Re: BGP for 2 T1's to one LAN [7:7511]
Redundancy and loadbalancing are possible. The hardware is insufficient, though. Redundcy and Load balancing requirements. -- 2 ISPs 2 /24 ASN Two routers capable of 256 Mb of DRAM (3600 and higher) web servers with two IPs, from each block DNS round robin Redundancy only -- 2 ISPs 1 /24 ASN Two routers capable of 256 Mb of DRAM (3600 and higher) -- Sergei GDaniel Wilson wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... We are trying to have the web servers in our LAN accessible to the internet via 2 T1's from different providers -- more for redundancy than load sharing, though that matters too. Currently we have 2 T1's, each giving us a different set of IP addresses. That just lets us put some sites on each T1 -- doesn't give us an ounce of redundancy. I've been told that if we get a router with 2 WIC's that can speak BGP (Cisco 2600 or better) that may solve our problem. I'm very new to routing, so can someone answer some basic questions? Is the idea with this solution that we will be running just one set of IP addresses? And that, because of BGP on our router, either ISP will be able to route traffic to that set of IPs on the T1 it provides? Thanks in advance. -- Daniel Wilson, BSCS, MCP Application Developer http://www.compusoftsolutions.com/ Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=7689t=7511 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: BGP for 2 T1's to one LAN [7:7511]
Thanks. Someone else also mentioned the need for 2 routers for full redundancy. What I'm not understanding is why we need to IP blocks to achieve loadbalancing. That we'd need DNS round robin if we're running 2 blocks makes sense, but why the 2 blocks? Also, are both your lists assuming that the ISPs run BGP with us? Thanks for the help. -- Daniel Wilson, BSCS, MCP Application Developer http://www.compusoftsolutions.com/ Sergei G. wrote: Redundancy and loadbalancing are possible. The hardware is insufficient, though. Redundcy and Load balancing requirements. -- 2 ISPs 2 /24 ASN Two routers capable of 256 Mb of DRAM (3600 and higher) web servers with two IPs, from each block DNS round robin Redundancy only -- 2 ISPs 1 /24 ASN Two routers capable of 256 Mb of DRAM (3600 and higher) -- Sergei GDaniel Wilson wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... We are trying to have the web servers in our LAN accessible to the internet via 2 T1's from different providers -- more for redundancy than load sharing, though that matters too. Currently we have 2 T1's, each giving us a different set of IP addresses. That just lets us put some sites on each T1 -- doesn't give us an ounce of redundancy. I've been told that if we get a router with 2 WIC's that can speak BGP (Cisco 2600 or better) that may solve our problem. I'm very new to routing, so can someone answer some basic questions? Is the idea with this solution that we will be running just one set of IP addresses? And that, because of BGP on our router, either ISP will be able to route traffic to that set of IPs on the T1 it provides? Thanks in advance. -- Daniel Wilson, BSCS, MCP Application Developer http://www.compusoftsolutions.com/ Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=7706t=7511 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: BGP for 2 T1's to one LAN [7:7511]
My opinion would be that best case calls for you to use your own netblock. Get 2 /24's and since you are running with 2 ISPs (multi-homed) you need your own AS. Using 2 routers on your prem and BGP with the ISPs affords you a lot of flexibility. If you only have 1 /24 then its pretty much up to the how the Internet sees your routes as far as which one will be used to get to your site. With 2 /24's you can really start achieving load-sharing (not necessarily load-balancing) Talk with the ISPs and find out what policies they will allow you to pass to them. You could route some traffic via one provider and the rest through the other provider. If they accept manipulated routes (such as AS PATH PREPEND) you could then allow each ISP to back the other one up, and they don't really need to know or care. Advertise your whole network to both, but adjusting the routes so that half takes one ISP while the other half takes the other ISP. Then, upon failure of one ISP, the other would then be advertising the best/only route for your traffic. This takes a little time to consider and hopefully knowledgeable ISP installation techs. This also takes some consideration on your part in respect to your host numbering and usage. HTH Christopher A. Kane, CCNP/CCDA Router Ops Center/Hilliard NOC UUNET/WCOM -Original Message- From: Daniel Wilson [mailto:[EMAIL PROTECTED]] Sent: Friday, June 08, 2001 7:43 AM To: [EMAIL PROTECTED] Subject: Re: BGP for 2 T1's to one LAN [7:7511] Thanks. Someone else also mentioned the need for 2 routers for full redundancy. What I'm not understanding is why we need to IP blocks to achieve loadbalancing. That we'd need DNS round robin if we're running 2 blocks makes sense, but why the 2 blocks? Also, are both your lists assuming that the ISPs run BGP with us? Thanks for the help. -- Daniel Wilson, BSCS, MCP Application Developer http://www.compusoftsolutions.com/ Sergei G. wrote: Redundancy and loadbalancing are possible. The hardware is insufficient, though. Redundcy and Load balancing requirements. -- 2 ISPs 2 /24 ASN Two routers capable of 256 Mb of DRAM (3600 and higher) web servers with two IPs, from each block DNS round robin Redundancy only -- 2 ISPs 1 /24 ASN Two routers capable of 256 Mb of DRAM (3600 and higher) -- Sergei GDaniel Wilson wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... We are trying to have the web servers in our LAN accessible to the internet via 2 T1's from different providers -- more for redundancy than load sharing, though that matters too. Currently we have 2 T1's, each giving us a different set of IP addresses. That just lets us put some sites on each T1 -- doesn't give us an ounce of redundancy. I've been told that if we get a router with 2 WIC's that can speak BGP (Cisco 2600 or better) that may solve our problem. I'm very new to routing, so can someone answer some basic questions? Is the idea with this solution that we will be running just one set of IP addresses? And that, because of BGP on our router, either ISP will be able to route traffic to that set of IPs on the T1 it provides? Thanks in advance. -- Daniel Wilson, BSCS, MCP Application Developer http://www.compusoftsolutions.com/ Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=7713t=7511 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: BGP for 2 T1's to one LAN [7:7511]
Hi! You receive one full BGP table with about 90-1 prefixes from each of the uplink ISPs... 2 ISP, 2 full BGP table... 128MB RAM is enough... -- cU, Laszlo Csosza Sergei G. wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... Redundancy and loadbalancing are possible. The hardware is insufficient, though. Redundcy and Load balancing requirements. -- 2 ISPs 2 /24 ASN Two routers capable of 256 Mb of DRAM (3600 and higher) web servers with two IPs, from each block DNS round robin Redundancy only -- 2 ISPs 1 /24 ASN Two routers capable of 256 Mb of DRAM (3600 and higher) -- Sergei GDaniel Wilson wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... We are trying to have the web servers in our LAN accessible to the internet via 2 T1's from different providers -- more for redundancy than load sharing, though that matters too. Currently we have 2 T1's, each giving us a different set of IP addresses. That just lets us put some sites on each T1 -- doesn't give us an ounce of redundancy. I've been told that if we get a router with 2 WIC's that can speak BGP (Cisco 2600 or better) that may solve our problem. I'm very new to routing, so can someone answer some basic questions? Is the idea with this solution that we will be running just one set of IP addresses? And that, because of BGP on our router, either ISP will be able to route traffic to that set of IPs on the T1 it provides? Thanks in advance. -- Daniel Wilson, BSCS, MCP Application Developer http://www.compusoftsolutions.com/ Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=7769t=7511 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: BGP for 2 T1's to one LAN [7:7511]
1 /24 from each provider and round robin dns is not necessary if you get both providers to route 1 /24. So ithe /24 belongs tp provider a, just talk provider b into routing it. If you're doing bgp with them, this is a perfectly reasonable request. Brian Sonic Whalen Success = Preparation + Opportunity On Fri, 8 Jun 2001, Sergei G. wrote: Redundancy and loadbalancing are possible. The hardware is insufficient, though. Redundcy and Load balancing requirements. -- 2 ISPs 2 /24 ASN Two routers capable of 256 Mb of DRAM (3600 and higher) web servers with two IPs, from each block DNS round robin Redundancy only -- 2 ISPs 1 /24 ASN Two routers capable of 256 Mb of DRAM (3600 and higher) -- Sergei GDaniel Wilson wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... We are trying to have the web servers in our LAN accessible to the internet via 2 T1's from different providers -- more for redundancy than load sharing, though that matters too. Currently we have 2 T1's, each giving us a different set of IP addresses. That just lets us put some sites on each T1 -- doesn't give us an ounce of redundancy. I've been told that if we get a router with 2 WIC's that can speak BGP (Cisco 2600 or better) that may solve our problem. I'm very new to routing, so can someone answer some basic questions? Is the idea with this solution that we will be running just one set of IP addresses? And that, because of BGP on our router, either ISP will be able to route traffic to that set of IPs on the T1 it provides? Thanks in advance. -- Daniel Wilson, BSCS, MCP Application Developer http://www.compusoftsolutions.com/ Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=7796t=7511 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
BGP for 2 T1's to one LAN [7:7511]
We are trying to have the web servers in our LAN accessible to the internet via 2 T1's from different providers -- more for redundancy than load sharing, though that matters too. Currently we have 2 T1's, each giving us a different set of IP addresses. That just lets us put some sites on each T1 -- doesn't give us an ounce of redundancy. I've been told that if we get a router with 2 WIC's that can speak BGP (Cisco 2600 or better) that may solve our problem. I'm very new to routing, so can someone answer some basic questions? Is the idea with this solution that we will be running just one set of IP addresses? And that, because of BGP on our router, either ISP will be able to route traffic to that set of IPs on the T1 it provides? Thanks in advance. -- Daniel Wilson, BSCS, MCP Application Developer http://www.compusoftsolutions.com/ Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=7511t=7511 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: BGP for 2 T1's to one LAN [7:7511]
hi! go to cco and do search on bgp multihoming. you will see there are some pretty good documents on it. Dragi Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=7513t=7511 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: BGP for 2 T1's to one LAN [7:7511]
Daniel Wilson wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... We are trying to have the web servers in our LAN accessible to the internet via 2 T1's from different providers -- more for redundancy than load sharing, though that matters too. Currently we have 2 T1's, each giving us a different set of IP addresses. That just lets us put some sites on each T1 -- doesn't give us an ounce of redundancy. I've been told that if we get a router with 2 WIC's that can speak BGP (Cisco 2600 or better) that may solve our problem. I'm very new to routing, so can someone answer some basic questions? Is the idea with this solution that we will be running just one set of IP addresses? And that, because of BGP on our router, either ISP will be able to route traffic to that set of IPs on the T1 it provides? Thanks in advance. -- Daniel Wilson, BSCS, MCP Application Developer http://www.compusoftsolutions.com/ Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=7516t=7511 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: BGP for 2 T1's to one LAN [7:7511]
The quick responses on this group are great! Thanks for the help so far. The content is not static. The sites in question run e-commerce. We could look at setting up access from both servers to the same DB server over an internal network ... so that would answer that objection to the solution you offered. I started by asking questions on a different group about round-robin DNS. What I was told was that since we don't control anyone else's DNS caching settings (our TTL entries etc. are really only suggestions) that when one T1 goes down we change the DNS settings to point to only the other line clients other DNS servers would still try to access the downed T1. Is this accurate as far as you know? If round robin DNS will provide fault-tolerance, that's great. If not ... we need to look elsewhere. Thanks! -- Daniel Wilson, BSCS, MCP Application Developer http://www.compusoftsolutions.com/ Vijay Ramcharan wrote: I believe what you're looking for is a way to load balance traffic to your web servers. You also wish to achieve a degree of fault tolerance in case one server goes down. If both servers have the same content and the content is static, you could use a feature called DNS round-robin which basically returns a list of IP addresses to a querying client for any single hostname. If one server becomes unavailable the client can use the other IP addresses given by the DNS server to access the same site. There's no routing protocol involved here and I don't think it's possible to do what you need using a routing protocol. The good thing about DNS round-robin is that the IP addresses of the web servers could be totally unrelated. This seems to be more of an application specific need for fault tolerance. If this is possible using a routing protocol I'd be happy if someone pointed out the error of my ways. I'm always open to suggestions. Vijay Ramcharan -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of Daniel Wilson Sent: Thursday, June 07, 2001 9:39 AM To: [EMAIL PROTECTED] Subject: BGP for 2 T1's to one LAN [7:7511] We are trying to have the web servers in our LAN accessible to the internet via 2 T1's from different providers -- more for redundancy than load sharing, though that matters too. Currently we have 2 T1's, each giving us a different set of IP addresses. That just lets us put some sites on each T1 -- doesn't give us an ounce of redundancy. I've been told that if we get a router with 2 WIC's that can speak BGP (Cisco 2600 or better) that may solve our problem. I'm very new to routing, so can someone answer some basic questions? Is the idea with this solution that we will be running just one set of IP addresses? And that, because of BGP on our router, either ISP will be able to route traffic to that set of IPs on the T1 it provides? Thanks in advance. -- Daniel Wilson, BSCS, MCP Application Developer http://www.compusoftsolutions.com/ Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=7527t=7511 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: BGP for 2 T1's to one LAN [7:7511]
I'll take a stab at some of this ... First - If I recall, and I may very well be wrong here, I though DNS round-robin was solely for load-sharing, not redundancy. Second - Regarding BGP multi-homing ... some gotchya's that we ran into: You will need an ASN Some ISP's have netblocks designated as re-routable, if your netblock isn't one of them they will make you re-address . Some ISP's require a /24 netblock to be used for BGP routing Some ISP's require that you also register your maintainer object with RADB Routers must have 64mb RAM for partial/default routes and be BGP capable Also, since you are doing this for fault-tolerance reasons, I would also recommend using: two separate routers ... each with 1 WIC and 2 FastEthernet interfaces the WIC -- ISP Fast 0/0 -- your LAN , running HSRP Fast 0/1 -- other router ... this will be for iBGP And you could then multi-home each of your servers to each of the switches and use NIC teaming for redundancy there In this case - all of your outbound traffic will use the ISP connected to the router with the active HSRP address, while all inbound traffic will come in via the ISP with the lowest BGP 'cost' from the source ... not balancing, but load sharing . I am probably forgetting something here, but the idea is to have no single point of failure :) Thanks! TJ -Original Message- We are trying to have the web servers in our LAN accessible to the internet via 2 T1's from different providers -- more for redundancy than load sharing, though that matters too. Currently we have 2 T1's, each giving us a different set of IP addresses. That just lets us put some sites on each T1 -- doesn't give us an ounce of redundancy. I've been told that if we get a router with 2 WIC's that can speak BGP (Cisco 2600 or better) that may solve our problem. I'm very new to routing, so can someone answer some basic questions? Thanks in advance. -- Daniel Wilson, BSCS, MCP Application Developer http://www.compusoftsolutions.com/ * The information in this email is confidential and may be legally privileged. It is intended solely for the addressee. Access to this email by anyone else is unauthorized. If you are not the intended recipient, any disclosure, copying, distribution or any action taken or omitted to be taken in reliance on it, is prohibited and may be unlawful. When addressed to our clients any opinions or advice contained in this email are subject to the terms and conditions expressed in the governing KPMG client engagement letter. * Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=7528t=7511 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: BGP for 2 T1's to one LAN [7:7511]
Since you're running an e-commerce site then users probably establish sessions which are dynamic in nature, passwords, logins etc. If you need failover capabilities you need to consider that if a failover did occur, you'd want active, open sessions statefully failed over to the backup server. I'd be pretty pissed if I was in the midst of a high dollar transaction and my session died on me. Things could get pretty complicated there. The only way I know of achieving that sort of capability is by doing clustering. Since your application is already installed and running, then a cluster solution is more difficult to engineer. Anyway this is way out of my league. I respectfully bow my way out of this thread to make way for someone more versed in this arena. :-) Vijay Ramcharan -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of Daniel Wilson Sent: Thursday, June 07, 2001 10:42 AM To: [EMAIL PROTECTED] Subject: Re: BGP for 2 T1's to one LAN [7:7511] The quick responses on this group are great! Thanks for the help so far. The content is not static. The sites in question run e-commerce. We could look at setting up access from both servers to the same DB server over an internal network ... so that would answer that objection to the solution you offered. I started by asking questions on a different group about round-robin DNS. What I was told was that since we don't control anyone else's DNS caching settings (our TTL entries etc. are really only suggestions) that when one T1 goes down we change the DNS settings to point to only the other line clients other DNS servers would still try to access the downed T1. Is this accurate as far as you know? If round robin DNS will provide fault-tolerance, that's great. If not ... we need to look elsewhere. Thanks! -- Daniel Wilson, BSCS, MCP Application Developer http://www.compusoftsolutions.com/ Vijay Ramcharan wrote: I believe what you're looking for is a way to load balance traffic to your web servers. You also wish to achieve a degree of fault tolerance in case one server goes down. If both servers have the same content and the content is static, you could use a feature called DNS round-robin which basically returns a list of IP addresses to a querying client for any single hostname. If one server becomes unavailable the client can use the other IP addresses given by the DNS server to access the same site. There's no routing protocol involved here and I don't think it's possible to do what you need using a routing protocol. The good thing about DNS round-robin is that the IP addresses of the web servers could be totally unrelated. This seems to be more of an application specific need for fault tolerance. If this is possible using a routing protocol I'd be happy if someone pointed out the error of my ways. I'm always open to suggestions. Vijay Ramcharan -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of Daniel Wilson Sent: Thursday, June 07, 2001 9:39 AM To: [EMAIL PROTECTED] Subject: BGP for 2 T1's to one LAN [7:7511] We are trying to have the web servers in our LAN accessible to the internet via 2 T1's from different providers -- more for redundancy than load sharing, though that matters too. Currently we have 2 T1's, each giving us a different set of IP addresses. That just lets us put some sites on each T1 -- doesn't give us an ounce of redundancy. I've been told that if we get a router with 2 WIC's that can speak BGP (Cisco 2600 or better) that may solve our problem. I'm very new to routing, so can someone answer some basic questions? Is the idea with this solution that we will be running just one set of IP addresses? And that, because of BGP on our router, either ISP will be able to route traffic to that set of IPs on the T1 it provides? Thanks in advance. -- Daniel Wilson, BSCS, MCP Application Developer http://www.compusoftsolutions.com/ Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=7532t=7511 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: BGP for 2 T1's to one LAN [7:7511]
The answer is: It depends. :) When you make use of round robin DNS your clients do recieve multiple records. This is from a single hit to www.microsoft.com and shows the dns cache on the local machine. www.microsoft.com. -- Record Name . . . . . : www.microsoft.com Record Type . . . . . : 5 Time To Live . . . . : 7124 Data Length . . . . . : 4 Section . . . . . . . : Answer CNAME Record . . . . : www.microsoft.akadns.net Record Name . . . . . : www.microsoft.akadns.net Record Type . . . . . : 1 Time To Live . . . . : 7124 Data Length . . . . . : 4 Section . . . . . . . : Answer A (Host) Record . . . : 207.46.131.91 Record Name . . . . . : www.microsoft.akadns.net Record Type . . . . . : 1 Time To Live . . . . : 7124 Data Length . . . . . : 4 Section . . . . . . . : Answer A (Host) Record . . . : 207.46.230.229 Record Name . . . . . : www.microsoft.akadns.net Record Type . . . . . : 1 Time To Live . . . . : 7124 Data Length . . . . . : 4 Section . . . . . . . : Answer A (Host) Record . . . : 207.46.230.218 Now, just because the host recieves this information, doesn't mean that the host will USE all this information. YMMV, VWPBL, TOSTCAAT. And this only addresses redundancy near the top of the OSI model. You are also looking to make redundancy happen at the bottom, and that's why you have two T-1s, and you've gotten some good answers on that. And if it's so bloody important, you probably will be wanting to put in some redundancy at the server as well, perhaps Win2K Network Load Balancing or something from the *nix world. And remember, always ask 'What happens if Mars explodes?' TTFN, Bill in Anchorage -Original Message- If the ISP dies then, yes you'll lose both sites, but the world is a single point of failure. I believe the problem with the DNS solution is that although a DNS TTL can be set to 0, there is only a requirement to support TTL down to 2 days. So DNS info can be cached for this period by non-authorative DNS'. Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=7540t=7511 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: BGP for 2 T1's to one LAN [7:7511]
If the ISP dies then, yes you'll lose both sites, but the world is a single point of failure. Unfortunately, all the ISP's we've worked with are much more likely to fail than the world is or the Internet at large is. Both ISP's we have now (names withheld to protect the guilty) have bad habits of messing up their routing tables and cutting us off. We will do a trace from the outside and find to routers looking at each other. Makes for comical traceroutes, but doesn't keep e-commerce running. With one ISP we have to wade through support personel who think that bringing us cell phones will be a temporary solution before we finally (maybe) talk to someone who knows a router from a microwave oven. The other ISP will tell us we can't telnet to your router. Go power-cycle it call back. Or they'll say, we are connected to your router. Are you sure there's a problem? So we are trying hard to get out of being dependent on any one provider. Thank you all for all the help -- Daniel Wilson, BSCS, MCP Application Developer http://www.compusoftsolutions.com/ Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=7551t=7511 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: BGP for 2 T1's to one LAN [7:7511]
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 I am in the same position as you, we are just about to get an additional T1, and then move the current and new T1 into a 3640. The ISP that is managing it for us says that BGP will do the job. I don't know much at all about BGP (although am studying now) but I think it will work. I am uncertain as to the best way to do it however. I also looked at DNS round robin, and it will work, but it is a lot uglier than using one address range and BGP. If you use DNS RR, then when a client does a lookup, it will recieve all A records, and will try one then the other, so there isn't that much of an issue. I don't think it is robust enough for e-commerce sites that demand high availability though, which is why we are going to BGP. I will keep you updated as we go through the implementation. Symon - -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Daniel Wilson Sent: 07 June 2001 15:42 To: [EMAIL PROTECTED] Subject: Re: BGP for 2 T1's to one LAN [7:7511] The quick responses on this group are great! Thanks for the help so far. The content is not static. The sites in question run e-commerce. We could look at setting up access from both servers to the same DB server over an internal network ... so that would answer that objection to the solution you offered. I started by asking questions on a different group about round-robin DNS. What I was told was that since we don't control anyone else's DNS caching settings (our TTL entries etc. are really only suggestions) that when one T1 goes down we change the DNS settings to point to only the other line clients other DNS servers would still try to access the downed T1. Is this accurate as far as you know? If round robin DNS will provide fault-tolerance, that's great. If not ... we need to look elsewhere. Thanks! - -- Daniel Wilson, BSCS, MCP Application Developer http://www.compusoftsolutions.com/ Vijay Ramcharan wrote: I believe what you're looking for is a way to load balance traffic to your web servers. You also wish to achieve a degree of fault tolerance in case one server goes down. If both servers have the same content and the content is static, you could use a feature called DNS round-robin which basically returns a list of IP addresses to a querying client for any single hostname. If one server becomes unavailable the client can use the other IP addresses given by the DNS server to access the same site. There's no routing protocol involved here and I don't think it's possible to do what you need using a routing protocol. The good thing about DNS round-robin is that the IP addresses of the web servers could be totally unrelated. This seems to be more of an application specific need for fault tolerance. If this is possible using a routing protocol I'd be happy if someone pointed out the error of my ways. I'm always open to suggestions. Vijay Ramcharan -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of Daniel Wilson Sent: Thursday, June 07, 2001 9:39 AM To: [EMAIL PROTECTED] Subject: BGP for 2 T1's to one LAN [7:7511] We are trying to have the web servers in our LAN accessible to the internet via 2 T1's from different providers -- more for redundancy than load sharing, though that matters too. Currently we have 2 T1's, each giving us a different set of IP addresses. That just lets us put some sites on each T1 -- doesn't give us an ounce of redundancy. I've been told that if we get a router with 2 WIC's that can speak BGP (Cisco 2600 or better) that may solve our problem. I'm very new to routing, so can someone answer some basic questions? Is the idea with this solution that we will be running just one set of IP addresses? And that, because of BGP on our router, either ISP will be able to route traffic to that set of IPs on the T1 it provides? Thanks in advance. -- Daniel Wilson, BSCS, MCP Application Developer http://www.compusoftsolutions.com/ [EMAIL PROTECTED] -BEGIN PGP SIGNATURE- Version: PGPfreeware 7.0.3 for non-commercial use iQA/AwUBOx/pXySR4L/PyJNuEQIzlwCgn526u+eQfDo1NKjl5toGM4YgIloAniHF rBd86dwq0wiGRUGAgXjeBQwW =j5yI -END PGP SIGNATURE- Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=7633t=7511 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
