Topic: sme 7.5 in server-gateway mode not connecting to internet

[gabby]

Hello All,

I have been battling this for over a week and can't figure out what has changed that my setup no longer works.

My network appears as such:
Internet---Cable Modem---SME---Switch---Clients

I get a dynamic IP address from my ISP. The Cable modem is a UBEE DDW3611 configured in Bridge Mode, so the routing functions are disabled and the modem passes the external IP address through to the external nic on SME.

I have successfully run in this configuration for 3 years. When ever the ISP chooses to change the IP address, I've had a temporary outage, but have always been able to recover by manually forcing SME to update the external IP address and then changing the settings at DynDNS.

I was able to test the server in a completely different network and was able to bring it online again with very few issues. When I placed the server back into its native network, I continued to see the failure to connect to the internet.

With the modem operating in Bridge Mode, there aren't really any settings that I can tweak. When I connect a Windows client directly to the modem, I instantly get an external IP address and have internet connectivity.

Any help here would be greatly appreciated.

Best regards

[gabby]

Well, my brother and I have meticulously walked through the settings in both the modem and SME. Unbeknownst to us, something we have done now has SME working as it has for the last 3 years.

We are still bringing the internal network back on-line and verifying connectivity through the server.

Any thoughts on what caused this problem in the first place would be greatly appreciated, this won't be the last time that my isp decides to renew our ip address.

After this outage, I am seriously considering the extra fee for a static IP address.

Thanks.

[janet]

gabby

..... I continued to see the failure to connect to the internet.

Exactly what failure is this ?
Where/when do you see it, what error message etc etc.
Also more details of your configuration setup (from the admin console -Configure this server screen).

Have you tried swapping the NIC cables and run the Internet connection test in admin console ?

[gabby]

mary,

There was no error message, the failure to connect was observed from the "Test Internet Connection". It was simply reporting that the connection failed.

I have SME setup for server-gateway mode, DHCP from the ISP (option 2), internal ip address range is 192.168.1.xxx, and I use dyndns to manage the dns servers. SME gets the external ip address directly from the modem which is configured in bridge mode.

The last time that the ISP changed the IP address, SME failed to update the external address, the DNS servers didn't get updated and all attempts to force the external IP address to change (using /sbin/e-smith/signal-event ip-change nnn.nnn.nnn.nnn) did change the external IP address (according to ifconfig), but the server continued to fail the internet connection test.

The network is back up and running until the ISP decides to change our IP address again. I am just looking to understand what the potential causes of this situation may be so that I can try to narrow in on a solution faster the next time it occurs.

I am an electrical engineer by training and practice. I have limited exposure to Linux distributions and their management. A friend helped us set up this network initially, but is no longer in the area to help, so I've been learning the basics along the way.

Thank you for your help.

[mmccarn]

There have been some bug reports about the network cards being "swapped" at reboot.  Even though most of these are now 'status: resolved-wontfix' or 'status:resolved-worksforme', if you aren't up-to-date on your patches, you may want to catch up.

I'd also recommend testing your internet connection with another computer if the problem comes back -- believe it or not, I've seen ISPs that have actual problems that they won't admit to...  It seems possible to me that your ISP had a hiccup. 

It sounds like you should be able to do this by plugging the WAN cable into one of your LAN workstations. 

If you do try test using another computer, be aware that the ISP may have settings at their end that depend on the MAC address of the system connected.  I've been told by Comcast here in the Washington, DC area that their switches have a 120 second timeout on the MAC address cache - and that if I need to change the computer connected to their modem I need to power down the modem for at least that long (120 sec) in order to force their remote switch to reset the port connected to my modem.

[janet]

gabby

I use 5 minutes as a standard time to shut down modems before restarting them, in similar situations.
I would also power down the sme server at the same time.

Have you configured the dynamic DNS updater settings in the Configure this server steps, ie put in your dyndns account name and password for the main dyndns domain that your server uses ?
It should update the external IP address automatically at dyndns whenever your ISP issues a new address.

[CharlieBrady]

The network is back up and running until the ISP decides to change our IP address again. I am just looking to understand what the potential causes of this situation may be so that I can try to narrow in on a solution faster the next time it occurs.

The way to do that is to report full details of your problem via the bug tracker.

[aussierob]

There have been some bug reports about the network cards being "swapped" at reboot.  Even though most of these are now 'status: resolved-wontfix' or 'status:resolved-worksforme', if you aren't up-to-date on your patches, you may want to catch up.

Hi folks,
I have a SME7 in Server/Gateway mode- used mostly for LAN terminal access to an application and email serving.

Another person has put a Microsoft box on the LAN  to take over mail, web, printers
and now suddenly the SME cannot access the internet.
(I cannot ssh to it - the server manager settings are correct, and the 'test internet connection' fails).

I am wondering if your comment above is an issue, and if not any other advice would be appreciated -
I am thinking I change it to 'server only' but as the machine is 1000miles away I do not want to muck up!
(I do have remote access to the microsoft box, and can run putty on that to login on the LAN)

Oh, yes - the SME will simply be the application server now with me having external ssh and ftp access.


TIA Robert

[janet]

aussierob

'test internet connection' fails

I assume this test was run at the sme server console.
It sounds like your sme server is no longer acting as the gateway
If that is the case, then you would need to run Configure this server and specify the IP of the new gateway so the sme server can have Internet access via that gateway.

It would also imply that you should change the server mode to Server only (at the same time as when doing Configure this server)
You would need to forward ports eg 22 or 2222 for ssh access from the new gateway to sme. Same for any other services on the sme server ie ftp.

[Stefano]

Another person has put a Microsoft box on the LAN  to take over mail, web, printers
and now suddenly the SME cannot access the internet.

I suspect the windoze guy did something more than "put a M$ box"..

is SME reachable from lan?
are you sure there are no other changes (router, portforward etc)?

[aussierob]

is SME reachable from lan?
are you sure there are no other changes (router, portforward etc)?

Thanks to both Stefano and Mary for the help.

1. The SME is reachable from the LAN by the putty (ssh to the sme) still being used for the application after the new box install.
2. Yes Mary, the internet test was run at the sme server console (me remote connected the microsoft box, putty to the SME logged in as admin).
3. Mary's reply seems to be the way to go (I agree with Stefano - no doubt the router has had firewall rules added to it:
it also forwards ssh to the SME LAN-IP)

So to be sure I have this correct
a. run Configure this server to specify the IP router as the gateway and change its mode to server-only.
 so the sme server can have Internet access via that gateway.
b. in the router that I set the Inbound services for ftp and ssh 'always allow' to the SME IP
(its a netgear router and I know how to do that)

Thanks again for the generous help - normally I would just 'play' with it, but I do not want to get locked out or muck something up at this distance
(I may still be cautious and do it midday Sat - then I will have until Monday morning to get there and fix any disaster)

Kindest Regards
Robert