01-09-2017 08:04 AM
We are a small telco/ISP. We have a Borcade MLXe8 switch setup currently with eBGP from 2 different upstream providers. Provider A is a 90 meg circuit and Provider B is a 250 meg circuit. We will soon be adding a 1 gig circuit to the mix as well. I am seeking advice on how we may want or need to setup up our 3rd provider. What would be our best bet for our end customers so that they will not see any issues with their internet service? It is my understanding that load balancing can be difficult when the updtream providers are different carriers.
01-10-2017 03:36 AM
When you add the 3rd provider, the routes will be installed by the regular BGP selection process which can be seen under
The questions that need to be answered:
- What is my current configuration? Do I use local-preferences, weight? Is the second line "backup" only-configured?
- How is my upstream billed and what commitment do I need to run monthly?
- What are the regular target networks (write down AS!) and could some targets be congested at peak-time on my upstream carrier?
When you are ready to activate the third carrier, my steps would be:
- configure 'auto-shutdown-new-neighbors' under router/bgp
- configure the bgp neighbor
- add route-map to deny any outgoing / incoming prefix or add a filter-list
- startup the bgp neighbor (no remote ... shutdown), check if bgp is establised
- outgoing filter / route-map: send some unused prefix or less important prefix to check if the bgp process work, test routing (looking glass, support..)
- incoming filter / route-map: add routes to specific AS for testing purposes, deny others. Or: Add whole routes with low prefercence (local-preference, weigth)
- everything fine? add normal production route-maps, remove the test incoming/outgoing-filters