On a remote system, when all you have is the ssh CLI -
How do you find out the ip addresses for:the Gateway
the DHCP server
the DNS server
Don't need to make any changes.
Which commands will display this info?
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.
I have installed dhcp-server on ubuntu. And server is providing ip address to clients (Window machines) but not default-gateway but I have another network in my network and same configuration and same dhcp-server provides every information.
View 5 Replies View RelatedI need to place an Ubuntu machine on a network where I have a DHCP server which does not configure the Degault Gateway parameter (we don't want ordinary users to browse the internet). Is it possible to leave the machine using DHCP and define the Default Gateway manually (as in Windows XP i.e.)? How?
View 1 Replies View RelatedWhat I need is some information to be studied and learned by me in order to be able to create with Ubuntu Server an Internet Gateway Server. From my ISP I get about 50 public routable IPs through DHCP. Into my LAN I need to forward this public routable IPs to machines but I want to be able to manage bandwidth and also to be able to enable or disable Internet access for every client machine. Maybe with subnets? Maybe with dchp really? It would be nice if it would possible through DHCP!
View 2 Replies View RelatedCurrently 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 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?
For some reason I am unable to find a DHCP Server package for Fedora 14 using yum. Does anyone know what I should be searching for or even a .rpm that can be used?
View 2 Replies View RelatedI would like to make my Fedora 13 box a DHCP server for my network. I can not find dhcpd in YUM. Is there a way to make my Fedora box a dhcp server? This was relay easy with Suse, but my Opensuse box just suffered a hard drive failure.
View 1 Replies View RelatedI'm looking for a method to assign a default gateway via dhcp randomly depending on ether the last char of the mac being odd or even, or the time the user connects. Is there a good reliable way to achieve this?
View 2 Replies View RelatedI have a simple system at home where a DSL router is used as a basic dhcp server with one port forward for ssh to a server. I need to allow my daughters, ages 14,12 and 10, to access the net and also email but I want to have complete control and logging. What I'm looking to do is set up the Ubuntu file server I already have on the network to act as a gateway and also add content management and logging as step one.
I also want to add an email server so that all the email comes into the Ubuntu server and then is allowed to be accessed by outlook on their machines after spam/content scanning for valid emails as step two. My question is what, if any, additional software do I need and what options do I have. I've played with dhcp servers at work but never got much beyond ip assignment and network booting so I'm unfamiliar with what is needed for content management and such. As to the email server I've never even played with this at all so I'm completely in the dark as to what I should be looking at to start with. I'm looking for directions, RTFM is fine but right now I'm not sure even WHAT manual/manuals I should be reading.
I am having some difficulties comprehending some networking concepts relating to multiple subnets and dhcp servers, or dhcp relay servers. I have built home networks many times before, and they have all followed a very simple formula. A single subnet, let's say 192.168.1.0 which is fairly typical for me. My network's DNS server is always also my networks DHCP server. Typically at 192.168.1.1. When a DHCP client broadcasts for an IP over the subnet, 192.168.1.1(My DNS/DHCP server) will not only tell the client what it's new IP is to be, but will also tell the client what it's Gateway server is. This is ALSO 192.168.1.1 for me typically.
In this manner, a client broadcasts for networking information and is given a usable IP, and told to use 192.168.1.1 for most other functionality. Very simple. However, I am uncertain how to expand this to other subnets. Say.. 192.168.2.0.
A: I can use a separate DHCP server for each subnet. or B: I can use a DHCP Relay agent for 192.168.2.0 to pass the DHCP requests to the primary DHCP server on the 192.168.1.0 subnet.
Option A: is fairly straight forward and have had it functioning fine, but it is really B: I want to know more about. It seems somehow much cleaner to me. I prefer to centralize as much of my network provisioning services as possible. It makes it easier to manage TYPICALLY. My question though is related to Gateways and the use of DHCP Relay Agents....
I got 2 servers, each on different locations (server 1 and server 2). I want all traffic on server1 included web browsing, applications etc., be always going through server2, like a gateway. I want the traffic to be encrypted (maybe use VPN?) So if I browse, or any logs pick up ip adresses from applications used by server1, I want it to display the IP address from server2 (Might be the wrong way to say it).
I always wants server2 to act as an firewall and logserver that logs all the traffic. I was thinking about using Snort for IPS/IDS solutions and OpenVPN for the traffic, but what can I use as a firewall? Most firewalls I find on google has its own OS/Distribution. Maybe Squid for logs? But squid does not support much protocols. Distribution on both servers are updated Debian/Ubuntu based.
I just set up a linux server which is acting as an internet gateway. For specific reasons, clients first make a vpn connection trough the internet to the linux server.
CLIENT ---->Internet----->Linux VPN Server ------> Internet
On the linux server iptables is configured for NAT. The problem is that the internet speed becomes slower than expected. I used windows and RAAS and the speed was pretty good. The server has only 1 NIC(eth0) and an alias interface is added to eth0. The alias is eth:0 with ip address 192.168.0.253
iptables config is as follows:
iptables -P INPUT ACCEPT
iptables -F INPUT
iptables -P OUTPUT ACCEPT
iptables -F OUTPUT
iptables -P FORWARD DROP
iptables -F FORWARD
iptables -t nat -F
iptables -A FORWARD -d 192.168.0.0/24 -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A FORWARD -s 192.168.0.0/24 -j ACCEPT
iptables -t nat -A POSTROUTING -s 192.168.0.0/24 -j SNAT --to MY_VALID_IP
I have been searching google for a while now and have not found exactly what I am looking for. I would like to use my fresh install of ubuntu server 11.04 as my router/gateway for my home. I am not an expert at linux by any means but I can usually figure stuff out. I believe I need iptables, bind, and a few others probally. It eventually will also be a samba server but I have done a little with samba before. I do have 2 network cards, my router at the moment is starting to die and would love to have a more powerful router. I would also like to figure out how to do port forwarding in the router, as well as be able to see the load on the network cards. Maybe there is a program to show usage by user? As well as be able to do packet pritorization.
View 4 Replies View RelatedI want to do is setup a gateway(or router, idk what Ubuntu refers to it as.). So my set up would be Modem>Server>Switch>Router. I know that I need to set up it up as a DHCP server as well. I would also like to setup it up as a firewall too. I already have two Gbit cards that are already configured. So how do I do this? I already tried one tutorial, but it was old and was for Debian. I also installed ebox, but I couldnt figure that out either.
View 2 Replies View RelatedI have setup an ubuntu gateway server by using four NIC cards.
eth0 :210.212.235.107 is connected to the internet
eth1 :192.168.1.222 is connected to the local network
eth2 :192.168.2.222 is connected to another network
Here 192.168.1.222 is the gateway for 192.168.1.0 network and 192.168.2.222 is the gateway for 192.168.2.0 network.These network configurations are working fine, but i want to block inter network communication ie from 192.168.1.0 network to 192.168.2.0 network,i want to block the communication for securing the local networks more.I know iptable rule is enough for this purpose .But i cant find the apt rule for this purpose.
This dhcp server is configured with redhat enterprise edition. I found that logs are generating in the following path /var/log my doubt is how can i setup the logs generating for a specified day.
View 1 Replies View Relatedsetup 2 gateway in my email server(opensuse).
now i wan to setup 2 internet lines for my email server, which mean that either one of the line is down, i still can receive mail from another line.
Example
Internet line 1 = ISP1
Internet line 2 = ISP2
my email server got 3 nic which...
eth0 = 192.168.1.2 (255.255.255.0) (from ISP1 GW 192.168.1.1)
eth1 = 192.168.2.2 (255.255.255.0) (from ISP2 GW 192.168..2.1)
eth2 = 168.168.1.2 (255.255.0.0) (connect to local LAN)
now existing GW set on the server is 192.168.1.1, mail receive and send through ISP1. now we wish to set somethings that once the ISP1 line is down, the server will auto switch to ISP2 gateway and continue send and receive mail without manually change of settings
I am trying to get a Linux (Slackware 13.37) working in a Windows networking environment. The IT support for this organisation does not extend to Linux support, so I'm limited in what help I can get for this.
I'm trying to get to the point where I can get to the internet to download what I need on this Linux machine.
The situation is this (*fictitious addresses used) -My Linux machine uses a fixed IP address (10.100.150.21)
My Windows machine uses a DHCP assigned IP address (10.100.150.213)Both Linux and Windows machine are configured to access the gateway server (10.100.150.1)So, I can ping the Linux machine from the Windows machine and vice-versa.I can ping the gateway machine from the Windows machine.I can browse Windows Shares on the network via SMB from the Linux machine.I CANNOT ping the gateway machine from the Linux machine with the Destination Host Unreachable message being the error message.
For actual internet access I need to access a proxy server but since the Linux machine can't even ping the gateway server, it fails to ping the proxy.Now, I have been told the gateway is a HW based router and for Windows machine they use some software for authentication to connect to the network. This software isn't available for Linux, so that's why I've been told to use a fixed IP address.My experience of networking is pretty basic and most of the Linux setup is done via running Slackware's setup program.
I posted it on another forum, but could not get response,So I have this cenOS, Ubuntu and windows operating system running on virtual machines.Now I gave them manual ip address, both ubuntu and windows machines can ping the default gateway, but not the CentOS.It should forward 0.0.0.0. to my cisco router address(192.168.5.254),
View 4 Replies View RelatedSince I have a new internetaccount, 2 days ago, I have a problem on my server [Fedora Core 8]. I use it as a router.
eth0 is for the internet.
eth1 is for my LAN.
But since my new internetaccount my server uses eth1 for the internet. This is a line from my syslog:
Code:
NetworkManager: <info> Policy set 'System eth1' (eth1) as default for routing and DNS. I killed the NetworkManager daemon and now it works but this must not be the way to do it? Where do I tell my server that I use eth0 for routing and DNS?
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")
View 7 Replies View RelatedI 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.
View 5 Replies View Relatedi 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.
View 9 Replies View RelatedI have been beating my head for the last few weeks on this problem, (although I have been taking the wrong approach, it seems).
I need a gateway to direct web traffic to three separate servers/domains. I have been trying to do this with both a dns server and , (seperatly), apache server to forward requests. The dns server was a no go, and <i can only get apache to redirect http and ftp.
After Googling this ALOT, I believe that what I need is a gateway server to redirect my traffic to the 3 different servers. I have been reading about using using nat and iptables for this and was wondering if anyone had any advice/suggestions on this. The other thought I had was to use something like pfSense to create the gateway, but I am still reading the documentation, and I am unsure if this approach will work.
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.
View 4 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'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.
[Code].....