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.
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I 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 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 RelatedBack 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.
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?
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 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 RelatedI 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 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.
This is slackware 12. I'm trying to share my internet connection (on eth0) with a computer connected to eth1.
eth0 is 192.168.0.101, eth1 is 192.168.1.100 (different subnets).
But when I try to make eth1's default gateway the same as eth0's, see the error I get code...
I am in a big confusion and searching an answer to calm down my mind.I have my eth0 has following configuration
` ` `
IP 192.168.1.100
mask 255.255.255.0
[code]....
I have installed ubuntu 9.04 Jaunty server from disk. I am connect to my corporate internet. I have put in my http_proxy everywhere I can find to put it. I am getting an ipaddress, gateway, broadcast,etc. My wired is connected. When I try to ping my default gateway it times out. %100 packet loss. I get the ipaddress of the gateway from the (route command).
My configurations on /etc/network/interfaces is correct(I am on another computer so I can't copy and paste) and I even tried updating the drivers for NIC card. I am using a Intel 82567LM-3. I have been working on this longer than I care to admit.
Im trying to achieve the multiple uplinks/provider found on LARTC.org. I have to get the IP addresses from my interfaces (EF1 and EF2) by using a script, but i dont know where to look at for the default gateway from each interface which got their ip address from my ISP.
View 1 Replies View RelatedI have a computer with two interfaces: a fixed connection (eth1) and a modem (ppp0). My goal is to receive UDP packets from both connections concurrently (using the recv() function). The problem is, that the received packets reach the application only when the default gateway is set to that interface's address. For example, if I set the default gw to be in the eth1 subnet, only packets from eth1 reach the application. Other packets are received in the interface (checked using tcpdump), but they seem to be blocked somewhere. The policy defined in iptables is "ACCEPT" for all incoming packets, with no rules at all. I would like to know how to overcome this problem, and anyway how is the default gateway related to incoming UDP?
View 3 Replies View RelatedI have a dual-homed Debian server running squid, but not acting as a router. Simplied network diagram is below - there are other local hops between the gateways and the Internet.
Code:
(eth0 @ 192.168.44.2) <--> (Gateway1 @ 192.168.44.1) <--> Internet
(eth1 @ 192.168.55.2) <--> (Gateway2 @ 192.168.55.1) <--> Internet
Using Gateway1 gives a very fast, but not always reliable route to the Internet. Using Gateway2 gives a slower, but more reliable route to the Internet. The server uses Gateway1 as the default gateway.
I have written a script that pings three hosts on the Internet, and if all three are down, switches the default gateway to Gateway2. This part seems to be easy, but I'd like know if there is a way of routing a ICMP/ping out eth0 to a host, with all other traffic to the host going out eth1, so I can determine if the Internet is reachable via Gateway1 again.
I am realtively new to BGP. I use BGP in my network to advertise my /20 subnet. What i would like to know is what is the point of accepting routes from your neighbouring AS(ISP)?My ISP has given me a default gateway, and no matter what I want to reach on the internet I have to go through that default gateway, so why populate the routing table with soo many routes?also, as i understand it, there are 3 kinds of routes that you can accept, those are full routes, directly connected routes and default routes. What is the diffrence between them and again how do they affect routing since my network only has the one default gateway?
View 2 Replies View RelatedI had a router crap out yesterday. I'd been testing out a new one for the last few days and just reconfigured it to be the main. Took the old one down and everything in my house (Windows 7 PC, XP Files server, Ubuntu PC , windows 7 laptop, android tablet, ps3, etc) seems to be working fine whether it be hard wired or wifi. All except my ubuntu 10.04 laptop. It worked fine before the swap so I can't figure out what's going on.
I'm able to connect to the new SSID without issue but I can't resolve any external names and when I try to ping the default gate way every other packet has (DUP!) behind it. If I'm hardwired I don't get the dup! when pinging the default gateway but I still can't resolve any external names. I have provided the results of an ifconfig and the results of a ping to the default gateway below.
cooley@Quigon:~$ ping 192.168.1.1
PING 192.168.1.1 (192.168.1.1) 56(84) bytes of data.
64 bytes from 192.168.1.1: icmp_seq=1 ttl=64 time=2.98 ms
64 bytes from 192.168.1.1: icmp_seq=1 ttl=64 time=3.04 ms (DUP!)
64 bytes from 192.168.1.1: icmp_seq=2 ttl=64 time=3.50 ms
64 bytes from 192.168.1.1: icmp_seq=2 ttl=64 time=5.72 ms (DUP!)
64 bytes from 192.168.1.1: icmp_seq=3 ttl=64 time=8.09 ms
[Code]...
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 RelatedStruggling to get my Linux server accept ICMP redirects not originating from default gateway. No problem to get it working if the redirects is originating from def gw.I know it's not a good solution security wise, but my network is so cluttered I'm forced to do so.
View 1 Replies View RelatedClient which uses an ISP with a Linux machine (Server 1) with two network cards. Eth0 with ip 1.1.1.2 and gateway 1.1.1.1 these ip's is not public ip's and falls unders the isp's internal range, eth1 with the internal ip range. OpenVPN listen on eth0 for incoming connections. We want to connect to Server1 from external networks. Due to different reasons the isp could not get the routing sorted and give us an public ip on his network. We had to setup another bos (Server2) with eth0 2.2.2.5 and gateway 2.2.2.1 which is public ip's and eth1 with ip 3.3.3.5. Server 2 can communicate via the ISP internal network with server 1. I use DNAT to forward all incoming connections on server 2 to server 1 but the problem I have is that server uses its default gateway for the return packages and does not sent the reply back to server 2. My iptables rules looks as follows on server 2.
/usr/sbin/iptables -t nat -A PREROUTING -p udp -i eth0 -d 196.25.157.135 --dport 1194 -j DNAT --to 192.168.100.170:1194
/usr/sbin/iptables -A FORWARD -p udp -i eth0 -d 192.168.100.170 --dport 1194 -j ACCEPT
I'm using OpenWRT on a WRT54GS. I'm using wifidog in combination with openvpn. For those of you familiar with wifidog, my auth server is located at the other end of an openvpn tunnel and the "wifi dog gateway" is running on the WRT itself. I'm don't really think that wifi dog is the issue. Basically, I'm using openvpn with the "redirect-gateway" option which works well. In this mode, openvpn removes my current default gateway setting and adds the remote openvpn server as the default gateway (as it should). However, overnight, my default gateway on the local network keeps reapperaing (along with the openvpn one as well).
This causes confusion and I don't want any packets (But ovbiously the connection to the actual openvpn server) to go down this local gateway. Why do you think it reappears? Do you reckon openvpn is dropping connection and somehow the normal gateway is being added back? I *could* run a cron script which runs every minute or so with something like "route del default gw xx.xx.xx.xx" (where xx.xx.xx.xx is the default gateway which I don't want to be there) but that is quite messy and means that if I were to ever move the router I would need to reconfigure this and considering that I would like in the future to have many of these wifi dog gateways, this really isn't an ideal option (as every network will have a different default gateway).
I could not able to configure the default gateway ip address onto the system. i use the route command (" route add default gw 192.xxx.xxx.xxx eth0 ") to add a default gateway onto the routing table but it is "disappear" in the routing table when i had restart the service network.
View 3 Replies View Related5.10 Breezy configured as machine controller. Works great eth0 is a fixed IP to communicate with controller comms board. Not easy at all to alter - the comms board is hard coded to listen on eth0 for commands.
I can use eth1 as the default gateway and ping google.com, etc. But when I now attempt to communicate with the controller with netcat, e.g.
Code: echo !HH | nc 192.168.1.6 80
I obviously never get an answer since the request is passed via eth1. Using the -g option with netcat doesn't work either. I had a look at iptables but it doesn't seem to be able to do what I want. How I can still use eth0 as my communication port to the controller whilst eth1 is the default gateway?
I've been struggeling with this for a few hours now, googleing and so on trying to find an easy way to just switch which device I want as primary for internet connections. After long battles I'm at a loss, this is the current automatic routing
Code:
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
85.225.76.0 0.0.0.0 255.255.252.0 U 1 0 0 eth0
85.225.76.0 0.0.0.0 255.255.252.0 U 2 0 0 wlan0
[Code]...
I want to use dhcpcd instead of dhclient on Ubuntu. The 'interfaces' man page say: "The dhcp Method This method may be used to obtain an address via DHCP with any of the tools: dhclient, pump, udhcpc, dhcpcd. (They have been listed in their order of precedence.)"
I can't find where to change this default order. I can uninstall dhcp3-client, but this will also remove ubuntu-minimal, which is not a good solution.
I would like to use dhcpcd instead of dhclient in my Debian installation, because I had some trouble with dhclient in the past and I assume the problem is still exists now with some equipments.
So I would like to use dhcpcd, but I couldn't find a way to tell the system to give higher priority to dhcpcd than dhclient.
Also, I've tried to remove the package 'isc-dhcp-client', but it also would like to remove the following packages: isc-dhcp-client knm-runtime network-manager network-manager-kde
Moreover, it says no need the following packages anymore: usb-modeswitch dnsmasq-base libnm-util1 usb-modeswitch-data network-manager-ppp pptp-linux network-manager-openvpn libnm-glib-vpn1 libnm-glib2 modemmanager vpnc network-manager-vpnc
I would like to still be able to use kde-network-manager, because it is much easier to manage wifi connections using this interface.
Does anyone know if you switch networks Where you have your servers hosted on a Non-DHCP Network, and you switch your IP addresses, then do you have to switch change/assign your new gateway address? I'm not sure if its manually assigned? How do you do it? Also what about nameserver resolving?
View 2 Replies View RelatedI trying to set up a cluster of 4 nodes each with CentOS 5.3,
i want to rsh from one node to other without providing the password.
so far i did the following:
1)configured /etc/hosts file on the nodes so that each node can be pinged from other.
$cat /etc/hosts
10.0.2.100 node1
10.0.2.101 node2
10.0.2.102 node3
[Code]....
but it still is Asking for the password!
I am not able to figure out what to do next ? Do i need to be at /home/mygrid location on node1 in order to rsh into node2 ?
