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12
votes
4answers
3k views

How to identify NICs that are connected to the same switch from a Linux box?

Initial Setup As a Linux administrator you have installed a fresh Linux box with 6 NICs eth0 to eth5. The eth0 interface is correctly configured and all other interfaces are currently up but without ...
8
votes
2answers
3k views

How do I update my /etc/network/interfaces file so the box comes up with ONLY IPv6 self-assigned address?

I apologize for this blatantly newbie-ish question, but I'd like to do this "the right way" and not just muck about until it seems to work, and the documentation I have doesn't seem to address this ...
8
votes
2answers
202 views

Packet captures: filtering on RX vs TX

I have a network problem where frames with a source MAC which matches with one of my host's source MACs are arriving at the host - an apparent duplicate MAC, or loop, or other L2 problem. I believe ...
7
votes
1answer
15k views

Two network adapters on Ubuntu Server 9.10 - Can't have both working at once?

I'm trying to set up two network adapters in Ubuntu (server edition) 9.10. One for the public internet, the other a private LAN. During the install, I was asked to pick a primary network adapter ...
6
votes
5answers
2k views

Is there any way to force my Linux box to always boot up with a self-assigned IP address?

This is perhaps an unusual request: I'm trying to get a Debian Linux box to always give itself a self-assigned IP address (i.e. 169.254.x.y) on boot. In particular, I want it to do that even when ...
6
votes
3answers
622 views

Why is there less latency on loopback than on a carp interface?

Stack Overflow Careers is served up something like so: user -> internet -> our fw -> nginx -> haproxy -> web farm FreeBSD is the operating system in use no firewalling or QoS is in ...
5
votes
1answer
2k views

Syntax for include files in /etc/network/interfaces

I want to organize interface aliases (for example eth0:1) in separate files (/etc/network/conf.d/eth0_1.cnf). Anyone know the syntax to load this external file from /etc/network/interfaces, or where ...
5
votes
2answers
3k views

/etc/interfaces file for multiple gateways, same network? (linux)

I've got my ip routing table setup as I'd like it: # ip r s 10.1.248.0/24 dev eth0 proto kernel scope link src 10.1.248.11 default via 10.1.248.1 dev eth0 metric 100 default via 10.1.248.3 dev ...
5
votes
3answers
1k views

Xen alternative for VMware Infrastructure

Is there any Xen alternative for VMware Infrastructure? Any aggregation and control interfaces?
5
votes
2answers
2k views

Linux email server for sending email from multiple IP addresses

I'm trying to setup an email server so it has the capability to send email from multiple IP addresses, so our marketing system can send email from multiple domains, while keeping the reverse DNS ...
4
votes
3answers
32k views

What is a Cisco BVI interface? What is it used for?

I have been Google'd and searched for the answer to these questions, but I cannot find a simple answer. So my questions are about BVI interfaces. What are they? Why do you use them? In what scenario ...
4
votes
1answer
419 views

Strange ifup/ifdown behaviour on Debian Lenny

First of all, here is my /etc/network/interfaces auto lo iface lo inet loopback auto eth0 iface eth0 inet static address 10.10.4.142 netmask 255.255.255.0 gateway 10.10.4.1 auto eth1 iface ...
3
votes
2answers
492 views

Does the network need to be restarted after editing /etc/network/interfaces?

On Debian - Say I have a network card eth0 on my /etc/network/interfaces file, and I want to add a new interface to it (that uses dhcp). Is it necessary to restart the networking service ...
3
votes
3answers
2k views

linux vlan routing

I've got this network topology: network 192.168.100.0/24 vlan 100 network 192.168.200.0/24 vlan 200 one ubuntu server(2 vlans on 1 ether) eth0.100 (ip:192.168.100.10/24) eth0.200 (ip: ...
3
votes
2answers
2k views

Samba domain trust errors on a specific interface

We have a windows domain that also has a RHEL member server in it. All the servers have a primary network connection to the LAN, but some servers also have private dedicated links to the RHEL server, ...
3
votes
2answers
2k views

Hostname resolution in a machine with multiple running eth ports

Consider a machine having 4 eth ports running on it. Then to which eth port's ipaddress will the hostname resolve to? Kindly guide me to some documentation to support your answers so that I could use ...
3
votes
3answers
742 views

Round robin through multiple interfaces

I'd like to alternative between networking interfaces to a particular ip. For example: Request to 192.168.1.5 // uses interface 1 Request to 192.168.1.5 // uses interface 2 Request to 192.168.1.5 ...
2
votes
2answers
200 views

Consistent Naming of 10gbps Interfaces on Dell Host

I have some Dell hosts in our environment. I would like to be able to provide consistent network interface naming across platforms. I know that biosdevname attempts to make the interfaces consistent ...
2
votes
2answers
278 views

Do newer physical interfaces make a better linux firewall?

At work we use an old (10 year old) linux box with 4 interfaces to act as router/firewall for the network. There's never really been a need to change it since it's stable and handles all our needs. ...
2
votes
2answers
349 views

Networkconfig on Debian-based Linuxes

Question: I've some Debian or Ubuntu based servers here with allow-hotplug eth0 and some with auto eth0 in /etc/network/interfaces. What is the difference between them? If I'm correct, both ...
2
votes
1answer
5k views

Bringing up network interface without IP configured in Debian, for XEN dom0

I have 3 NICs that I want to be seen by my domU, even though they're not configured in dom0. Here's my sample lines from interfaces file auto lo iface lo inet loopback # Local network, cable ...
2
votes
3answers
417 views

Linux router with 4 NICs not working

I'm setting up a Linux based router, with 4 NICs, and I can't seem to convince it to work, despite following steps suggested on various web sites. Each interface is on a separate subnet as follows: ...
2
votes
2answers
1k views

How do I configure an interface to have *both* a DHCP address and a static address in Ubuntu?

In a lab setup, I want eth0 on a Ubuntu server box to get a DHCP address for talking to the outside world, and I also want to assign it a static 10.x.y.z address for talking to other boxes on the ...
2
votes
2answers
949 views

ip over specific network interface

I have two network interfaces with respective ips eth0 : 192.168.70.153 eth2 : 192.168.70.155 when I make route -C Kernel IP routing cache Source Destination Gateway ...
2
votes
1answer
258 views

bridging real and virtual wireless network interfaces

I have 2 wireless interfaces, one real (eth1) and one virtual (vt0), running on top of the same physical wireless adapter. Both have separate IP address spaces. eth1 is connected to a laptop, and vt0 ...
2
votes
1answer
3k views

Routing OpenVPN tunnel in via public interface and out via NAT'd interface (to internet)

I hope someone can help... I want to Configure OpenVPN-AS (i.e. OpenVPN Access Server, NOT OpenVPN) to work on my VPS. The VPS is a KVM running Ubunto 10.04 LTS, with a very vanilla configuration. ...
2
votes
2answers
198 views

“Symbolic link” for NICs under Linux?

Currently on my Linux server I've enabled bridging so that I can use OpenVPN in bridged mode. Works great. eth0 is connected to the LAN; tun0 is the OpenVPN gateway; these are bridged to a new ...
1
vote
1answer
226 views

Is it possible plugging in a crossover cable to a 1Gb network adapter fried my adapter?

The host I am working with has two network adapters and is running Ubuntu Server 12.10. In an attempt to network two computers I used a cross-over cable as in the old 100Mbps days. After doing this I ...
1
vote
2answers
185 views

How to set ip address permanently

This might sound a little strange, but I try to achieve to set up an ip address permanently in Ubuntu using the command line, but not an editor. My idea is to provision servers and just type in the ...
1
vote
1answer
263 views

Static network interface settings in Ubuntu [closed]

I am following the guide here to configure a fresh Ubuntu 12.04 server installation (running in VirtualBox) with a static IP address. The recommended configuration in /etc/network/interfaces is: auto ...
1
vote
1answer
397 views

How do bridges really work?

I'm in a major confusion here, regarding bridges. I thought that they were devices that allowed going from one network to a different one without routing (doing the work at layer 2 instead), but if ...
1
vote
2answers
1k views

interfaces/static IP problem - Debian

I'm trying to configure my Debian machine (Lenny) to use a static ip address. Here's what my interfaces file currently looks like: # This file describes the network interfaces available on your ...
1
vote
1answer
555 views

Ubuntu: Multiple NICs, one used only for Wake-On-LAN

This is similar to some other questions, but I have a specific need which is not covered in the other questions. I have an Ubuntu server (11.10) with two NICs. One is built into the motherboard and ...
1
vote
1answer
4k views

Setting a static DNS nameserver (Debian Squeeze)

I have a gateway running on Debian Squeeze with 2 network interfaces, one static (internal, eth0) and one DHCP (external, eth1). I have an internal DNS server that I want the gateway to use. In my ...
1
vote
1answer
5k views

How do I configure multiple IPs on an Ubuntu server with two Ethernet ports?

I am trying to set up four IPs on two Ethernet ports. I figured I will assign one to each and then create aliases for the remaining two. This is what I did with my limited networking knowledge: # ...
1
vote
4answers
2k views

Cisco Switch: trigger mac-address table update

If I run show mac-address-table dynamic I get a bunch of mac addresses on that table. But due to the aging parameter, I don't see the mac addresses of all possible devices on the network that come ...
1
vote
2answers
2k views

Problems bringing up a second virtual network interface

I'm having issues adding a second IP address to one interface. Below is my /etc/networking/interfaces # The loopback network interface auto lo iface lo inet loopback #eth0 is our main IP address ...
1
vote
3answers
583 views

Bring up a virtual interface without checking if it's up elsewhere

Is there a way to bring up a virtual interface without it first sending an arping to check if that IP address is already in use elsewhere? I'm working with a proprietary product that recommends ...
1
vote
2answers
7k views

how to configure modprobe to recognize newly installed driver for eth1 on bootup?

I have a server running Debian 6. My motherboard has two interfaces, eth0 and eth1. Debian does not have a driver for eth1 (e1000e), so I installed the driver provided by Intel (e1000e-1.4.4). ...
1
vote
1answer
364 views

Solaris 8: Assign equal priorities to multiple primary interfaces connected to the same network

I have a machine with Solaris 8, and it has multiple interfaces that are connected to the same network which means they all have metric 0 (1 hop) to the default gateway. assume: e1000g0: ...
1
vote
1answer
650 views

eth0 doesn't start after interfaces modification

Just installed Ubuntu Server 10.04 on VMWare ESXi 4.0.0 (201167) and changed the interfaces file. My (modified) interfaces file looks like this: auto lo iface lo inet loopback iface eth0 inet ...
1
vote
1answer
257 views

How to prevent response to who-has requests on virtual eth interface?

we use small embedded X86 linux servers equipped with a single physical ethernet port as a gateway for an IP video surveillance application. Each downstream IP cam is mapped to a separate virtual IP ...
1
vote
1answer
165 views

How to fill in the network line in the ubuntu interfaces config file?

I have to configure an ubuntu hardy server network interface. The service hoster told me that this is the network data for the machine: IP Range: 111.111.200.74 to 111.111.200.78 Netmask: ...
1
vote
3answers
191 views

Make interface attachment permanent in Xen 3.2.1 Debian Lenny Dom0

I'm trying to add interfaces to a DomU (either on the fly or after reboot) and the attach-interface script works just fine. The problem is that when I reboot the DomU the interfaces added are ...
1
vote
2answers
1k views

XenServer 6.2 changing mtu

So I've looked around for a way to change the MTU of interfaces on XenServer 6.2, but can't find anything that works for me ... One method spoke about changing the ifcnfg-intX files in the ...
1
vote
1answer
273 views

Cisco Nexus: list all interfaces with their ips

This is the same as this question, but for Nexus: Junos: find out each interface's ip I need to show all interfaces with their respective IPs. I know that on IOS I can get that with show ip ...
1
vote
1answer
964 views

Junos: find out each interface's ip

Sorry if my explanation is confusing. I need to get all the ip addresses of a Juniper Switch and Router (different models). On Cisco IOS I can get that with show ip interface brief | exclude ...
1
vote
1answer
153 views

Extract ip, mask and gateway of a network interface separately

I know that the command ifconfig will give you ip, mask and gateway of a given network interface. I want to "programmatically" extract each of those paramaters separately. At the moment the best ...
1
vote
1answer
189 views

Route Traffic Through Linux Server With Two Devices

Here is my current setup (all servers are Ubuntu Server Edition 12.04): Server 0 has two devices, eth0 and eth1. eth0 is connected to the wall (the internet), and eth1 is connected to a switch. ...
1
vote
1answer
2k views

Debian KVM host and guests interfaces configuration

I've got dedicated Debian server with Proxmox as KVM manager and such IP example network: IP address 175.19.59.209 Netmask 255.255.255.224 Gateway 175.19.59.193 Now I'm trying to configure ...