[Outages-discussion] [outages] UK wide DSL broadband outages

[Colin Johnston]

On 21 Oct 2011, at 15:06, Paul Lettington wrote:

> On Fri, Oct 21 2011 08:10:02 -0500, Frank Bulk wrote:
>> Why did a 15-minute outage cause subtended customers to be out for much
>> longer than that?
> 
> Because BT's RADIUS servers which look at the realm of the login and route the
> session to the correct ISP are unable to cope with the load of all the ADSL
> users in the country continually reconnecting during an outage like this.
> 
> So when BT can't connect the end user to the ISP they accept the end user's
> session themselves with a RFC1918 IP address for exactly an hour and not
> connected to the internet, to stop them trying to log in.
> 
> In today's outage, even though connectivity from BT to the ISPs had returned
> within 15 minutes, users who didn't reboot their routers or force a new login
> were stuck on the holding sessions until the hour expired. Also the sudden load
> of reconnections exactly an hour after the outage started meant that BT's
> RADIUS servers still couldn't cope, and put most of the customers back on a
> holding session for a second hour.
> 
At least from manchester uk the above did not happen correctly.
I did not see any rfc1918 wan ip allocated today, wan zyxel side never was allocated a ip so defaulted to 0.0.0.0
Only a forced adsl line reset solved and helped with manual allocation of static ip for route ip range

Colin Johnston