Check-First-AS

Checks whether the first AS number in the AS path of received Update messages corresponds to the AS number of the neighbor. If this is not the case, this route is discarded.

Note: This check must be disabled if the router is connected with a BGP route server which, although it distributes routes, is not itself in the routing path and/or inserts its own AS into the AS path.
SNMP ID:
2.93.1.1.8 
Telnet path:
Setup > Routing-Protocols > BGP > BGP-Instance
Possible values:
Yes
No
Default:
Yes