DSL Modem Failure, Downtime

Atypically, I host this Web-site on my private server at home. When I got home today, I found that the DSL Modem / Router, which I rent from my ISP, had gone into a partially failed state, in which WAN access was still ‘normal’, but where attempts to obtain new IP addresses were not succeeding – i.e. My smart-phone could not connect to my WiFi when I got home. Also, maintenance access, which has only been enabled from within my LAN, did not succeed to check the router status.

The only solution I could think of, was to unplug the modem, wait for 60 seconds, and then plug it in again. This seemed to work, and my maintenance password to the Modem / Router has not been changed. I.e., I was not hacked. I was able to log into the Router again.

But power-cycling a router like that causes the network (LAN and WAN) to be unstable for several minutes. As a consequence, my site, and this blog, were not visible to the Internet from about 13h05 until 13h20.

I apologize for any inconvenience.


P.S. Also, I now have a new, dynamically-assigned IP address. But this could be routine, as my domain-name should resolve to the new address anyway.

(Edit 09/11/2016 : ) I gave the command at 13h16 the same day, to propagate my new IP address, and my own router, acting as my DNS server, reflected the new IP address, still within 13h16. It should not really have taken most readers until 13h20, before their browsers would have been able to fetch my URLs again.


A Peculiar DNS Look-Up Error Has Affected My Site.

One of the facts which I had written about earlier, was that I host my site on my own Web-server at home, but that I am a client at DynDNS. This latter service is one, which is supposed to resolve to my correct WAN IP address, at home, if a client computer executes the command

host dirkmittler.homeip.net

But unfortunately, starting from some point in time unknown to me, this look-up has returned an inaccurate IP address. This is going to have affected the visibility of my blog, since maybe August 20? I do not know of what use it will be to have my IP address registered, if the hierarchy of DNS servers does not reflect my real IP address.

This is even stranger, because the IP-address registered at DynDNS has remained correct, and has kept pointing to my home network.

The only thing I was able to do to correct this problem, was to log in to DynDNS, and to reset the information there manually.



This Time, a Routine IP Address Switch

This time around, my ISP made a routine switch in my home IPv4 address, which my DynDNS software was able to follow, without any intervention on my part. This Earlier Posting explained, that a switch can also take place, which the software fails to follow automatically.

And this time, I did need to update my IPv6 (Teredo) address manually. It is to be assumed that IPv6 address changes of my server need to be updated manually, as explained in This Earlier Posting.

Hence, since last night, my IPv6 was unavailable until 13h15 this afternoon.



Some Strange Malfunction on the part of My ISP

I do not own my own IP address. And this blog is not being hosted from an IP address I own, but rather from a personal IPv4 address owned by my ISP, which they allot me via standard DHCP protocol. Hence, my ISP is free to change my IP address, and to assign me a new one at any time, on the assumption that I only have an account for personal use.

When the ISP does this, I have software in place, that makes sure my domain names still resolve to the new IPv4 address, i.e. software which updates the DNS servers with my new address. I am a client of DynDNS.

But since last evening, there has been some unusual activity in this regard, in that my ISP did not only assign me a new IPv4 address, but did so roughly once per hour, until today.

While doing so only disrupted IPv4 access to my blog minimally, it did in fact disrupt IPv6 access to my blog. Right now I have updated my IPv6 address again manually, so that IPv6 access should be possible again.

But I do hope that this malfunction has now passed.