Ubuntu Networking :: DHCP Server Not Handing Out Addresses?
Oct 20, 2010
I have a MacBook Pro running VirtualBox with Ubuntu 10.10 as a guest. I am trying to run a DHCP server from within the Ubuntu VM. I need to do this in order to run a multicast utility. On a stand alone machine running Fedcora I have this working without fail but within the Ubuntu VM I am having troubles. The DHCP server is starting okay, but when I use a cross over cable connected to a device the device does not ever get an address.I have eth1 bound to my ethernet jack where I am trying to source the addresses, and eth2 bound to my airport which is disabled unless I need internet access.Here is my DHCP.conf file
Ubuntu LTS 8.04 + DHCP. Works fine except for fixed addresses. I mean all devices which need to get fixed IP according to their MACs don't get them and keep to receive random IPs from the range (although almost everytime all machines receive the same IP they got from DHCP for the first time).
The following config was created by Webmin interface.
At the one of the ubuntu forums i was advised to carry host description out of the subnet description.
I am using Ubuntu Server and would like to recieve an email once a day listing mac address's that have requested an ip address that are not in my list of known mac address's.
lookup=`grep $mac /root/dhcp.macs`
#This does not work as the first entry mac1 will be okay but mac2 and mac3 will not
#It will try to use mac2 as the file to look in which won't exist
#I need to make it loop through for each line of the variable and add that to the lookup value diff $mac $lookup
#I think this should differentiate known from unknown if i can get a lookup value
A quick rundown of my equipment and plan for this particular machine.
SOYO P4I845PEISA Motherboard Intel Pentium 4 2.0GHz Processor 512MB DDR333 RAM ATI Radeon 8500 128mb AGP Video Card Using onboard AC'97 Audio and Davicom NIC Linksys BEFSR81 Wired Router
I am setting up a multiboot system with several OS's, multiple versions of Windows & several Linux distros. The main point of it all is just to have a system where I can load up a given version of Windows or Distro of Linux if I need to test something or show someone how something works.
The Problem: 5 versions of Windows installed, all hardware configured and functioning properly (including NIC) All Windows versions obtain DHCP IP addy with no problems.
Installed Red Hat Linux 9 (first of my linux distros) and it autoconfigured all of my hardware and has no problem getting an IP address.
Installed Fedora 8 and it could not obtain an IP address. I fiddled around with the network settings changing this and that, covered all of the options, and it had no effect. By this time I was irritated, so I just formatted and reinstalled the whole thing, which had no effect and resulted in the same problem. I decided to try it again, this time turning off my sound card and nic for the initial installation. After the initial install, I turned on the sound card and booted up to install it, then restarted, turning on the nic to install it. Fedora installed them both, and managed to get an IP address from my router.
I looked at the ifcfg-eth0 file and the only thing that was different from the previous installs was that a line reading "type=ethernet" (I believe thats what it said) was not there in the working install and had been before.
Puzzling and irritating, but Fedora was now working so I moved to the next distro on my list.
openSUSE 11.0 First install I tried the same thing I did with Fedora (turning off the NIC which did not work like it did in Fedora) Second install, left all of my hardware enabled, and made it to the part where it asks to verify your internet connection. I clicked Test, and got this error:
Opening of Connection eth0 device: Davicom Semiconductor, Inc. 21x4x DEC-Tulip Compatible 10/100 Ethernet (rev 40) DHCP Client is already running on eth0
I finished the install, and then got on another machine and I searched the net for this error, but could find nothing that specifically applied to my problem. I played around with the network settings, tried a couple of things that I had come across in my search (changed between tulip and dmfe, checked the box for "Request Broadcast Response", ran "service network restart" in Terminal) none of these had any effect.
The most irritating thing about this is that RHL9 had no problem with this whatsoever and it is badly dated, and the much newer distros are choking on it.
I'm new to Centos 5 (and Linux) and, after installing Centos, I configured Samba, Apche, ... w/o problems (through interactive interface). My problem is tha t I need to use DHCP (all our clients use dynamic IP addresses for the ease) but I don't find dhcpd ... nor the sample config file(s).
Note : the new server I intend to use is actually connected on a LAN with an 'old' DHCP server (still under W2K server), is this the reason why I can't find/activate dhcp on my new machine ???
This works perfectly, however when I try to add a second client this way it doesnt. I tried to add the above code multiple times as a whole (2 times the above code) but that doesnt work. I also tried to just add more lines under host apex but this also doesnt work.
So my question is: How do I add more of this mac related IP adress assignments in the dhcp.conf?
I am trying to configure my IPv6 network. My computers are behind a Fedora gateway IPv6-configured, which is working great. But for computers inside my network, it seems I am getting only internal addresses from DHCP. Here is my ifconfig for an internal computer:
Back in April I set up a Ubuntu DHCP server and a multiple VLAN network [URL] to migrate our various servers, workstations, etc off the 192.168.1.1 /24 network that everything was on because we where running out of address space. I built out the new network and everything worked great except our AD server would never get an IP address from the DHCP server (static reservation) and even if I set the IP statically on the AD server it couldn't ping the gateway and noone could log in. After several attempts to resolve this, including bringing in outside help, we where never able to figure out what the problem was.
Now 6 months later I have time to revisit the issue without effecting the live network. I used Acronis and imaged the AD server last Friday, cloned it on to another box with the same hardware, and put it up on the new network that's been sitting unused for the last 6 months. Today when I statically set the IP on the AD server (which is what I want) it connects and I can ping it's gateway 192.168.1.1 and all the way across vlans to a test sales agent workstation at 192.168.8.xxx on vlan 800 but only if I statically assign the agents station an IP address. When I try to get an IP address via DHCP it fails as destination unreachable. Nothing has changed in the last 6 months on the DHCP server but now it for some reason can't ping its default gateway 192.168.1.1. All of the config files are the same as they where left from the post linked above aside from the vlan id's used where changed from 1's to 100's (i.e. vlan 3 is now vlan 300) /etc/network/interfaces
Code:
auto lo iface lo inet loopback auto vlan100 iface vlan100 inet static
[code]....
why it can't reach the gateway, when I do a tcpdump I can see the DHCP requests come in on eth0 but the server never responds and I'm pretty sure its because it isn't "seeing" them since it thinks there isn't a network connection but I don't know how to trouble shoot to find out where the problem lies.
Back in April I set up a Ubuntu DHCP server and a multiple VLAN network [URL] to migrate our various servers, workstations, etc off the 192.168.1.1 /24 network that everything was on because we where running out of address space. I built out the new network and everything worked great except our AD server would never get an IP address from the DHCP server (static reservation) and even if I set the IP statically on the AD server it couldn't ping the gateway and noone could log in. After several attempts to resolve this, including bringing in outside help, we where never able to figure out what the problem was.
Now 6 months later I have time to revisit the issue without effecting the live network. I used Acronis and imaged the AD server last Friday, cloned it on to another box with the same hardware, and put it up on the new network that's been sitting unused for the last 6 months. Today when I statically set the IP on the AD server (which is what I want) it connects and I can ping it's gateway 192.168.1.1 and all the way across vlans to a test sales agent workstation at 192.168.8.xxx on vlan 800 but only if I statically assign the agents station an IP address.
When I try to get an IP address via DHCP it fails as destination unreachable. Nothing has changed in the last 6 months on the DHCP server but now it for some reason can't ping its default gateway 192.168.1.1. All of the config files are the same as they where left from the post linked above aside from the vlan id's used where changed from 1's to 100's (i.e. vlan 3 is now vlan 300) /etc/network/interfaces
Code:
auto lo iface lo inet loopback auto vlan100
[code]....
why it can't reach the gateway, when I do a tcpdump I can see the DHCP requests come in on eth0 but the server never responds and I'm pretty sure its because it isn't "seeing" them since it thinks there isn't a network connection but I don't know how to trouble shoot to find out where the problem lies.
Currently I have my eth0 interface getting a DHCP address but at times the DHCP server will not be reachable. Sooo what I would like my server to do is if it cannot find a DHCP server assign a static address to eth0. Then start the DHCP service so it can then dish out some addresses.How can I do this? Surely it is possible
I am puzzled with trying to configure a linux (openSUSE) client to dhcp to eBox DHCP server. I am using dhclient to lease an IP address with dhclient eth0 -s 10.45.48.108 and get a response
openSUSE11232CL1 dhclient: DHCPDISCOVER on eth0 to 10.45.48.108 port 67 interval 4 openSUSE11232CL1 dhclient: DHCPOFFER from 10.45.48.108 openSUSE11232CL1 dhclient: DHCPREQUEST on eth0 to 10.45.48.108 port 67 openSUSE11232CL1 dhclient: send_packet: Network is unreachable openSUSE11232CL1 dhclient: send_packet: please consult README file regarding broadcast address.
The server reports eBox141 dhcpd: DHCPDISCOVER from 00:0c:29:3e:57:a3 (openSUSE11232CL1.domain.net) via eth0 eBox141 dhcpd: DHCPOFFER on 10.45.200.2 to 00:0c:29:3e:57:a3 (openSUSE11232CL1.domain.net) via eth0
I interpret this as the server receives the request and the client accepting it but the lease does not last long and the connection breaks. what this could be and why the connection breaks? Or my undestanding is totally wrong on how it works and should work? And BTW, where is that README file that's referenced in the message I receive on the client?
In school, use SUSE Server and made it by DHCP but in my hand I changed many rules. All are OK at the start but now they requested that they who are principal, and vice principals are want to use the Internet without filtering.
So I've made new rules by using Webmin software to control the SUSE Server. 1st I've gave static IP from LAN x.x.x.40 to x.x.x.45. 2nd IP is x.x.x.12 to x.x.x.15.
At First, there's nothing happen but now I've got problems because Server gave DHCP so that Server gives IP itself and conflict with static IPs. And also I can't find in Webmin software how to disable the DHCP Assign.
I have two nagging problems on one network which I do not have on another elsewhere, both using uptodate Debian servers. The server is on the private subnet behind a router/adsl modem. The symptoms of the one which does not work
1) Users cannot access their web site from lan. If they try, they get to the router web interface, same as if they entered http:10.0.0.138 which is the router's lan address.
2) Users cannot access smtp or pop3 service using the domain name, they can access it only using the servers LAN address.
I fear that I might have not set up the router properly because appart from that the two servers are almost identical but I do not know where I might have made an error.
I installed fedora lastnight, but any addresses I type in the field is returning server error, but if I type the IP address it will work, I reinstalled Fedora 11 about 3 times, samething.
I have an embedded device for which I've created an html configuration page. This page allows you to set static IPs, dhcp, and can scan for wireless devices.My problem is that in order to access the device it requires that it runs as a dhcp server otherwise people are not assigned an IP and so can not access the embedded devices static IP. (This config page is for the laymen and so they are not the type who are able to set up their own static IPs). One of the potential options is to have the device connect to the network on eth0 acting as a dhcp client. However this prevents me from running a dhcp server.One solution I can think of is running a dhcp server only if it doesn't detect another dhcp server running on the network.
I have 2 Ethernet connections, one (eth0) for the internet which gets set with dhcp, and one (eth1) for my internal network on which I have dhcp3-server running. I set eth1 to use static IP in interfaces, but every time I reset the network, it is fine for a couple of minutes, and switches over do being served by my own dhcp server on the same machine. (the interfaces file clearly says "iface eth1 inet static")
I reinstalled Ubuntu server, now, as always I have to start off with 8.04 then upgrade to 10.04, and I've never had a problem with this before on this machine or any other for that matter. The problem is, this time I have installed and Ubuntu installer cannot see a DHCP, I go a head and install anyway and fire up Ubuntu and there is no internet access, I have two network cards plugged in, when I type in ifconfig it shows only lo and no network cards, and yet when I check lspci ot shows both network cards are there and when either are plugger in it shows connection on both the connector at the stack end and on the router.
i have a homework where i have to set up a dhcp server on linux. I am using ubuntu. I tried following: [URL] However after running "sudo apt-get install dhcp3-server" the file "/etc/default/dhcp3-server" does not appear.
I'm trying to get a dhcp server running on my laptop. I want devices to be able to connect to a wireless AP I've set up (using hostapd) to then connect to the rest of the internet via my ethernet connection from the laptop.
However, I can't get dhcp to work properly. It always fails, leaving this message in the syslog
Code: Jan 19 15:49:15 lucid-laptop dhcpd: WARNING: Host declarations are global. They are not limited to the scope you declared them in. Jan 19 15:49:15 lucid-laptop dhcpd: WARNING: Host declarations are global. They are not limited to the scope you declared them in.
My Ubuntu server is now providing routing duties to my network, but I'm having trouble opening ports to my network. I have a DynDNS account, so the IP is always current, but I can't ping even my IP directly.
My network map looks like
Internet > SpeedTouch DSL modem with DHCP > eth1 > Ubuntu > eth0 > LAN
With the modem providing a 192.168.1.xx IP to eth1, I can browse fine. The default gateway is my modem. I switched to the public IP of the modem so I could use iptables for firewall duties, but I was locked out of the internet. No gateway was set when I did that, but eth1 received the public IP of my modem.
I'm trying to build a linux(fedora 12) dhcpd server(and gateway), that have 3 network cards(eth0 have with public ip, eth1 192.168.2.1 class and eth3 with 192.168.3.1 class).
Because I have just a switch, I want to put both cables(from eth1, eth2) in the switch. Every client has 2 network card(eth0, eth1). My question is, is there any way to conf eth0 to take from server ip from 192.168.2.1 class, and eth1 from 192.168.3.1? The internet will work only on eth0.
I've noticed something strange in the behavior of how Ubuntu server obtains it's IP address versus Ubuntu desktop and other versions of linux and Windows. When Ubuntu desktop obtains an IP address from my router that address is retained from one bootup to the next, same behavior as Windows, SuSE, and pretty much any other OS. Ubuntu server on the other hand grabs a different IP address everytime it boots. At first I guessed it was a difference in /etc/dhcp3/dhclient.conf so I replaced it with the dhclient.conf from Ubuntu desktop but no dice, it still grabs a new address every time.
In /etc/network/interfaces Ubuntu server defines the loopback interface and primary network interface, just as it should but Ubuntu desktop does not define the network interface, only the loopback interface. I'm guessing something else controls does this. Desktop appears to be storing previous IP lease information in /var/lib/dhcp3/dhclient.eth0.leases but server doesn't, /var/lib/dhcp3/dhclient.leases is always empty and there's no other files in /var/lib/dhcp3/.
Apparently something isn't writing old lease info there. Without setting a static IP address, how can Ubuntu server be configured to retain the same IP address between boots like Ubuntu desktop?I'm using Ubuntu server 8.04LTS, Ubuntu desktop 9.10 & 9.04, SuSE 11.0, Linux Mint, Windows XP, pfSense 1.2.2 as router.
i already have an eth0 configured to automatically get its info from dhcp.
but i wanna configure eth1 to be able to serve dhcp and dns. i havent configured either dns or dhcp server on the server box since i have not configured the serving interface.
so far my interfaces file is:
Code: # The loopback network interface auto lo iface lo inet loopback # The primary network interface auto eth0 iface eth0 inet dhcp
Ubuntu Jaunty Server connected via eth0 to a Billion residential ADSL router. I've locked the server MAC address to a specific IP in the router and set the DHCP renewal times to the longest possible times. For a certain number of days, the server will remain connected to the router, but then for some reason (the last time it was after about a month), the server loses it's connect and dumps into syslog the following:
Code: Jun 2 17:10:15 defiant dhclient: DHCPREQUEST of 192.168.1.105 on eth0 to 192.168.1.254 port 67 Jun 2 17:11:26 defiant dhclient: last message repeated 5 times
The cable internet I'm using runs on Dynamic DHCP IP addresses. I changed it to a static IP address in my router settings, but it keeps changing. This means that I can't connect to my home server from a remote location.
Is there anyway to run my ubuntu server on a DHCP IP address without connecting through my router 192.168.1.xxx?
Fresh install of 10.04.1 server; installs seamlessly; finds network no problem.
However, establishing static connection is driving me batty. Will not take. I've reconfigured "interfaces" file several times. My fingers are numb ifdown-ing and ifup-ing and /etc/init.d/network restart-ing.
I have two files in /etc/network ... interfaces and interfaces~ (one static and the other dhcp). I can switch them in and out of play. The dhcp works and pings out like a champ. static is dead, just dead. Cannot ping router ... nothing.
