Do I undersatnd correct? If you build LAN with several Linux PCs and no DHCP server, you will need to configure every computer yourself. But if you add one more PC to this LAN which is DHCP server, all you need is to configure this DHCP server and write in config files of other computers to use DHCP, network will work without configuring other computers?
View 6 RepliesBack 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.
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?
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
View 2 Replies View RelatedI am wanting to build myself a Linux based firewall and network switch but I am not entirely sure where to start. I would like to point out that I am aware that it would be easier and quicker to just buy a switch and use that, but this is an intellectual exercise.
What I want to do is have a NIC which has the internet coming in. The traffic is then passed through the firewall program (I think IP tables is what I should be using?).
Now my main issue is that I will have quite a few Network Interfaces to manage. The machine could easily assign IPs by DHCP and act as the DNS server but what would I need to use to share the internet connection to all the NICs? There will be at least 4 interfaces, but possibly up to 12.
I am trying to do my graduation project, it's labeled under "linux secure router", and I should build a linux based router equipped with firewall and ACL management...Some people advice me to use linux ubuntu distribution todo this I try to do that but I don't know where to start form
View 3 Replies View Relatedfirst: PXE flawless bind to dhcp address but put next binding state to free second: when installer calls init script to reinit ethernet driver (e1000 (vmware)) binding fails 11.2 opensuse fail to reinit dhcp with log entry "no free leases" third: when manual set network install works how to preserve dhcp lease on reinit of driver?
View 1 Replies View RelatedI want to run networking on my laptops in different environment (home, office, airport etc). I found that Netowrk Manager assigns information from DHCP although I requested fixed IP and configured the gateway and DNS. If I reconfigure the DHCP server so that there is no free IP address, the laptop refuses to connect. When I remove the interfaces from the network manager, I get the fixed IP address, /etc/resolv.conf is not overwritten from DHCP but WiFi connection cannot be established, there is no dialog for setting WPA-PSK. The static IP address seems to be taken into account only if the DHCP server is not found. I need the static address at home and in my office because I need the possibility to ssh to my laptop from another computer but I need IP from DHCP possibly authenticating against RADIUS (Eduroam) when travelling somewhere else. Is there an easy way how to achieve it and how to switch profiles easily? And I cannot switch DHCP off because some devices in my LAN cannot work without it.
View 6 Replies View RelatedI 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.
View 4 Replies View RelatedI have an old tower that I've installed Ubuntu onto. It connects fine online with a mobile broadband stick. I also have an old wireless router knocking about, and I've been trying to network up my house wirelessly using the tower as a router, if that makes any sense. Long story short, this is my setup
Internet ==> Mobile Broadband ==> Tower ==> Wireless Router ==> Wireless Devices.
I know that it's complicated, but I'm sure that it can be done. I've tried playing around with bind9, and playing with dhcp and the like. I feel that I am close.... but no cigar. how to route all traffic from the router
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. However I have no idea how this could be setup.
View 2 Replies View RelatedI have built a linux router with a pc having two network cards. I am running ubuntu 8.10.
I have enabled forwarding on the router. One network (192.168.1.0/24)is connected to eth0 and another (192.168.2.0/24) is connected to eth1.
The interfaces have addresses 192.168.1.1 and 192.168.2.1.
On any side side of the network, I can ping both interfaces on the router.
However when I ping a machine on the other side of the network, I get 100% packet loss.
I have not touched iptables on the router or any machines.
What I am doing wrong?
apparently someone on my LAN is running his own DHCP server (by mistake i assume) and broadcasting an address (it is 192.168.1.155) prevents me to connect to the 'real' DHCP server (195.249.186.1) thus the internet. how can i connect to my usual DHCP server? what commands should i use?
View 5 Replies View RelatedI have made a CentOS AMI Image for Amazon EC2 Now the network is starting but it doesnt even try to determine the IP :
Bringing up interface eth0: [ OK ]
BUT if I hit the ifconfig :
eth0 Link encap:Ethernet HWaddr 12:31:39:0A:99:F8
inet6 addr: fe80::1031:39ff:fe0a:99f8/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
[Code]......
I have DHCP server running on CentOS-5.4.The dhcp version is 3.0.5 In the dhcpd.conf file I want to use "update-conflict-detection". But, when I add the line as
Code:
update-conflict-detection false;
and after saving the file when I restart dhcpd, it fails. I read somewhere that dhcp version 3.1.x supports my requirement. Is it required to update dhcp? If yes, how can I update?
i've set up an openvpn server (with dhcp running on it) and i have to create compatible clients.the problem is how to get an ip by dhcp.with ubuntu i made a script like this
/sbin/ifconfig tap0 up
/sbin/dhclient -e tap0
and everything works fine:tap0 goes up and then start a dhcp request to the server on tap0with fedora there is a nice problem i've noticed that is impossible to run dhclient later on a new interface because i receive this error "dhclient is already running".the tap0 goes up normally but i receive this error when i attempt to get an ip.is there a simple way to get an ip?if i try to kill or restart dhclient when the vpn tunnel is up,all'interfaces lost theirs ip and network goes down crashing my vpn...
how to let iptables to allow dns & dhcp distributions from the server to the clients only w/out exposing the port dhcp port udp 67,68 and tcp port 67,68 as well from the outside world.DHCP only uses udp, but still I also allowed tcp ports as well just to be sure & also I already allow DNS ports in the firewall w/c is not inluded below. linux newbie here,
when i issued the command below to allow those ports only to the internal network the firewall still blocking it. what seems to be the problem?? #iptables -A INPUT -m iprange --src-range 192.168.0.1-192.168.0.254 -p udp --dport 67 -j ACCEPT
[Code]...
I have a small server that will collect industry machine info and report it to our main server here. Now, we plan to make a few of these units but we will need to be able to remote into them (ssh) to kick off the operations when they are delivered. Problem is, how can i ssh into a machine that has an ip given by dhcp? I could have the server send me it's internal and external ip, but that still does not open port 22 (or whatever i need) on the router so i can get to it from an outside line.
View 3 Replies View RelatedI had my laptop at work for a few days and when I brought it home I couldn't open up web pages any more. I have a DHCP connection (shaw cable).When I plug the chord from the modem into my windows machine I can open up web pages. When I plug it into my ubuntu laptop I can't open up web pages.
I have tried unplugging the modem and restaring my computer.I think that there is some sort of connection because when I open up Network tools it shows that I am continually receiving packets. As soon as I unplug the ethernet wire I stop receiving packets. For some reason I just can't open web pages.I also tryed typing 'sudo ifconfig' and 'sudo dhclient' in a terminal. I don't fully understand what this means but I saw it in another forum.
I just installed ubuntu for the first time, and I am not very familiar with everything yet but i am trying to connect to my university's wireless network and can't seem to figure it out. These are the directions they provide for linux users:
Use linuxconf Start linuxconf, go to Basic Host Information under Networking and Client Tasks.
Click Adapter 1, and select DHCP.
Click OK and Apply Changes.
Finally, reboot
I tried running linuxconf from the terminal but no such command exists, is there a similar one for ubuntu?
Recently, I have encountered a problem when setting my network configuration.I want to automatically get an IP address through DHCP at system startup, and this can be done by editing /etc/network/interfaces file, adding
auto eth0
iface eth0 inet dhcp
The problem is that I want to set a static DNS, but DHCP will automatically overwritten /etc/resolv.conf file.
What should I do?
Is there a way to configure DHCP IP Reservation thru MAC ? eg. {MAC ADDRESS} 192.168.1.23 So, when somebody owns this MAC address leases IP, it will give the one in reservation. Also, for security in mind, DHCP will ONLY lease IP if its MAC address is listed, otherwise, DHCP will NOT give IP.
View 1 Replies View RelatedI have a MB with 2 NICs and on 1 I would like to have a static IP, on the other a DHCP for a local network.The problem is the DHCP provided gateway is made default vs the one for the static IP and resolv.conf is overwritten.Any suggestions how could this be resolved? I can tweak both the DHCP server settings and the box settings.
View 14 Replies View RelatedI'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.
my dhcpd.conf for now looks like this:
subnet 192.168.2.0 netmask 255.255.255.0 {
option subnet-mask 255.255.255.0;
option routers 192.168.2.1;
[Code]....
I want to provide dhcp in different NIC which are eth3 and eth2. eth2 has the IP address of 192.168.3.1 and eth3 has the IP address of 192.168.4.1. I want to provide dhcp to 192.168.3.0network and also for 192.168.4.0 network.All these are done in ubuntu server.
View 1 Replies View RelatedI want to bond two NIC to the same IP, I was able to do this for Static IP but not DHCP.
Does anyone have any idea about the possibility of this?
The process at which i reached to this question is explained here:
http://ubuntuforums.org/showthread.php?t=1645440
I am doing a project on which i need to switch between dhcp and manual network configuration. I want to know how can i set dhcp programatically. I will not be able to edit any config files as my file system is read only. i am looking for some APIs which could do the task.
View 2 Replies View RelatedI've searched on issues of multiple DHCP servers in one LAN. Just about everything is Windows or Novell based stuff. Also, the typically asked scenario is 2 or more DHCP servers for failover purpose (one goes down, the other takes over).
What I want to do with DHCP is different. My purpose would best be described as "administrative separation". Basically, if a given MAC address is configured on a specific DHCP server, that server should be the one to answer and not the other. The problem with that is that we also need a default to handle unknown MACs. So the DHCP server without the MAC configured would be answering, anyway, even if it is the only one configured to do global leasing. Timing would then be the determining factor.
The purpose is to set up a bunch of PXE network booting using program generated DHCP configuration. This server won't always be up, so it can't be used for general purpose. The DHCP server for general purpose is part of a wireless system, and it is configured by GUI and is impractical for the programmed PXE booting.
how to make these work together with everything being on the same LAN segment?
I have linux running from a cd rom when I need to start linux. I have the dhcp program on my computer and I need to save it to the cd rom with the linux system on it. The dhcp program is in my /users/bennett/downloads/dualserverinstallationv6.83 folder. So how do I get ths save to my linux system on the cd rom so I can use it in Voiphopper.
View 1 Replies View Related