Google ADs
Administrative Distance (abbreviation for AD) is a value that routers/Layer 3 switches use in order to select the best path when there are more than 1 routes to the same destination from two different routing protocols.Administrative Distance (AD) is a numeric value which can range from 0 to 255 and is referred as standard for route preference across vendors.
Below table gives the default Administrative Distance for all the Routing protocols –
ROUTE TYPE | ADMINISTRATIVEDISTANCE | ROUTING TABLEENTRY |
| Connected | 0 | C |
| Static Route out an interface | 0 | S |
| Static Route to Next-Hop IP | 1 | S |
| EIGRP Summary route | 5 | D |
| External BGP | 20 | B |
| Internal EIGRP | 90 | D |
| IGRP | 100 | I |
| OSPF | 110 | O |
| IS-IS | 115 | i |
| RIP v1 & v2 | 120 | R |
| Exterior Gateway Protocol (EGP) | 140 | E |
| ODR | 160 | O |
| External EIGRP | 170 | D EX |
| Internal BGP | 200 | B |
| Unknown | 255 |
Watch the below given video for better understanding of Administrative distance:
ABOUT THE AUTHOR
Founder of AAR TECHNOSOLUTIONS, Rashmi is an evangelist for IT and technology. With more than 12 years in the IT ecosystem, she has been supporting multi domain functions across IT & consultancy services, in addition to Technical content making.
You can learn more about her on her linkedin profile – Rashmi Bhardwaj
