That's a good point Ray - thank you.
>________________________________ > From: Ray <sixsigm...@hotmail.com> >To: Matthew Crocker <matt...@corp.crocker.com>; Eric A Louie ><elo...@yahoo.com> >Cc: NANOG <nanog@nanog.org> >Sent: Monday, March 3, 2014 6:31 PM >Subject: RE: ISP inbound failover without BGP > > > > >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. >> > >> >> > > >
