Ubuntu Networking :: Change Subnet Mask "ONLY", Without Touching Any Other Setting?
Apr 5, 2010
I am using ubuntu Lucid and connected to a network with windows machines.Our network admin changed some settings in the network, and all machines need to change their subnet masks to access local machines (e.g. I am getting "unable to mount" message when I try to connect other Windows PC's on the network.)
If I open the connections panel, and "Edit" the "Auto eth0", I can get: IPv4 Settings -> Method -> Manual -> Addresses -> Add .And I am pretty sure I will put new subnet mask address into "Netmask" box, what to put others? Namely:
IP Address, Netmask, Gateway and below:
DNS Servers, Search Domains
I can get some info about my network connection by right clicking network icon on the panel, and select "Connection Information" Tried to fill manual settings with some of those info (the ones made some sense to me) but I still cannot mount windows network drives, plus my internet connection dies.So, is there any way to change Subnet Mask "ONLY", without touching any other setting.
tasks of an administrative level that we can use Shell Script to automate them. It's a kind of homework for me to figure out how to automate those tasks. Using PHP and Shell Script design and develop a Web Interface to change or set the IP Address and Subnet Mask of the UNIX / Linux System. The related services must be restarted automatically for the new IP Address and Subnet Mask to take effect. No user name and password should be asked for when using that Web Interface. How would you do it?
for providing an earlier solution from which I have modified and butchered the below script.The intended purpose of this script is to take a subnet mask for example 255.255.255.0 and turn it into the corresponding wildcard mask value in this case it would be /24I have got to the point where I have the binary value, the script is
I'm living at a friend's right now, and he's got a wireless access point in the house that I set my laptops wlan0 interface to route through the eth0 to my desktop. It's been working fine for internet sharing and internal networking ( ssh and ftp ) between the laptop and the desktop, but there's a problem with both subnets being able to communicate with each other, and I haven't been able to solve it with DNAT either.
The wireless access point is 192.168.0.1 and has its own lan on 192.168.0.0/24 of which my laptop is 192.168.0.5. I setup the little subnet I created by routing with the laptop to 192.168.1.0/24 and my desktop is 192.168.1.50. With shorewall I can configure iptables to DNAT all of my ssh traffic destined to 192.168.0.5 to 192.168.1.50, but the problem seems to occur when ssh on my desktop fails to connect rather than the DNAT failing.
Using iptraf I've seen that all of the routing does work properly, because I can see on the connection in iptraf that only the SYN packet is being sent from a 192.168.0.x address, there is no ACK packet sent back. I believe this is because in the connection dialog it always shows a 192.168.0.x ip as the source of the connection, but I don't have a route to 192.168.0.0/24 from 192.168.1.0/24 setup and I'm unsure of how to do so.
I'm pretty much in over my head because I don't know what is wrong, I thought it should work like this. Everything else from port configurations, to the configurations of the software itself seems fine so I don't think it's anything like that preventing a connection, but I can't think of what it would be aside from the lack of routing between each subnet.
Is there anyway to just add a route so that 192.168.1.0/24 and 192.168.0.0/24 can communicate with each other directly? I know there should be, I'm just not at all sure how it would be done.
I am using centOS 5.0. After I change from DHCP to static IP address, I cannot ping hosts on the same subnet. The error message says destination host unreachable. Before I made the changes I was able to ping and now even I change it back to DHCP I still cannot ping with the same destination host unreachable message. The centOS is running on VMware on a Windows host.
After pinging 192.168.0.106 (106 is on and other host can ping it), arp -a shows ? (192.168.0.106) at <incomplete> on eth0 I tried different ways by disabling the firewall and and disabling SE protection. No Luck.
I have TWO L3 + router switch (say switch1 and switch2). I created VLAN100 with VLAN ID 100 in both the switches. I created router 192.168.1.1/24 in Switch1. I created router 192.168.2.1/24 in Switch2. Switch1 is connected with 1.x/24 PCs. PCs are configured with 1.1 gateway. Switch2 is connected with 2.x/24 PCs. PCs are configured with 2.1 gateway. Both Switch1 and switch2 are connected by a trunk to carry VLAN100 data.
1)I have few PCs of 1.x connected to say Switch1 Is it possible for PC with IP 192.168.1.100(x) to ping PC with IP 192.168.2.100(y)?What are the configuration required in both switches to make them communicate ? All the device in both the subnets should ping/communicate with each other.
2)Move PC (192.168.1.100) to switch2. Move PC (192.168.2.100)to switch1.What will happen when PC(1.100) ping (2.100) and vice versa?What will happen when PC(say 1.80 in switch1) pings PC (say 1.100 in switch2) and vice versa? What will happen when PC(say 1.80 in switch1) pings PC (say 2.100 in switch1) and vice versa?
I installed Redhat Enterprise linux server5. it has two LAN card and two subnet connected to these two LAN card. i can browse network from these two network easily. But i created VLAN on one network card.Now i cant browse network from these VLAN subnet.
I have a setup samba and want to get the correct security permissions when my wife creates / copies files from her camera onto the shared/mapped drive on her new laptop (windows 7) I want the permissions set to 770 or maybe 760. See my config below.
Now I can get it to create 760 but even if I change the mask it still generates the same permissions. After every change I restart the samba service. the umask is still 0022, do not know if that makes a difference? The directory permission's are correct with this mask. Do I need to look at groups?
How can I add this to Ubuntu so that I can effectively use both networks connected to my machine. All I do in WinXP is run this from the command prompt: route -p add 10.0.0.0 mask 255.0.0.0 10.15.122.9
I have a linux desktop with two connections - fast eth0 and slow modem ppp0. Most of traffic (e-mail, DNS, NTP) can be routed simply by IP/mask. But how about http and p2p (torrents, DC++)? Routing by IP is unacceptable, because there is very huge amount of routing rules. I need route http packets (80 port) through ppp0, p2p through eth0 (10000:65535 ports). I've found that splitting traffic by port is possible with marking packets for different gateways. For begin I cleared all tables and bringed up connections.
I have a ubuntu server , can advise if I want to change the network setting ( eg. IP address , gateway address etc ) , which one is the configuration file ? for example , if I want to change eth0 setting , what file I should update ?
I have 2 x PCs and a NAS. Both PCs have 2x NICS. PC connectivity to Internet is via an ADSL router. Current config: Thus far (by choice) I've used static IPs in the 192.168.168.x range for my internal network, connecting all PCs and NAS via a jumbo frame enabled gigabit switch. This has facilitated moving data between the PCs and the NAS at high-speed. As both PCs also required Internet access from time to time, both are also connected to the ADSL router using the 2nd NIC and using subnet 192.168.1.x. I'm sure some of you are shaking your heads by now, but it works well and has been entirely hassle free.
However, I've an app running on the NAS that I'm keen to get Internet connected also. As my existing network devices are not using DHCP I figured the simplest method would be to change my ADSL router configuration such that it is in the same 192.168.168.x subnet, change its DHCP server settings to serve IPs in the same subnet (but in a restricted range I know won't cause any conflicts with the static IPs) and problem solved. On changing the ADSL router confiruration with all machines already booted up and configured as described above, everything worked. All devices could see one another, and access the Internet. On later rebooting the system this no longer works
- Internet access is fine but PCs don't see one another or the NAS. If I disconnect the ADSL Router from the PCs then all devices see one another again.
- Does having 2x NICS on a single device each assigned unique IPs in the same subnet create an issue and can it be overcome? I'd like to overcome it because making one of my PCs the gateway forces me to have it on anytime another device needs access.
- If I'm forced to use Internet connection sharing with one PC on the network connected to the router, how do I best configure this?
- One of the things I need to retain is gigabit connectivity between the PCs and PCs and the NAS (currently achieved by 192.168.168.x subnet being linked via gigabit switch).
I am trying to make Apache web server, it's work but cannot be browsed outside my subnet.I am on huge LAN network, not sure how it works, know it have TL-SL2428WEB Smart Switches and probably some kind of DHCP, every user have maximum 64KB, just plug UTP cable, and I have static address on that subnet like: "my.sub.net.ip" witch I know from Java NetworkInteface class or when I try to update IP on my www.dyndns.com Dynamic DNS account with ez-ipupdate, but my subnet is connected to Web with another IP like "my.isp.provider.ip" witch I get from whatismyipaddress.com and I check that is my Cable ISP provider web IP. It is possible that there is more subnet layers between these two IP.Problem occurs when I try to access to my web site from another computer. When I set dyndns host name to be my.sub.net.ip or use localhost everything works fine from my computer, I can access my web site, Apache work, I can use ssh. To illustrate you it work like this: Go to DNS server, find my host name, get my "my.sub.net.ip" and say "This is actually my localhost IP, no need to go on Web, lets loopback". But when I try from another computer even from my college's computer on same subnet it don't succeed. When host name is set on "my.isp.provider.ip" of course nothing works.
We, users of LAN, don't have access to our LAN nor we have admin. For example sometimes we stuck without net and we cannot even press reset button on switches or something like that, we have to wait for day to they, owner of LAN, order some professional to do that. It seems they are just user of Cable TV and IP, and they bay and install LAN without any kind of admin. Also, I use Fedora 13, with httpd, ssh and others packages that comes with Fedora 13 DVD. I know to write bash scripts, use yum, very good in C++ and Java, great programmer, but newbie in networking, , a very little Perl, html, web servers, I heard for DHCP, DNS, NAT, IP forwarding. How you see it is problem in my lack of knowledge about networking. I hope that I succeed to describe by problem with enough details. Please, try to help me. I be very graceful for any kind of help. Don't afraid to bomb my head with any kind of information hard to understand.
I've rent a server from a Germany data center,They use a single IP as their gateway that is not in range of my servers IP,Strangly server is working well and when I use 'route -n' command the gateway which is in other subnet appears properly./etc/sysconfig/network contains no gateway IP and I don't know how they set the default gateway while after reboot the gateway is the same, also the IP is static and there's now DHCP.I need to know how they did it so I can do the same on my VPSes.
I have a 6to4 tunnel running on Ethernet (subnet 2002:ad4c:16cc:1) without problem. It runs radvd and announces a default route back to the Internet like this: "default via fe80::6a7f:74ff:fe0a:fbec dev br0"
On this same Ethernet I have a Linux plugbox (fe80::225:31ff:fe01:cc) which is a gateway to a network of IPv6 enabled sensors. I've assigned this second subnet 2002:ad4c:16cc:2. How do I get the plugbox to announce "2002:ad4c:16cc:2 via fe80::225:31ff:fe01:cc" so that the hosts on the Ethernet (2002:ad4c:16cc:1) will automatically pick up the route? The route works if I add it to the boxes manually. I've tried getting radvd on the plugbox to do this but I've had no success.
I dont even know where to start looking on Google.Just in case this matters, for completeness.I've an inactive eth0 (wired ethernet link) with static IP.Other possibly relevant details:I'm using an old 802.11b card. Cant imagine this is relevant, because the internet is working fine as far as pinging anything outside the local network goes.
I have 2 NIC's in a box. One of them is external and doesn't matter for this question I don't think.
The other NIC is 192.168.100.3. It hosts an iSCSI Target and SMB Share on my LAN. It's works great.
I have another PC that has NIC at 192.168.100.101 and it hosts my DHCP (Scope: 192.168.100.5-25) server for my LAN.
I have a hardware firewall at 192.168.100.1 and it serves inet to the LAN on a different external connection.
So...
I currently have a WAP (cheap p.o.s. netgear router in WAP mode that keeps overheating). I want to eliminate the WAP device and add a WiFi NIC to the Top PC above.
So, on the first system I would have:
NIC 1: External IP and External Gateway NIC 2: Static IP 192.168.100.3 Proposed WiFi NIC 3: Static 192.168.100.4
Then I simply put the WiFi in Ad Hoc, will another WiFi in Ad Hoc (for example my laptop) be able to "see" 192.168.100.101 (DHCP) & 192.168.100.1 (Gateway) (via WiFI 192.168.100.4 through the bridge to 192.168.100.3 and on to the LAN)?
Also, can the two NIC's be bridge together even though they are the SAME subnet?
I have read NUMEROUS tutorials and explanations on the net about this, but they all seem to assume an informed understanding of IP networking. I have limited knowledge (basically I know how to set up my own home network and use the normal commands for troubleshooting.).I am doing a project at work which requires networking our new store with our original store (throughA VPN).I am just trying to understand in the most basic way how sub netting and subnet masks work. I don't believe this is necessary knowledge for setting up the network via VPN, but I would just like to understand it and I feel like I will be prepared to study further. basically:
1. How does a network mask isolate a particular host on a network? 2. How does changing the mask allow for more addresses to be used?
For example, if my address is, say, 192.168.1.36, how does 255.255.255.0 isolate my machine to receive traffic? I suppose what I am really not understanding is how it does this with more than one host on the network with the same mask.
I installed apache2 on my Ubuntu machine and I am trying to access the server from another subnet. The server is connected using ethernet and has a static ip address. I can ping from the server to any machine in the other subnet but non of the machine on that subnet can ping the server. iptables does not seem to be running
Code:
# service iptables status iptables: unrecognized service
I have some trouble setting up a printer on my network. My network is divided so that all wired connections are in one subnet, while all wireless devices are in another. My printer is Canon MP640 and is connected via wireless. When I use the network printer scanner utility from Canon, it will only scan my wired subnet, and is thus unable to see the printer. I can ping the printer, so there is no problem with subnet segregation.
On my router, I have Debian and iptables. My initial thought was that I could somehow set iptables to just forward all packets to an address to my printer. This address, of course, wouldn't exist "physically". But I have no idea whether or not this is the right approach. A suggestion I received from a colleague was to set up forwarding of broadcast packets. However, I am unsure whether this will have an impact on the wired subnet. If any of you could conjure a magical iptables rule for this or have suggestions other than plugging the printer into the wired net
I'm trying to work out how to route all traffic destined for the internet from all devices connected to eth0 to a wireless router access point via wlan0 on my Slackware box. I also have dhcpd providing ip addresses on the same subnet to any device connected to both eth0 and wlan0.
If I connect to the router/access point via wireless or directly to the Server via a crossover cable I can obtain an ip address from dhcpd, so that works. As far as I can see I just need to how to route between eth0 and wlan0 then I can provide internet access to those devices!
ifconfig:
Code:
eth0 Link encap:Ethernet HWaddr **:**:**:**:**:** inet addr:192.168.2.253 Bcast:192.168.2.255 Mask:255.255.255.0 inet6 addr: fe80::201:2eff:fe27:aea3/64 Scope:Link UP BROADCAST MULTICAST MTU:1500 Metric:1
Im trying to configure a GRE over IPSec connection between two subnets. The IPSec tunnel is opened and now I want to add a GRE tunnel over it.So, what I didn't understand is why I can't route my subnet over the tunnel, once the only route I have there says that it should route the tunnel IP over the GRE01 interface. Any hint? Thanks.
I'm trying to setup routes for a gateway that resides on a different subnet. Our ISP leased us a block of IPs and told us to route through the current gateway, which is on a different subnet than our current block of addresses. To test, I've enabled one of the new addresses on one of the existing machines, which works. That machine has an address on the same subnet as the gateway, however.
The gateway address is 24.111.1.177 One of the new addresses I'm trying to use is 96.2.192.130, netmask= 255.255.255.240, broadcast= 96.2.192.143 Obviously, I can't just specify that gateway in /etc/network/interfaces without some routing, which is where the trouble I'm having is. The machine I'm trying to set this up on is part of 2 networks - one internal, on two different NICs.
