Topic: ADSL connectivity

[RickJones]

I'm trying to work out what support there is in SME 8 for non-routed connection to an ADSL line (UK).

I'm currently still running SME 6 on an old (antique? but very reliable machine. This is mainly  because I have a Traverse Pulsar ADSL PCI card for the ISP connection. I built the Traverse drivers, and configured it to emulate a dial-up modem. This works well, and with a static IP, SME supports incoming connections with no trouble, including VPN.

Upgrading this even to SME 7 would have required changing the driver architecture etc. for the Pulsar, which I've never bothered doing: "if it ain't broke don't fix it"!

But there are now just too many out-dated things in SME 6, so I've finally decided to get a new box and install SME 8. But I'm not going to be able to use the Pulsar (only PCIe slots), and I want to avoid custom devices anyway. I'm kinda hoping that I can get a USB ADSL modem that SME will support, ideally by seeing it as a dial-up modem, but I see nothing documented to suggest I can do this. Is it possible?

AFAICS the only other option is to use a router configured in pass-through mode, which will mean adding a net card to get a 2nd ethernet port. Does a configuration like this place any constraints on incoming connections (http(s), ftp, smtp, ssh, vpn, etc)?

TIA for your help.

Rick Jones

[Curly]

I'm using a ADSL-modem-router in bridged mode (SIP-SPOOF), and before that I had a pppoe connection via dial-up. Have been using bridged mode since 2003, never a problem.

- edit:
I have an extra command in /etc/rc.d/rc.local

ifconfig eth1 <outside ip-adress> pointopoint 10.0.0.138 netmask 255.255.255.255 broadcast 0.0.0.0

[byte]

I'm kinda hoping that I can get a USB ADSL modem that SME will support, ideally by seeing it as a dial-up modem, but I see nothing documented to suggest I can do this. Is it possible?

Official line is USB Modems are unsupported.

But it might be able to "get it to work" by configuring for a standard dial up and then typing:

config set DialupModemDevice /dev/usb/ttyACM0
signal-event post-upgrade
signal-event reboot

If you do try could you let others know the result of your tests.

Thanks.

[CharlieBrady]

Do you have good reason to not spend $10 on a second NIC and use pppoe with an ethernet ADSL modem?

[RickJones]

Do you have good reason to not spend $10 on a second NIC and use pppoe with an ethernet ADSL modem?

Not begruding the price of a NIC. However, in the UK we use PPoA with ADSL, and there's no such thing as an ethernet modem for it. The only ADSL devices with ethernet ports are routers, which seems to make things a bit different from the way it works in the US.

In most routers you can configure what they laughingly call a DMZ host, which is actually just an exposed host - all incoming traffic is port-forwarded to it. But the router will still terminate the link, handle the local IP and DNS address assignments, and NAT all the traffic.

I'm just a little unclear as to whether SME will operate in that mode with all the same functionality as when it directly controls the link.

Rick

[janet]

RickJones

Search the forums on PPoA as there have been a few posts (in the last year or so) that detail how to set it up. SME has a configuration mode for that ie "static IP" or something like that. Yes the router will have to handle many of the gateway tasks.

[NickR]

RickJones

I think you are a bit confused about how UK modem/routers can be configured to work with the SME.  You have several options (but obviously a fixed external IP is a pre-requisite unless you want to trust the vagaries of dyndns):

1) Use an ISP who will allocate a range of public IP addresses - easy to configure the SME with this.  A few I have used: Zen, BE, Demon, Easynet
2) With a single IP, use the router in bridge (non-NAT) mode - the trusty old DG834 supports this
3) Go with DMZ but treat it as a standalone interface to the internet.  You will configure your second NIC to talk to the router over (say 10.10.0.x) & your first NIC talks to your LAN as normal.  Turn off DHCP & the firewall on the router and let the SME take care of everything coming in from the outside world.

I've used all 3 methods, but method 1 is by far the most intuitive.
 

[RickJones]

Hi NickR

Yes, I am a bit confused - hence the questions.

Your method 3 is what I had in mind, it's reassuring to know that it works OK. What about DNS servers? Is it just a question of manually inserting the ISP's DNS server IPs into SME's config?

I'm not sure if I have a router that does bridging, I'll have to check. It looks like that might be a simpler setup, I hadn't really appreciated it could be done this way. What about the DNS server question in this configuration - same as above?

Thanks, Rick

[NickR]

There's no reason to use the ISP DNS servers - they are generally a much poorer alternative to letting the SME query the root servers.  The only reason you might want to use the ISP servers is if they block you doing your own DNS queries on the root servers but I'm not aware of any UK ISP that does this. In other words, don't put anything in the DNS server page of the SME and it should all "just work".