Sharyn, George's recommendation is the technologically easiest to implement. But to ensure the ground is covered, you could use BGP (Border Gateway Protocol). The advantage of using BGP is that you can route ALL of your IP blocks over ALL of your connections to the internet. You are not dependent on your upstream provider's static route of your IP blocks. BGP also eliminates the DNS issue, because when a line goes down, the IP block(s) that are normally statically routed over that line can be routed over your other line(s).
BGP advertises muliple routes to other routers on the internet. Use of BGP requires the cooperation of all of your upstream providers on at least one level. If you implement BGP, your upstream providers (and their upstream providers) must allow you to advertise your IP blocks via their networks. You must also obtain an ASN (Autonomous System Number) from ARIN (FEE: $500 initial and $30 annual). To obtain an ASN, you MUST have two or more routes to the internet. BGP is definitely more challenging technically than George's recommendation. You must also have at least one router (single point of failure, two or more recommended) than can perform BGP. Mike ----- Original Message ----- From: "George Kulman" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Friday, January 10, 2003 9:30 PM Subject: RE: [IMail Forum] OT: DNS/ISP redundency Sharyn, Another solution is to use a Radware LinkProof Lite. Assuming that both your primary and backup circuits are live, you're paying for the backup but not using it all of the time. This solution provides for inbound and outbound load balancing and handles the DNS issues as well by providing DNS on both providers address blocks. You don't need to change any IP addresses on your servers since the unit dynamically NAT's and routes based on the traffic route. Another real benefit is that you're using the backup circuit all of the time instead of having a resource that you're paying for sitting idle. I'm in the process of implementing two of these units in a 'hot-spare' configuration using an SDSL circuit to back up and supplement a T-1. They're really slick. George -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of Sharyn Schmidt Sent: Friday, January 10, 2003 3:40 PM To: [EMAIL PROTECTED] Subject: [IMail Forum] OT: DNS/ISP redundency Good afternoon, Everyone, I would appreciate some suggestions or practices that people out there have implemented regarding DNS and ISP backups. Feel free to email me off list if this thread gets too long and tedious. Right before Christmas, our ISP went out of business without telling anyone. Our whole class C IP address block that we had used for years went off into cyberspace and we were literally left dead in a water. It's an experience that neither myself or my boss ever wants to repeat! Now the that initial crises is over, we are discussing ways to prevent this sort of total outage. Our company is willing to spend the extra bucks and obtain a "backup" internet provider. I host my own primary nameserver here. My question then, is, how is the best way to handle a quick tranfer of DNS? The backup ISP would provide us with several static IP addresses, however, all our DNS points to our current addressing scheme. Is there a way to register a "virtual" primary nameserver (we use Network Solutions) but not have it active? Has anyone else put this sort of backup plan into effect successfully? Just having the backup provider would help, but we would still experience a lot of downtime until the rest of the world knew how to get in touch with us. If anyone has ever used Network Solutions before, you will know that changing an IP address of a primary nameserver when you don't have internet access is worse than undergoing a full background investigation by the FBI. Fri afternoon food for thought. Thanks in advance, and like I said, feel free to email me off list. Sharyn We are the worldwide producer and marketer of the award winning Cruzan Single Barrel Rum, judged "Best in the World" at the annual San Francisco Wine and Spirits Championships. For more information, please click (go to) <html><a href="http://www.cruzanrums.com";>www.cruzanrums.com</a></html> To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/ To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/ To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/
