Paul McCormack’s Web Site

As mentioned in my last post, I have migrated from Optus ADSL to TPG Naked ADSL2+. I have had a few reliability problems with the connection dropping out regularly which compounded the DNS migration issues.

TPG recommended changing the DSL modulation type to G.dmt, however my trusty NETGEAR modem/router does not have an option for this. After a short search, I found an article on the Whirlpool forums that described how to telnet onto the device and change the settings. Reading all the way to the bottom, I found a gem about an unofficial release of firmware for the NETGEAR DG834 range from DGTeam.

You see, NETGEAR did a good thing a couple of years back when they released their firmware to the community under an open source licence. The good folk at DGTeam picked up the code and have fixed numerous bugs and added functionality. Uploading the new firmware was simple and it worked straight away.

The new code has a drop down box to change the modulation type to G.dmt. The router reconnected and has been solid ever since. It has even connected at a higher speed than with the automatic setting.

Another bonus seems to be that the Asterisk SIP trunk disconnection that was occurring when the WAN IP changed seems to be working OK now. Previously, every time the modem dropped the line, my two external SIP trunks would become “UNREACHABLE” until I rebooted the server.

Another success for open source thanks to the guys at DGTeam.

I have changed ISP from Optus Business ADSL to TPG Naked ADSL2+. There have been a few problems during the transition which have prevented a smooth cut over.

The main problem has been that my new static IP address has not been configured properly by TPG despite being informed of the new address 10 days prior to activation of the line. This has meant that my IP changes frequently and the DNS lookups for my servers was failing. My web sites may appear to be down and inbound email delivery was intermittent.

I tried to avoid this problem up front by adding the new static IP to my DNS records. This was cunning foresight, but the problem with constantly changing dynamic IP addresses messed things up.

I also made an oversight with the TTL (Time To Live) settings for the DNS entries. I left these as 1 week which was far too high long as this meant that an incorrect DNS lookup could have been stored for up to a week before being re-checked. I have dropped this to 30 minutes until the IP address allocation has been fixed.

Good job I don’t change ISP very often. Sorry if you were having problems accessing our web sites in the meantime, however my upload speed has increased fourfold from 256Kb to 1Mb so the sites should load a lot quicker.