Topic: Strange DynDNS client behaviour.. (kinda OT)

[boss_hog]

Hey Yall,
I am raising the question about the function of DynDNS client specific to SME. When the server is set to Server/Gateway it obtains a NAT'ed address from my ADSL modem. In other words, my public ip is 123.123.123.123, but the IP that is given to the SME is 123.123.123.183.

So when the built in software for the DynDNS client checks the IP, it acquires the incorrect public IP(123.123.123.183) which takes my server etc. "off-line". Now for the curveball in this picture, if I connect my Linksys router/AP to the ADSL modem it WILL obtain my public IP address.

Also for the record, ALL of the Linux distro's that I have tested, do the same thing: Mono-wall, Smoothwall, ClarkConnect etc.. So I don't believe this is a specific problem with SME, but I am unable to use the SME to its fullest extent. I would like to utilize the Port Forwarding features in the SME. The Linksys only has Port Ranges which is not what I need.

According to the tech. people of my ISP, the portion of their network my system is on, is not PPPoE or PPPoA, some technical issue in the area I reside(?) that they can't use it. My connection does NOT require any log-in information from my end, they use the MAC on the modem and the phone number for user verification.

I am throwing this out to the community for any suggestions or input as to why or what is causing this anomoly. Any and all input would be appreciated.

As a side note: the Linksys router does use a GPL firmware, running Linux kernel. Inside the web interface there is a setting that lets the user select router or gateway mode for the Linksys.
Thanks
Joe

[gordonr]

Hey Yall,
I am raising the question about the function of DynDNS client specific to SME. When the server is set to Server/Gateway it obtains a NAT'ed address from my ADSL modem. In other words, my public ip is 123.123.123.123, but the IP that is given to the SME is 123.123.123.183.

OK - when you get that IP address, presumably via DHCP, one of the scripts in /sbin/e-smith/dynamic-dns is called with the post-NAT IP address as a parameter. What your setup requires is the pre-NAT address. That's not currently catered for, but read on...

As a side note: the Linksys router does use a GPL firmware, running Linux kernel. Inside the web interface there is a setting that lets the user select router or gateway mode for the Linksys.
Thanks
Joe

The Linksys firmware is somehow determining the pre-NAT/public address. There are quite a few ways to do that, but you need to talk with something outside your network.

Have a look at ez-ipupdate. There was a HOWTO available:

http://no.longer.valid/phpwiki/index.php/How%20to%20implement%20easyDNS%20dynamic%20DNS%20service

It might make a lot of sense to replace all of the oldish dynamic DNS scripts with configuration for ez-ipupdate.

Feel like raising that in the SME 7 bug tracker?

The better option, if you can, is to disable NAT in your ADSL modem, by configuring it in "bridge" mode.

[boss_hog]

Hey Gordon,
after I have SME7b5 (yehhaaa) installed I will raise a bug if the issue is still there!

Yes, setting the ADSL modem to bridge would probably help or stop the problem, I will see if I can change the configuration.

The Linksys firmware is somehow determining the pre-NAT/public address. There are quite a few ways to do that, but you need to talk with something outside your network.

The confusing part of this picture: if you use the check.dyndns.org test page from a workststion behind the SME Gateway, it will show the ACTUAL public IP. However, when the check IP cron job runs for the DynDNS client, it gets the incorrect IP of the server(?).

Okay, I have beaten up this subject pretty good.
Thanks
Joe

[gordonr]

Hey Gordon,
after I have SME7b5 (yehhaaa) installed I will raise a bug if the issue is still there!

It will be - nothing has changed.

The confusing part of this picture: if you use the check.dyndns.org test page from a workststion behind the SME Gateway, it will show the ACTUAL public IP. However, when the check IP cron job runs for the DynDNS client, it gets the incorrect IP of the server(?).

No, that's not confusing at all. The check.dyndns.org page is looking at the source address of the connection which is the pre-NAT (external) address.

Our current dyndns client is being provided with the post-NAT (internal) address by the modem, and it is providing that as the address when updating DynDNS. That won't work in a NAT configuration such as yours.

[sits]

Hi Boss

I also have had some problems with dyndns

I now use NO-IP they have a pretty good linux client that runs well in all versions of SME, a free account is available, and under FAQ there is a howto for linux

I have it running on several servers now

you can check it out at

http://www.no-ip.com/

just register and away you go