As Rob eluded to in order to fully deal with BGP you have to be able to hold the BGP routing table in the device. <meta http-equiv="content-type" content="text/html; charset=utf-8"><a href="http://en.wikipedia.org/wiki/Border_Gateway_Protocol">http://en.wikipedia.org/wiki/Border_Gateway_Protocol</a> has some more info on BGP though.<div>
<br></div><div>You also need to have your own AS number which you have to pay for as well as two ISP's that you can peer with...typically not a free service. But Comcast Business does support this last time I checked.<div>
<br></div><div>Have a look at the TZO HA services. It's as Rob described a DNS service with low ttl that monitors the end points and redirects traffic should one of the links go down. <a href="http://www.autofailover.com/">http://www.autofailover.com/</a> for more information and they do have a SLA with their service.<br>
<div>--</div><div>David</div><div> <br><br><div class="gmail_quote">On Wed, Jul 14, 2010 at 1:22 PM, Rob Taylor <span dir="ltr"><<a href="mailto:rgt@wi.mit.edu">rgt@wi.mit.edu</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
Hi Doc. BGP is Border Gateway Protocol. It is the core routing protocol<br>
on the Internet. It allows you to advertise your network to your<br>
upstream providers, provides redundancy for you network, and allow you<br>
to make intelligent routing decisions about your outbound traffic.<br>
<br>
Depending on how it is implemented, it can require some beefy hardware<br>
to run on to process the large routing tables that the internet is<br>
comprised of. In your case, you might be able to do it with less, if you<br>
only really want it to advertise your networks via multiple paths. You<br>
could probably use a floating static route to make all your outbound<br>
traffic take one link unless that link was down, and then fail over to<br>
the other one.<br>
<br>
I'm not an ISP guy, so someone else out there could probably give you<br>
more insight on using BGP. It's not trivial to setup though.<br>
<br>
I would guess an issue with dual wan routers is the different IP<br>
address's that both external interfaces would have. If you use NAT, then<br>
outbound traffic shouldn't be much of an issue, as it could just get<br>
NAT'ed to the other link(sessions going at the time of the cutover will<br>
break when that happens), but inbound might be.<br>
<br>
I would guess that you could have off-site dns with a low ttl, and have<br>
it give one of IP's of either wan interface, and when one fails, update<br>
it to use the other interface.<br>
<br>
Anyone have any other ideas on how to do it?<br>
<br>
rgt<br>
<div><div></div><div class="h5"><br>
<br>
On 07/14/2010 12:46 PM, Richard 'Doc' Kinne wrote:<br>
> Folks:<br>
><br>
> I wanted to respond with thanks regarding the responses I got for my<br>
> requests for "telecommunications recommendations."<br>
><br>
> I'll say that FIOS is not an option here in West Cambridge. I think my<br>
> Director would die and go to heaven if I could get him FIOS, but not<br>
> in this lifetime apparently.<br>
><br>
> You folks basically were able to clue me in that the difference<br>
> between the DS1 and Comcast was the SLA. That was valuable. Comcast<br>
> business service didn't even know what an SLA was, interestingly<br>
> enough.<br>
><br>
> Daniel's thought on having two input streams coming into the building<br>
> and managing them via a "twin" or "dual" WAN router was very<br>
> interesting. I'm looking at such WAN routers now.<br>
><br>
> Both Daniel and K.M. Peterson spoke of "BGPs" in terms of advertising<br>
> routes. I have to say that I've not encountered the term "BGP" before<br>
> along that line. What is it?<br>
><br>
> Finally, David, your post regarding availability (loved the numbers!)<br>
> and potential port blocking was an important point.<br>
><br>
> At this point it looks like I can get and keep my current service, but<br>
> get it discounted by about 20%. This savings will enable me to add the<br>
> Comcast pipeline all for less than what we pay now. This will enable<br>
> us to have what we want and safely test the reliability of Comcast<br>
> over the long term.<br>
><br>
> Thanks again, folks! The BBLISA list has, and continues to be, a<br>
> critical resource which is invaluable to me, and I'm sure to many<br>
> others as well!<br>
> ----<br>
> Doc Kinne<br>
> AAVSO<br>
> (From the Gmail Web Interface)<br>
><br>
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