ShowIPBGP

Controlling inbound traffic is the most important consideration when you are configuring BGP. If you have more than one ISP links, definetely you need to make sure your BGP announcement is propagate to Internet. If you have only one link to the ISP, again you don't really need BGP. Simple static route statement should be taking care of your needs.
Redundancy, failover and load-balancing traffic those are few major reasons that you have multiple links to ISP. Your BGP announcement is directly affecting your inbound traffic. Yes, it kinds of confuse if you are not dealing with BGP daily basis. How you annouce your routes bring traffic on one of your uplinks.

• BGP Tutorial for ISP customers - Do I need BGP?
• BGP Tutorial for ISP customers - Own ASN or borrowing one.
• BGP Tutorial for ISP customers - Enough memory for full routes?
• BGP Tutorial for ISP customers - Controlling outbound traffic.
• BGP Tutorial for ISP customers - Controlling inbound traffic.
• BGP Tutorial for ISP customers - Configuring BGP.
• BGP Tutorial for ISP customers - BGP community string from ISP.
• BGP Tutorial for ISP customers - Verifying BGP routes.
• BGP Tutorial for ISP customers - BGP Troubleshooting.

Outbound traffic control is actually easier than you thought. If you have single ISP link, all outbound traffic will obviously exit out the link. As I mentioned earlier, if you have single ISP link then you don't really need BGP. Probably you may have more questions, if you have more than two ISP links. Redundanacy and load-sharing would be biggest concerns.

• BGP Tutorial for ISP customers - Do I need BGP?
• BGP Tutorial for ISP customers - Own ASN or borrowing one.
• BGP Tutorial for ISP customers - Enough memory for full routes?
• BGP Tutorial for ISP customers - Controlling outbound traffic.
• BGP Tutorial for ISP customers - Controlling inbound traffic.
• BGP Tutorial for ISP customers - Configuring BGP.
• BGP Tutorial for ISP customers - BGP community string from ISP.
• BGP Tutorial for ISP customers - Verifying BGP routes.
• BGP Tutorial for ISP customers - BGP Troubleshooting.

In the most of cases, end-user wants to have full BGP routing table from their upstream provider. Why not! If you have enough memory on your CPE such as Router, multi-layer switch or whatever devices are connected to ISP with BGP on. Certified memory is really expensive. It is not like PC memory. In here, we are just talking about BGP routing table in IPv4 address basis.

• BGP Tutorial for ISP customers - Do I need BGP?
• BGP Tutorial for ISP customers - Own ASN or borrowing one.
• BGP Tutorial for ISP customers - Enough memory for full routes?
• BGP Tutorial for ISP customers - Controlling outbound traffic.
• BGP Tutorial for ISP customers - Controlling inbound traffic.
• BGP Tutorial for ISP customers - Configuring BGP.
• BGP Tutorial for ISP customers - BGP community string from ISP.
• BGP Tutorial for ISP customers - Verifying BGP routes.
• BGP Tutorial for ISP customers - BGP Troubleshooting.

In order to setup BGP, minimum requirements are IP address and ASN. Of course your router must support BGP routing protocol. What is ASN? It is stands for Autonomous Systems Number that is a unique number associated with an AS. The ASN is used as an identifier to allow the AS to exchange dynamic routing information between ASes.
 

• BGP Tutorial for ISP customers - Do I need BGP?
• BGP Tutorial for ISP customers - Own ASN or borrowing one.
• BGP Tutorial for ISP customers - Enough memory for full routes?
• BGP Tutorial for ISP customers - Controlling outbound traffic.
• BGP Tutorial for ISP customers - Controlling inbound traffic.
• BGP Tutorial for ISP customers - Configuring BGP.
• BGP Tutorial for ISP customers - BGP community string from ISP.
• BGP Tutorial for ISP customers - Verifying BGP routes.
• BGP Tutorial for ISP customers - BGP Troubleshooting.