Which attribute must exist in the BGP update packet?
A.
LOCAL_ PREF
B.
AGGREGATOR
C.
AS_Path
D.
Weight
Explanation:
Origin, AS_Path, Next_Hop are well-known mandatory BGP attributes that all BGP Updates must
include.
Note:
There are 4 BGP attribute types:
+ Well-known Mandatory: recognized by all implementations of BGP and must appear in a BGP
update message. If missing, a notification error will be generated.+ Well-Known Discretionary:
recognized by all implementations of BGP but may not be sent in the BGP update message
(include LOCAL_PREF, ATOMIC_AGGREGATOR).+ Optional Transitive: may or may not be
recognized by all BGP implementations. Because the attribute is transitive, BGP accepts and
advertises the attribute even if it is not recognized (include Community attribte).+ Optional
Nontransitive: may or may not be recognized by all BGP implementations. Whether or not the
receiving BGP router recognizes the attribute, it is nontransitive and is not passed along to other
BGP peers (include MED).