Depending on their business, using dynamic DNS providers could be a really bad idea. If they deal only with home users who won't even know, it'll probably work. If their customers are security-aware businesses, they probably block all sites hosted with dynamic DNS systems.
Ray > Subject: Re: ISP inbound failover without BGP > From: matt...@corp.crocker.com > Date: Mon, 3 Mar 2014 20:50:26 -0500 > To: elo...@yahoo.com > CC: nanog@nanog.org > > > > Depends on the application, > > SIP, VPN, SMTP, etc just setup both IPs and let the end-user application > figure it out (SIP-UA register to both IPs for example) > > HTTP/HTTPS setup a proxy server in a colo that is multi-homed to frontend the > requests. Then it can load balance traffic over both IPs. > > DNS TTL ‘tricks’ are just that, they work ‘kinda’ > > Fatpipe? Crazy expensive IMHO but I hear they work ok. > > -Matt > > -- > Matthew S. Crocker > President > Crocker Communications, Inc. > PO BOX 710 > Greenfield, MA 01302-0710 > > E: matt...@crocker.com > P: (413) 746-2760 > F: (413) 746-3704 > W: http://www.crocker.com > > > > On Mar 3, 2014, at 8:11 PM, Eric A Louie <elo...@yahoo.com> wrote: > > > 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. > > > >
