Border Gateway protocol (BGP) is a large-scale routing protocol used to communicate routing information between Autonomous Systems (ASs), which are well-defined, separately administered network domains. BGP support allows for firewalls to replace a traditional BGP router on the edge of a network's AS. The current SonicWALL implementation of BGP is most appropriate for "single-provider / single-homed" environments, where the network uses one ISP as their Internet provider and has a single connection to that provider. SonicWALL BGP is also capable of supporting "single-provider / multi-homed" environments, where the network uses a single ISP but has a small number of separate routes to the provider. BGP is enabled on the Network > Routing page of the SonicOS GUI and then it is fully configured through the SonicOS Command Line Interface (CLI).BGP transmits packets in the clear. Therefore for strong security, SonicWALL recommends configuring an IPSec tunnel to use for BGP sessions. For an example of this configuration, see IPSec Configuration for BGP .