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-   -   ADSL modem - Router or Bridge? Linux server present. (https://www.linuxquestions.org/questions/linux-networking-3/adsl-modem-router-or-bridge-linux-server-present-834259/)

felipefv 09-24-2010 09:06 AM

ADSL modem - Router or Bridge? Linux server present.
 
Good morning. I wonder what is your opinion about the best method for using an ADSL modem, considering that I have a Debian Linux server working here (PC - Intel Pentium IV 3,06 Ghz, 2GB RAM), and can use it as a router. My network has 6 computers with high traffic.

So... Router or bridge?

I did read some articles that say "that the bridge mode gives you more stability and has higher speed". Is that true?

Furthermore, you suggest any alternative to "pppoeconf"? I've been getting this errors ( in the plog), related to "PAD packet loss" and also errors in "PPPOE Discovery", even when I am connected. When this things starts to show up on the log, my connection "pauses" for some seconds. I do not feel very safe with this program.

Thanks for all!

catkin 09-24-2010 10:55 AM

Advantages of using the ADSL modem as a router:
  • Better security from the NAT and firewall features.
  • Easier administration from having the Internet access functionality in a single device instead of spread across two.
  • Greater availability -- Internet access works when the server is unavailable (during upgrade or hardware failure) instead of when either device is unavailable.

I don't know about stability and speed.

felipefv 09-24-2010 01:30 PM

catkin,

Thanks for the reply!
Yes... we have to do some tests, but I think that a better question is: does the server that I have here will do a better job than the modem in router mode?

I have 6 PCs on my network, with high traffic.
Server config: PC - Intel Pentium IV 3,06 Ghz, 2GB RAM.

catkin 09-24-2010 02:55 PM

Only tests will tell but it seems likely that the ADSL modem's dedicated hardware designed specifically for its job will do better than the server's general purpose hardware doing the same job, especially if the server is loaded.

slac-in-the-box 09-26-2010 03:35 PM

do you have a static?
 
I had to put my adsl modem in bridge mode in order to use static ip addresses from my ISP.

janhe 09-27-2010 03:30 AM

It really depends on your modem. As long as it doesn't crash because of the many connections (speed is not so much an issue, it is the NAT that really eats processor time/memory), you are better of with the modem as a router.

If you are having problems with the modem, or if you want a public IP on the server, then you should use bridged mode.

felipefv 09-27-2010 08:46 AM

Quote:

Originally Posted by slac-in-the-box (Post 4109651)
I had to put my adsl modem in bridge mode in order to use static ip addresses from my ISP.

I understand. But what program/app do you use to connect to your ISP? Pppoeconf? Do you get any errors?



Quote:

Originally Posted by janhe (Post 4110028)
It really depends on your modem. As long as it doesn't crash because of the many connections (speed is not so much an issue, it is the NAT that really eats processor time/memory), you are better of with the modem as a router.

If you are having problems with the modem, or if you want a public IP on the server, then you should use bridged mode.

janhe,

Well... sometimes we have to reboot it. I think it is crashing.
And do you use the modem as bridge and connect via linux with pppoeconf?

slac-in-the-box 09-27-2010 12:42 PM

Quote:

But what program/app do you use to connect to your ISP? Pppoeconf? Do you get any errors?
The modem, in bridge mode, needs no further configuration. The modem, in bridge mode, does not actually connect to my ISP, but just extends my ISP's network, such that plugging in an ethernet cable to the modem is like plugging it in directly to my ISPs subnet.

Don't really need a special program to connect. I just configure the interface on the computer that connects to the modem to use the static ip provided by my ISP.

Since I am using linux, I use the following command to configure my eth0 interface:

Code:

ifconfig eth0 inet ##.##.##.## netmask 255.255.252.0
(of course, I replaced the actual numbers of my public ip address with number signs for privacy concerns).

Once the interface is so configured then it is connected, and it can ping out to my ISP's nameservers, etc.

janhe 09-28-2010 04:46 AM

Quote:

Originally Posted by felipefv (Post 4110295)
...
Well... sometimes we have to reboot it. I think it is crashing.
And do you use the modem as bridge and connect via linux with pppoeconf?
...

I use my modem as a router. I have succesfully used the rp-pppoe package to make a connection.
I'm not at my laptop right now, but if I remember correctly, I had to use pppoe-setup to enter my credentials, and pppoe-start to make a connection.

That being said: there are 3 ways ADSL providers can provide a connection.
- PPPoE (the way you are looking at, also the most common)
- DHCP (less common)
- PPPoA (older, also, it requires your modem to be the router)

Do you have some documentation from your ISP that says you need to use PPPoE? Or have you deducted that from your modem setup?

felipefv 09-28-2010 08:56 AM

Quote:

Originally Posted by slac-in-the-box (Post 4110512)
The modem, in bridge mode, needs no further configuration. The modem, in bridge mode, does not actually connect to my ISP, but just extends my ISP's network, such that plugging in an ethernet cable to the modem is like plugging it in directly to my ISPs subnet.

Don't really need a special program to connect. I just configure the interface on the computer that connects to the modem to use the static ip provided by my ISP.

Since I am using linux, I use the following command to configure my eth0 interface:

Code:

ifconfig eth0 inet ##.##.##.## netmask 255.255.252.0
(of course, I replaced the actual numbers of my public ip address with number signs for privacy concerns).

Once the interface is so configured then it is connected, and it can ping out to my ISP's nameservers, etc.

The problem is that my ISP don't work this way. We have to log in, in order to get and IP address. So this is why I need the pppoeconf app.



Quote:

Originally Posted by janhe (Post 4111207)
I use my modem as a router. I have succesfully used the rp-pppoe package to make a connection.
I'm not at my laptop right now, but if I remember correctly, I had to use pppoe-setup to enter my credentials, and pppoe-start to make a connection.

That being said: there are 3 ways ADSL providers can provide a connection.
- PPPoE (the way you are looking at, also the most common)
- DHCP (less common)
- PPPoA (older, also, it requires your modem to be the router)

Do you have some documentation from your ISP that says you need to use PPPoE? Or have you deducted that from your modem setup?

Here we have to connect via PPPoE. We have to log in with an username and a password. This is why I'm looking for an app that can do that for me. I know about "pppoeconf", but I'm getting some errors related to "PAD packet loss" and "PPPoE Discovery" (even when I'm connected). I don't know if this is normal...

slac-in-the-box 10-02-2010 12:41 AM

Well, I found an app called pppoe that was already installed on my system:

Code:

firebolt% which pppoe
/usr/sbin/pppoe
firebolt%


And then I typed "man pppoe" to learn how to use it, and the following except was displayed:

Code:

NAME
      pppoe - user-space PPPoE client.

SYNOPSIS
      pppd pty 'pppoe [pppoe_options]' [pppd_options]

      pppoe -A [pppoe_options]

DESCRIPTION
      pppoe  is  a  user-space client for PPPoE (Point-to-Point Protocol over
      Ethernet) for Linux and other UNIX systems.  pppoe  works  in  concert
      with  the pppd PPP daemon to provide a PPP connection over Ethernet, as
      is used by many DSL service providers.

Maybe same program is already installed on your linux server ?

felipefv 10-07-2010 11:33 AM

slac-in-the-box,

Sorry for the delay in replying to the message.

Well, searching on the internet forums, I verified that using a good router (like Cisco/Linksys) is the best option. In the case of larger networks (like in large corporations), then it might be interesting to use a dedicated PC server as a "router". In relation to how to use the modem, it would be interesting to split tasks between two devices (modem and routing), and that is what I am doing right now, and it is really good.

Modem: Huawei SmartAX MT880A
Router (wireless): D-Link DI-524

I think that I will keep this setup.

I would like to thank you all!


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