Would you please explain BGP SoO concept

Hi Rene,

Would you please explain BGP SoO concept with lab asap, thanks in advance

Hi Rohit,

I’ll give you a quick example for now and perhaps create a lesson for this later. Take a look at this example:

The CE routers use the same AS number and we use BGP allow AS in so that the CE routers accept prefixes with their own AS number.

Now imagine we have a direct link in between CE1 and CE2. We can have a routing loop here since BGP prefixes could be advertised from CE1 > PE1 > P > PE2 > CE2 > CE1.

To prevent this from happening, we add a SoO (Site of Origin) community tag to prefixes. This allows BGP to check where a prefix originated and prevents it from advertising it from CE2 to CE1 (or vice versa).


Thank you so much for your reply.!!
Could please give me a short notes on these topics as well please :-

explicit null
Implicit null
type of labels

I asked you because your language is very easy to understand and remember so please please give me some notes on that as well.!!

I look forward to hearing from you

Thanks in advance.!