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Re: What do you do when your Home ISP is down?
From: Alex Brooks <askoorb+nanog () gmail com>
Date: Thu, 18 Aug 2011 20:21:36 +0100

On Thu, Aug 18, 2011 at 6:21 PM, Mark Keymer <mark () viviotech net> wrote:

I am wondering what some of you guys do when your home ISP is down. At
least those of you that don't give yourself internet.

Ooh, heck.  I'm going through this at the moment.  I noticed a website that
doesn't load some of the time.  After a bit of digging, I discovered that it
doesn't load only when our ISP has given us an address in the 2.97 range,
but fine in other more 'normal' ranges.  Bit of digging later seemed to
confirm that a router 12 hops away in Cogent's IP space (38.*) in Boston is
replying with "destination net unreachable", or simply dropping the
connection on the floor.  So, looks like that router doesn't like previously
bogonised IP space.  Fair enough.

I thought I would actually give this to my ISP to fix, to see what would
happen, and used their online tech support forums to do this .  I reported
it last Tuesday, the 9th of August.  Acknowledged on the 11th of August,
given an incident number etc.  So, this Tuesday they reset the card in the
MSAN at the exchange, cutting all phone and Internet for 20 minutes.  After
a bit more of "the issue is still with Networks", as of today, we've got as
far as them asking if I use their DNS servers or someone else's.  I've sent
them the output of nslookup from their own, OpenDNS and Google, showing the
same IP response from all three.

We've even had confirmation from another subscriber elsewhere in the country
that the same thing happens.

So, nine days in, we're still waiting for someone within "Networks" to try
and connect to this website themselves from their own IP space; they've
still not decided that this issue isn't occurring from the exchange to our

This ISP has 4.2 million residential subscribers, so is fairly sizable.

I'm going to be interested in how long it takes to get to their routing
guys.  It's going to be enlightening to see what happens.


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