You have the option to influence the selection of the best path to a destination by means of the following attributes:
- Weight
- Weight is a proprietary attribute, which is not propagated to neighbors by means of BGP update messages. "Weight" is valid on the local router only. You can set the attribute locally either by means of the address family or with filter policies.
- Local preference
- Local preference is a BGP standard attribute (LOCAL_PREF) and is propagated to neighbors via iBGP. All paths have a local preference of 100 by default. This attribute can be used to favor certain prefixes. The attribute can be set by address family or by filter policies.
- AS_PATH
- The AS-Path contains details of the path taken by a route. Filter policies can be used to manipulate the AS path, for example by prepending the device's own AS number multiple times. This makes the AS path appear longer to a neighbor.
- Origin
- Origin is a default BGP attribute, which is propagated to all neighbors. This attribute indicates where a route originated. This could be an Interior Gateway Protocol (IGP), the Exterior Gateway Protocol (EGP, RFC 904), or "Incomplete". Here, "Incomplete" indicates a redistribution by a different routing protocol. The origin attribute is set automatically by the router. The origin of a route is set to IGP if it was added to BGP by means of an entry in the IPv4 / IPv6 network table. The origin for a route is set to "Incomplete" if it was configured for re-distribution in the address families.
- MED
- MED (MULTI_EXIT_DISC) is an optional BGP attribute used to distinguish between multiple inputs or outputs to the same neighbor AS. The attribute can be set by filter policies.
- Router ID
- The router ID, also known as the BGP identifier, is the unique identifier of a router. It consists of the IPv4 address of the router. You can manually configure the router ID under .
