two network cards

[jdk85]

hi

i am a newbie with vicidial servers. first, i want to understand the use of two network cards. second, how do i setup it correctly? currently, the eth0 (onboard) is connected to a router. eth1 (network card) is connected to a switch. eth1 is not up (disabled).

[boybawang]

you need to configure both interfaces in static mode, refer to google for more information

[jdk85]

yes i have configured each interfaces with static IPs. eth0 on local and eth1 for public. i want to understand what is the use of using two network cards.

[Rudolfmdlt]

Hi JDK.

Do you have any Linux experience?

There is no set use for the nic's, you use as many as you require for each install. You can get away with just one Nic.

Which manual are you reading?

Rudolf

[deficit]

yes i have configured each interfaces with static IPs. eth0 on local and eth1 for public. i want to understand what is the use of using two network cards.

Well one network card could be your public internet connection with a static IP and the other could be your internal lan ie 10.10.10.1.. But I think you are asking the question why do I need 2? short answer you dont..

[jdk85]

Yes. There is no problem running with one network card. Here is the situation:

I took over operating the server. I was instructed to have it reformatted and install a new one. I installed GoAutoDial CE 2.1. I was told that both network cards was used. I have configured eth0 with local settings and eth1 for public. Both are working but I have to type ifup eth1 every time I turn it on or restart. But even with eth1 disabled it is working. So I just left it as it is.

I want to understand what is the use of having two network cards? I also want to utilize both cards.

[Rudolfmdlt]

Hi jdk85,

A NIC is a tool - either you use it because you need it or you don't. There are hundreds of scenarios. One setup could be that you server has a LAN interface to talk to LAN phones and Dials out of a PRI card. Or that your server has a LAN interface and your outbound SIP goes through a router on your LAN so local and external calls all appear on-net to the server. I have a setup with four NICS, one for LAN and the other three each go to a dedicated ISP for VoIP. If your system isn't broken don't try to fix it! Maybe draw up a network diagram of how you think it should look and post it here?

How did you configure the nic? I have never used GoAutodial so not sure f there is a tool included to make configuring network cards easier. What command did you run to configure the nic?

This might help: "How to configure static ip on centos"
https://gist.github.com/fernandoaleman/2172388
http://www.centos.org/docs/5/html/Deplo ... faces.html

the specific one you are looking for I believe is onboot=yes.

Regards,

Rudolf

[jdk85]

Ok let me illustrate the current network diagram.

I have one server that has two NICS, eth0 and eth1. First eth0. eth0 has a static ip for local. It is connected to a local router. The router is also used to connect the other LAN computers used by agents to call. The router is connected to a switch which is connected to the modem.

eth1 has static ip for public. It is connected directly to the switch. I don't know how to do this but I will try to draw a summary:

server > eth0 > router >
--------> eth1---------- > switch > modem

There is no problem with the configurations I have placed. Agents can connect to the server through eth0 and make calls. I can also access the server using the public ip of eth1. Maybe my question is: why does my server has two network cards? If my boss ask me this question, I can't give him a good answer.

I am interested on understanding why did you use four NICs.

[Rudolfmdlt]

Hello JDK85,

I think you confused switch and router.
http://compnetworking.about.com/od/home ... switch.htm
http://ccna-guidance.blogspot.com/2010/ ... dcast.html

You can't connect a public IP to a switch, behind a router.
The above links are just posted for your interest.

Your LAN is for all devices on your LOCAL AREA NETWORK (Agents, Phones, PC's and of course your Server). All LAN devices plug in to a SWITCH. The LAN devices break out to the internet through the router (Your default gateway in windows).

So you can have Vicidial through to the agents on the LAN and dial out to the internet with just one NIC. Voice will flow from the Vici server, to the switch, through the router and out to your provider.
Agent -> Switch -> Vici Server -> Switch -> Router -> Public WWW ISP

The problem is that without very special routing and QoS on the router, your voice will share bandwidth with data and you can have bad voice quality. Your email, downloads and voice will all go over the same line.

It is much easier to take a cable directly to the router and give your Vici server's voice traffic a direct "private" route for the voice so that the voice does not have to compete with the data.

This is one reason, giving voice dedicated bandwidth for guaranteed quality - there are many others. I hope that gives you an answer for your boss.

Rudolf

[jdk85]

I see. I understand your explanation. Thank you Mr. Rudolf.

Yes. I was confused with my post earlier. I forgot I have a router after the modem.

server > eth0 > router >
--------> eth1---------- > switch > router > modem

My apologies to my earlier post. I grouped the modem with the router connected to it because it was provided by the ISP.

We were given public IPs by the ISP. So, a public IP was assigned to the router in which eth0 is connected and another public IP is assigned to eth1 of the server.

I'll get back to this after the weekend.

[williamconley]

the purpose of two network cards is simply to allow internal communications with other local servers/agents on a trusted (and usually faster) network without bothering with security.

if you use iptables (with or without a package like fail2ban), your iptables system can be set to ignore the local network completely. this speeds up communications on that network as there is no package "checking" the incoming communications on that network. additionally, it is common for the servers in a local network to share a Gigabit switch for inter-server communications at high-speed (impossible on the public network unless you have google fiber).

the public ip would then have iptables (or another security package, or a router) and be "secure" as a result. no need for security on a trusted network.

also, for telephone systems, NAT can be turned off on all audio channels on the local network. a technical difference, but necessary in some cases.