Honestly? Because the end-customers are not technically competent enough to run dual-homed BGP, and we don't want to be their managed service providers on the IT side. And announcing the AT&T space is fine until something goes wrong, and I have to troubleshoot the problem (Customer - "How come AT&T is down, and we're not getting inbound traffic to our servers?", and I discover L3 or CenturyLink isn't accepting my advertisement for some weird reason, but they won't fess up to it for a few frustrating hours)
>________________________________ > From: Randy Carpenter <rcar...@network1.net> >To: Eric A Louie <elo...@yahoo.com> >Cc: NANOG <nanog@nanog.org> >Sent: Monday, March 3, 2014 7:20 PM >Subject: Re: ISP inbound failover without BGP > > > >Is there some technical reason that BGP is not an option? You could allow them >to announce their AT&T space via you as a secondary. > >-Randy > >----- Original Message ----- >> This may sound like dumb question, but... I'm used to asking those. >> >> Here's the scenario >> >> Another ISP, say AT&T, is the primary ISP for a customer. >> >> Customer has publicly accessible servers in their office, using the AT&T >> address space. >> >> I am the customer's secondary ISP. >> >> Now, if AT&T link fails, I can provide the customer outbound Internet access >> fairly easily. So they can surf and get to the Internet. >> >> What about the publicly accessible servers that have AT&T addresses, though? >> >> One thought I had was having them use Dynamic DNS service. >> >> Are there any other solutions, short of using BGP multihoming and having them >> try to get their own ASN and IPv4 /24 block? >> >> >> It looks like a few router manufacturers have devices that might work, but it >> looks like a short DNS TTL (or Dynamic DNS) needs to be set so when the >> primary ISP fails, the secondary ISP address is advertised. >> >> > > >
