I'm not sure about the 1605. I've never even seen one. HSRP is one solution. You could point all of your browsers, etc. to the standby ip address.
Another solution might be to run BGP on your external routers. Advertise only your local addresses and accept default-routes-only from both providers. Then, run OSPF on both routers and configure them with default-information originate. Connect both of those routers to a third internal router that is running OSPF only and make that your default gateway, making sure to use some form of CEF or fast switching. You would NOT want to use per-packet load-balancing in a situation like this. This will utilize both links while still responding dynamically to network changes. You have several options, but I'd caution you to move very slowly and make sure you know what you're doing. It might be useful for you to get some outside help on this. When you start playing with BGP in the real world it's very easy to make a lot of people angry with you very quickly. :-) There are both technical and non-technical issues that you need to be aware of before you dive into this particular pool. Trust me, I learned of lot of this the hard way! John >>> "Shawn Xu" 1/16/02 8:24:44 AM >>> Hi, John and Eric: Thank you both for your help. I don't have BGP experience, and I will check the book Eric recommended. We have T1 connection to an ISP using Cisco router 2503 with 207.x.x.x/24 ip addresses, now we also want to connect to another ISP (SDSL line) for load balancing and fault tolerance using Cisco 1605 with 66.x.x.x/29 IPs (or I have more). My questions: 1. As John said, we have to apply for our own AS number? 2. Cisco router 1605 can do BGP? 3. What ip is local clients' default gateway? because for 2503 ip is 207.x.x.x, and for 1605 ip is 66.x.x.x or 1605 connecting to local network interface must use 207.x.x.x ip, even though what is default gateway without HSRP for automatically switching over in any case one line is down? Also we have web server and mail server on our network, how to configure DNS to point to right path? Thanks, please help. Shawn >From: "Eric" >Reply-To: "Eric" >To: [EMAIL PROTECTED] >Subject: Re: BGP AS Number [7:32107] >Date: Wed, 16 Jan 2002 00:36:26 -0500 > >IMHO - You will need at least a /21 as some ISP's set policies that will >filter anything less. > >Best bet is to pick up a copy of: Internet Routing Architectures, Second >Edition. ISBN# 1-57870-233-X. > >This book will also introduce you to the third item to consider when >connecting to two ISP's: Symmetry. > >Regards, >Eric > >----- Original Message ----- >From: "John Neiberger" >To: >Sent: Tuesday, January 15, 2002 7:37 PM >Subject: Re: BGP AS Number [7:32107] > > > > To make connections to separate ISPs work, you need to have > > some address space assigned to you that is large enough to be > > routed successfully. This generally means that you have to > > have at least a /24 prefix. > > > > Once you've successfully gotten that address space from one of > > your providers you can apply at www.arin.net to get an ASN. > > > > If you were only considering multiple connections to the same > > ISP one option would be to use a private ASN, or you might not > > need to use BGP at all. > > > > However, to do what you're considering, you need to have your > > own ASN and address space. > > > > Also, for the nitpickers I'm being overly general on > > purpose. This can get to be much more complicated if you want > > it to be. :-) > > > > HTH, > > John > > > > > > ________________________________________________ > > Get your own "800" number > > Voicemail, fax, email, and a lot more > > http://www.ureach.com/reg/tag > > > > > > ---- On Tue, 15 Jan 2002, Shawn Xu ([EMAIL PROTECTED]) > > wrote: > > > > > As far as we know, when you connect to two ISPs for load > > balancing and > > > fault > > > tolerance, you have to configure BGP, please refer > > > > > > http://www.cisco.com/warp/public/459/40.html > > > > > > but from the above examples, you have to have your own AS > > number. If I > > > don't > > > have my own AS number, I can not connect to two ISPs? > > > > > > Please help, thanks. > > > > > > Shawn Xu > > > > > > > > ________________________________________________________________ > > _ > > > MSN Photos is the easiest way to share and print your photos: > > > http://photos.msn.com/support/worldwide.aspx > > [EMAIL PROTECTED] _________________________________________________________________ Chat with friends online, try MSN Messenger: http://messenger.msn.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=32172&t=32164 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
