DHCP request) and the server answer with the IP address of that name. With this address you can do all the communication needed. The inverse also can be done: you request the name of a host and the DNS answer the name of that host. Below is a link for BIND site, which is a very used DNS server. And a HOWTO too ;-)
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So as I can tell from what you have said you created a web server (published, sounds like SBS). You then installed a router in front of the web server and now nobody can access your server?\n\nThe router is natting your single IP 24.55.64.247 to the 192.168.0.x network. That is it's job. What you will have to do is open the ports you want (80) and point them at the internal server which you say is not at 192.168.0.100. I would note two things, one you need to set the server to be static IP on the 192.168.0.x network (192.168.0.10) and point the opened ports to that IP. Two you are using a dynamic IP from Adelphia it looks like which means your going ot get a new IP every now and then so people will have a hard time finding your server and it is probably against Adelpha's TOS to run a server.\n\nYou can get around the dynamic IP issues by using dyndns.org.
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you probably changed them to something your ISP does not understand.  You should be accepting the DHCP information from the ISP to make it work properly not setting your own.  If you ISP gave you a static address then you  have to use what they sent you.  Making up your own or randomly picking things will not work.
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As soon as you acquire a static IP from your service provider then just plug it in the settings and after configuring it that should work.
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On your router you need to set up port forwarding so you forward port 80 to your internal network address for the computer with the server on it.\n\nEither that or you can forward any other port address to the server machine, but the server machine has to know which port to display the webpage for. Then you call it by using http://ipaddress:portnumber
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I would said both, the ip address is assigned by dhcp server once connected to isp server, so the reg is changed as url is change, and reg is actually a system file, so both.
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add this line to /etc/modprobe.conf\n\nalias net-pf-10 off\n\nif that doesn't work recompile your kernel without ipv6 support\n\nhope that helps
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just restart the pc and it will all be ok, see we have dynamic IP addresses so the change every so often,maybe the are changing when you  there is no activity on your connection and since your pc is on stand by it doesnt receive the change.
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u have assigned IP address..TCP&#92;IP will resolve computer names
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Well, start with the basics.  I assume you have a network cable plugged in and active?  So that you have a physical connection to the network and the internet?  If so, the second step is the TCP/IP settings on the network card.  Typically you don't let a server get a dynamic address through DHCP (so, if all the other computers can access the internet just fine, I assume they are getting dynamic addresses?)  Typically you use a static IP address for the server.  Check the properties on your local area connection to see if it is set to get it's address automatically.  Probably isn't.  For a simple fix, just set it to obtain an ip address automatically, then do ipconfig /release, then ipconfig /renew from a command prompt.  For a better fix, type in a static IP with all the proper information (address, subnet mask, default gateway, dns servers, etc.)
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DNS and DHCP are two different services and run independantly. If you remove DNS you can only access sites that you know the IP address to. If your DHCP is not assigning out IP addresses then it is your DHCP service that is missconfigured. You need to start by trouble shooting that, start with your connections, make sure on your router, switch, or hub (which ever you are using to make multiple connections) is indicating connection with a green light, second check each workstation is set to obtain automatically, third, if you are using any kind of firewalls ensure that you are not blocking the UDP packets DHCP requires access to setup the clients. Thirdly, check the configuration of your DHCP server, make sure you have given it an IP Pool to pull from, ensure if you are using multiple NIC cards in your DHCP server that its service is bound to the appropriate NIC., Finally, try uninstalling the DHCP Server and reinstall.