Networking :: Routing Between Two NICS On The Same Subnet?
Aug 2, 2010
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
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 have a motherboard which has 4 x 1Gbps Ethernet controllers. I would like to use it as a Gateway for my home network. I have a static IP from my ISP which I can use to configure eth0 (I haven't done it yet as the LE-565 is currently sitting behind my Netgear router until I've got DHCP working). I would like to use eth1, eth2 and eth3 for my LAN. How do I set things up so that DHCP is handing out IP addresses on the same subnet (192.168.0.0/24) on all three interfaces?
P.S. I think what I'm asking is: how do I combine all 3 interfaces to behave like a switch (ie. just like my Netgear router)?
I have a program that attaches to an interface. I can run two copies of the program on two systems (each running one instance), connect it to a switch, say 1.1.1.1 & 1.1.2.1. In this configuration two instances of the program can communicate and everything is fine.Now, to reduce cost, it want to use only one system with two nics connected to the same switch, running two instances of the above program, each instance attached to two interfaces respectively on the system. I have the following settings:
eth1 Link encap:Ethernet HWaddr XXXXXXXXXXXXXXX inet addr:1.1.1.1 Bcast:1.1.1.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
I have a pc with debian 6 (without GUI) installed on it and want to use it as server at home. It has 2 ethernet nics. Now i want to configure the routing process. Searched internet for a long time found something but couldn't get it work.
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 have a Server, which has 2 nics installed. Each of those is connected to a router, which is connected to internet. On the server, i have apache, maillserver and im-server running. On the other hand, also squid, dansguardian and clam are running. so now: via eth0 i would like to have just the traffic, which is requested from outside (the big bad internet..) to my server (apache, mail, etc). via eth1 i would like to have all OUTGOING (also to the big bad internet) from the server, which is requested by a internal client. And of course all requests to my own server
both nics shall route their traffic to their own router. For better comprehension please consult the enclosed graph. Until now, i did not find a good solution, the default route is set to the traffic from eth0, if not, no external request will find back to a client do you have a idea how to handle this the easiest way?
I want to add a fourth NIC, eth3, which will be assigned its own Public IP/Internet address (thru DHCP; my ISP provides two). The purpose it to route all net1's internet-bound traffic through eth0, and all of net2's internet traffic to eth3. This allows me to use one router/firewall machine instead of two separate ones. I anticipate that without some specific routing instructions, the default route will be eth0 for all net1 and net2 internet traffic (eth3 will be ignored).
I thought of using just one NIC (eth0) but create an alias (eth0:0), but IPtables (and possible DHCP) can't differentiate between the two (besides, nics are inexpensive). Is there a way to do this through routing commands, or even use iptables prerouting/forward functions (or is using iptables problematic)?
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 attached a diagram to show the layout, but basically I have a server that has 2 nics. I use NIC1 for the server and its services. Im using VirtualBox to run VMs and want to use NIC2 for the VMs exclusively and I want the VMs on a different network completely from the host.Ive tried setting up NIC2 on the other network but I end up with networking problems on network1. Also I cant figure out how to tell VirtualBox to bind to the host NIC2.
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.
My brother has a Ubuntu server attached to a LAN with Windows PCs. I set up an openVPN tun service on the server, let's call this VPN1, so that I can connect remotely from my Ubuntu desktop. The server has one NIC and the LAN has a router that is the gateway to the internet.
My brother would like to remotely access his windows network when roaming with his Windows laptop.
Therefore, I would like to set up a second VPN service, this time tap, that is bridged with his LAN. Let's call this VPN2.
The LAN subnet is 192.168.1.0/24. The internet gateway is 192.168.1.1
The NIC has a fixed IP set by the router of 192.168.1.150
How do I set up VPN2 so as not to trash VPN1? That is, if I bridge eth0 with tap0 how will that impact VPN1's tun0 that is using eth0? Do I need a separate NIC for the VPN2 bridge?
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 am considering moving to a software (ebox/pfSense/Zeroshell etc) based router.
It fits well to have 1 NIC connecting to your modem & the other to your switch & network. It seems to make sense it is more secure, but is it?
If I assign the 1 NIC in my router 2 IPs, a subnet for the modem and a subnet for the LAN, how is the different?
I can't think exactly what it is. I am no network guru and probably missing something down at a lower networking level, but for a home router, does 1 or 2 NICs make any difference?
My server has 2 network cards. I have SLES 10 SP2 installed on this server. I had configured Ethernet bonding on this machine using 2 NICs. Now I want to assign 2 different IP's to 2 different NICs. I am able to do this without any issue using yast. ifconfig command shows that eth0 has 192.168.1.10 and eth1 has 192.168.1.12. Rest all networking details are same (netmask, gateway, DNS)
Strange thing: When I unplug only eth0, (eth1 is plugged in correctly) I am not able to ping any IP. If I unplug only eth1, (eth0 is plugged in) I am able to ping both IP's.
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?
Ok so I'm gonna try and explain this easily. I installed 11.04 32bit on an older HP P4 machine. Boots up and goes to classic desktop.. But networking looks like a wifi devices rather than a wired connection. I installed another NIC rather than the onboard but had the same result.. I also tried yet another PCI NIC and a USB NIC with the same result. I also tried to set my connection to manual and give myself a static IP, but had no such luck.
I know my internet connection works because I'm on another machine typing this to you all.. All the NICs also work in W7 on the dualboot setup I did.
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 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.
I have two NIC's interfaces on my linux machine(eth1 and eth2). Each have different IP addresses(10.0.0.1, 10.67.7.1). These two interfaces are connected together through hub. Here is the my question?
1) If I 'ping 10.0.0.1', it should go out through network interface eth2 and through hub and enter on eth1 and response also travel through similar direction.
2) If I 'ping 10.67.7.1', it should go out through network interface eth1 and through hub and enter on eth2.
How can setup routing table for this,I have tried setting up routing and iptables, etc.. nothing helped.
If any one good router/networking guy, you should know this one.I am doing a project, I want this way to handle this.
I currently have Samba working properly using the eth0 interface on my notebook computer. More importantly, I can browse the network and see the shares set up in Samba. If I disconnect and go wireless using the wlan0 interface I can no longer browse the shares on Samba via name. I can however browse via IP address of the wlan0 interface. How can I make it so that Samba is accessible by name when I switch between interfaces?
Code:
[global] workgroup = startrek server string = NCC-1701 Enterprise bind interfaces only = yes
