ADSL and Linux *with* PPoE

[Deckert]

Hi y'all,

I'm getting an ADSL link installed in a few weeks' time (after reading the mywireless forum), but I am currently connected to the office via a dedicated leased line and have one static IP on my Linux box. This has worked wonderfully for me over the past 5 years.

I've read through a couple of toppics on this forum and I've found some information as to which ADSL router/modem to get.

From what I can gather, the Telkom unit is a no-no.

Good units seem to be from D-Link, Netgear, Planet and SMC. (Oviously a Cisco unit will also be good, but way out of my price range).

Now, many have recommended a router with built-in NAT, firewall and so on. The thing is, I want my *linux box* to have the routable IP. I want to be able to use iptables to forward stuff to the inside and prioritise my timing traffic.

So, I guess I'm asking for advice on the best ADSL/PPoE modem out there. One that I've heard of is the D-Link DSL300G. What other *reliable* devices out there support PPoE in such a way that I get my IP allocated to my Linux box, and not some silly router in front of it with no intelligence.

Thanks!
--deckert

 

[podo]

You don't need to look any further than the D-Link DSL-300G. I should start out by saying that it's NOT a router, but that isn't really what you want, so that's a good thing. The DSL-300G acts as a simple ethernet to ethernet over ATM bridge, providing a physical connection to the ADSL network, but nothing more. The DSL-300G is extremely reliable and the performance I get from this device is stellar.

My IP connection is maintained by the userspace ppp(8) program on FreeBSD, using the NETGRAPH_PPPoE module. The FreeBSD box used to be the router for my analogue leased line connection. After connecting the DSL-300G to the switch, all I had to do was set up the FreeBSD machine to use the ppp(8) client with NETGRAPH_PPPoE, instead of the old pppd(8) which was operating the leased line, and everything worked just fine.

In your case, the DSL-300G with the Roaring Penguin PPPoE client on the Linux machine will do the trick very nicely.

Of all the units on the market, the DSL-300G offers the best value for money, in my opinion. It should retail around R750. The boxed set includes a telephone cable, the obligetory transformer, manual, CD with software to controle the modem via SMNP on Windows, a straight wired ethernet cable, for connecting to switches, and a cross-over wired cable for connecting directly to the ethernet port on a PC.

In addition to the Windows SNMP software, the modem can also be operated via SNMPv1, telnet and an extensive web interface.

NOTE: I am not at present, nor have I been at any time in the past, affiliated with D-Link or D-Link S.A. in any way. My recommendation is based purely on my experience with the product.

Willie Viljoen
Web Developer

Adaptive Web Development

 

[Deckert]

Thanks for the info podo.

If the DLink DSL-300G is used in PPPoE mode, how do you telnet to it? Does it get another IP for the management interface?

Is this the only device out there that has this ability? I'm more or less sold on the DLink, but my training forces me to always investigate other options and make an informed decision based on much more data.

(okay, yes, yes, I'm taking it to the extreme, I know!)

--deckert

 

[podo]

Deckert,

Well, technically it would be running in bridge mode, as all it is doing is providing a physical layer link between your ethernet and the virtual ethernet layer on the ADSL network, but yes, the modem must be given an address on your internal network to be able to manage it. The address is management only though, you can't use it as a router or DNS server, or anything other than a management, for that matter.

I'm pretty sure that quite a few of the devices on the market can do this. All of the routers I have come across can be configured not to route, in other words, to act as bridges, but buying a router if all you need is a bridge is overkill, since you'll be paying an extra R1000 or so for functionality you don't really need.

As far as I know, the DSL-300G is the only pure bridge type modem that's sold in S.A.

Willie Viljoen
Web Developer

Adaptive Web Development

 

[loosecannon]

set up in bridge mode the netgear has worked very well for me the next trick is to set up ppp 2.4.2 [rp plugin already shipped with it].

here follows a options file i use that also allows dial in/out/multilink [ISDN] with RAS/radius
----
multilink
endpoint MAC:eth0
nobsdcomp
nodeflate
maxfail 0
noipdefault
holdoff 10
ms-dns 10.10.255.1
ms-wins 10.10.255.1
-----
the command i use to connect to sentech/ADSL
/usr/sbin/pppd sync plugin rp-pppoe.so eth1 unit 0 mru ** mtu ** linkname
main user ***** defaultroute noauth persist nomultilink

this creats a sync connection on eth1 always named ppp0 correct MTU/MRU names the link main [script to test if it is up runs from cron] ...

of course you need a pap/chap secrets file

there a cpl goodies you can put in /etc/ppp/ip-up to allow dynamic dns updates/access to SSL sites bypasing the proxy/access to STD bank [same prob lem as SSL sites]/firewalling ....

if you not going to use RAS the commandline options can be put into the options file things like unit/linkname/multilink/dns/wins/endpoint/holdoff are possibly not needed

i run the pppoe-server on my eth0 to allow access to the system via radius in a wireless hotspot config DHCP with host entries/MAC addresses is also supported ... so it gets a bit complex

 

[Deckert]

podo, thanks.

D-Link's customer service/sales reminds me somewhat of Sentech's (i.e. it 'sucks'). I've mailed them without any response. I waited, time passed, nothing happened. After a call to them, they could not find somebody to help me nor point me to a reseller where I could find the 300G.

So I am investigating the netgear range, and also the Planet ADSL router/bridge. It costs R695.00 (ex), but nobody is interrested in using it in bridging mode and consequently they have no experience with it in that mode.

"..stuck in the middle with you..."

--deckert

 

[Deckert]

<i>Originally posted by loosecannon:
set up in bridge mode the netgear has worked very well for me the next trick is to set up ppp 2.4.2 [rp plugin already shipped with it].
</i>
I've seen the roaring penguin stuff work well with Sentech's offering so I'll give it a go, but I'm going to try the new PPPoE extentions in the Linux kernel, which is still experimental, but supports PPPoE natively alongside pppd 2.4.2. I'll let you know how things go with it.

--deckert

 

[loosecannon]

hi there deckert that is what i was refering to sorry i was not more clear on that ... it works fantastic on linux 2.4 and 2.6 for both sentech amd telkom.

i try to keep things simple and having to run software like RP when it is not required is pointless.

all the best ... contact me if you need anything ...

TTFN

 

[podo]

Deckert,

Sadly, you won't get much from D-Link in that regard, since their staff seem to be trained to give you the brush off if you aren't phoning from a very large reseller. Try giving your local retailer a call, then they will call their local reseller, who will call D-Link. Of course, all of these will add their little "commission" to the price. []

Willie Viljoen
Web Developer

Adaptive Web Development

 

[infrabyte]

Hi

First of all there is nothing wrong with the telkom pots router...maybe over priced but hey so is everything. I've been using this 'klunky' old router ever since telkom started with adsl and I've used it to vpn, ftp, telnet & ssh into my linux box and have never had any problems. From what I see here, not much experience or reserch. Don't listen to everything you hear or read. A servey last week proved that 67% of what you hear or read is fiction or idle chat.

You need to play around prove things for yourself to make a decent comment.

Infrabyte
Linux Net Admin

 

[Deckert]

Agreed: don't believe everything you read/hear, but it depends where you read it and who you hear it from. I got my info from three friends that I highly respect in the IT industry. They all maintain high-availability systems and have diverse backgrounds and likes in OS (i.e. Windows, MACs, Linux). All three told me they wish they'd never gone with the Telkom devices since they were not very stable and had problems with certain types of network cards in terms of negotiating protocol (framing, speed, duplex) when used in PPPoE mode.

Now, they all got their ADSL installations early on, and admittedly received early implementations of these devices, but I'm still weary.

In any event, I managed to get the DSL-300G for R570, ex VAT from a Centurion supplier, so in the end I have the best of both worlds - reliability and good price.

Thanks for the pointers/help so far guys.

--deckert

 

[Deckert]

Hi,

Just a quick update on the D-Link DSL-300T (yes, T, not G). It seems that the 'G' model is no longer made or supplied by D-Link SA. Instead I received the 'T' model.

It is completely different from the 'G' model. I was disappointed when I saw that it had no SNMP support, but things are looking up

The new device can act as a bridge (like the G) but it also has a NAT/Firewall mode with a built-in DHCP server. The best part is that the T is a mini-linux box. It runs Linux kernel 2.4.17 (2.4.17_mvl21-malta-mips_fp_le) on a MIPS processor. You can telnet to it and it acts like a mini floppy-fw. Hardware-wise it seems to have about 6.5MB RAM and 2MB flash-ram (from whence it boots).

It even has iptables on it, and you can manually add/change iptables rules. Still figuring out how the XML config file works, but so far I am very happy with it.

I am, however, still waiting for Telkom to come install my ADSL line, so I cannot comment on performance just yet, but I have no doubt that it will fly - seeing the platform it's built on.

--deckert