Start networking and exchanging professional insights

Register now or log in to join your professional community.

Follow

Which attribute must exist in the BGP update packet?

A. LOCAL_PREF B. AGGREGATOR C. AS_Path D. Weight

user-image
Question added by mohammed elsayed hesseny mohammed Elaidy , Service Level & Quality Management Engineer , TE-data
Date Posted: 2014/01/15
Fahad Faiz
by Fahad Faiz , Executive II , WorldCall Telecom Limited - An Omantel Company

Assalam-o-Alaikum 

Its AS-Path a.k.a Mandatory well known Attribute, and it also includes Origin and Next HOP (these attritubes should exist in a BGP packet). 

And all the other options are Optional Attributes and they will only exist if you have made some tuning in your BGP network.     

mohammed elsayed hesseny mohammed Elaidy
by mohammed elsayed hesseny mohammed Elaidy , Service Level & Quality Management Engineer , TE-data

also you can check the below :

Explanation:Origin, AS_Path, Next_Hop are well-known mandatory BGP attributes that all BGP Updatesmust include.Note:There are4 BGP attribute types:+ Well-known Mandatory: recognized by all implementations of BGP and mustappear in aBGP update message. If missing, a notification error will be generated.+ Well-Known Discretionary: recognized by all implementations of BGP but may not besent 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 notrecognized (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 isnot passed along to other BGP peers (include MED).

Shahzada Khan
by Shahzada Khan , Network and Security Engineer (Resident/Onsite) , Etisalat UAE

AS path, Origin and Next hop is mandatory attributes which must exists on every BGP updates.

Tarek Mabrouk  Menshawy
by Tarek Mabrouk Menshawy , Network and Security Head , CICAPITAL

C. AS_Path