Renegotiation not working

According to RFC 5492:

A BGP speaker determines that its peer doesn't support capabilities

advertisement if, in response to an OPEN message that carries the

Capabilities Optional Parameter, the speaker receives a NOTIFICATION

message with the Error Subcode set to Unsupported Optional Parameter.

(This is a consequence of the base BGP-4 specification [RFC4271] and

not a new requirement.) In this case, the speaker SHOULD attempt to

re-establish a BGP connection with the peer without sending to the

peer the Capabilities Optional Parameter.