[169553] in North American Network Operators' Group
Re: ISP inbound failover without BGP
daemon@ATHENA.MIT.EDU (Matthew Crocker)
Mon Mar 3 20:50:58 2014
From: Matthew Crocker <matthew@corp.crocker.com>
In-Reply-To: <1393895467.63537.YahooMailNeo@web181605.mail.ne1.yahoo.com>
Date: Mon, 3 Mar 2014 20:50:26 -0500
To: Eric A Louie <elouie@yahoo.com>
Cc: NANOG <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
Depends on the application, =20
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 =91tricks=92 are just that, they work =91kinda=92
Fatpipe? Crazy expensive IMHO but I hear they work ok.
-Matt
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Matthew S. Crocker
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PO BOX 710
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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.
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> Here's the scenario
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> Another ISP, say AT&T, is the primary ISP for a customer.
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> Customer has publicly accessible servers in their office, using the =
AT&T address space.
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> I am the customer's secondary ISP.
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> 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.
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> What about the publicly accessible servers that have AT&T addresses, =
though?
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> One thought I had was having them use Dynamic DNS service. =20
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> Are there any other solutions, short of using BGP multihoming and =
having them try to get their own ASN and IPv4 /24 block?
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> 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.
>=20
