Concept Guide

Since each BGP router talking to another router is a session, a BGP network needs to be in “full mesh.” This is a topology that has every
router directly connected to every other router. Each BGP router within an AS must have iBGP sessions with all other BGP routers in the
AS. For example, a BGP network within an AS needs to be in “full mesh.” As seen in the illustration below, four routers connected in a full
mesh have three peers each, six routers have ve peers each, and eight routers in full mesh have seven peers each.
Figure 18. BGP Routers in Full Mesh
The number of BGP speakers each BGP peer must maintain increases exponentially. Network management quickly becomes impossible.
AS4 Number Representation
Dell EMC Networking OS supports multiple representations of 4-byte AS numbers: asplain, asdot+, and asdot.
NOTE
: The ASDOT and ASDOT+ representations are supported only with the 4-Byte AS numbers feature. If 4-Byte AS numbers
are not implemented, only ASPLAIN representation is supported.
ASPLAIN is the default method the system uses. With the ASPLAIN notation, a 32-bit binary AS number is translated into a decimal value.
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Border Gateway Protocol (BGP)