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]
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