An emergency-management office peers city edge routers to two ISPs with eBGP and uses route reflection for iBGP inside the civic ASN. Which behavioral contrast should engineers keep foremost?
Select an answer to reveal the explanation.
Short Explanation
eBGP is the conversation with the outside world—you stamp your ASN and usually hand over a new next hop. iBGP is the hallway chat inside city hall—AS-path stays put, and you still need the IGP to reach whoever originated the route. Reflectors scale that hallway; they don’t turn it into eBGP.
Full Explanation
eBGP updates normally prepend the local AS and set next-hop to self (or the peering address), advertising reachability across AS boundaries. iBGP does not prepend the local AS again and commonly leaves next-hop unchanged, so an IGP must reach the advertising router’s next hop. Route reflectors relax iBGP full-mesh scale without changing those eBGP versus iBGP semantics. Conflating the two peer types leads to next-hop and loop-prevention mistakes.