Re: ISP inbound failover without BGP

[Eric A Louie <elouie () yahoo com>]

That's a good point Ray - thank you.




> ________________________________
> From: Ray <sixsigma44 () hotmail com>
> To: Matthew Crocker <matthew () corp crocker com>; Eric A Louie <elouie () 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: matthew () corp crocker com
> > Date: Mon, 3 Mar 2014 20:50:26 -0500
> > To: elouie () 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: matthew () 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 <elouie () 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.