BGP question

[Nathan Cruz]

What is the norm when connecting to an ISP. I understand that if you only have one ISP you would just normally use a static default route. So does this mean that you would just fall into your ISPs assigned AS number and that to get to you, the outside would just route to your ISP which would send them to you?   And second what if you did have two ISPs for redundancy (let's say for a critical web server) would you then have to have you're own Internic assigned AS number so you could run BGP to "advertise" to the Internet that you have more than one route to your web server.   Also don't most smaller companies use IP addresses assigned by the ISP so wouldn't the ISP be using route summarization to advertise to the internet. So back to the previous case with the critical web server would you have to have an IP addressed assigned from each ISP and if so how would this work with DNS.   Thanks in advanced for the enlightenment.