OER

OER or Optimised Edge Routing. Also known as PFR or Performance Routing is now part of the v4 blueprint. In summary it is a feature that enables selection of a route based on its dynamic performance metrics. Something lacking with traditional routing protocols that assign a metric to a route. This assigned metric is in effect the static expected performance of the route that can be used when comparing with any route alternates.

OER is a step towards route selection based on true dynamic performance e.g. in terms of real round trip times of packets. There’s quite a bit of configuring required. CISCO lays out five phases

• Profiling
• Measuring
• Policy Application
• Control
• Verification

The components of OER include a Master Controller (MC) and the Border Routers (BR). The BR’s send performance statistics to the MC. The MC sends routing policy decisions to the BR’s. It’s the BRs that sit on the edge of the network and implement the policies to control the traffic leaving on the external links.

Here i lay out the basic config between MC and Borders. Authentication via a key chain between MC and BR is not optional.

Master Configuration

R1
key chain RIC
key 1
key-string ROUTERRIC

oer master
keepalive 10
logging
!
border 2.2.2.2 key-chain RIC
interface Serial1/0 external
interface Ethernet0/0 internal
!
border 3.3.3.3 key-chain RIC
interface Serial1/0 external
interface Ethernet0/0 internal



Border Config on R2 and R3

key chain RIC
key 1
key-string ROUTERRIC
!
oer border
local Loopback0
master 1.1.1.1 key-chain RIC

Verification On R1

R1#show oer master
OER state: ENABLED and ACTIVE
Conn Status: SUCCESS, PORT: 3949
Number of Border routers: 2
Number of Exits: 2
Number of monitored prefixes: 0 (max 5000)
Max prefixes: total 5000 learn 2500
Prefix count: total 0, learn 0, cfg 0

Border Status UP/DOWN AuthFail
3.3.3.3 ACTIVE UP 00:01:57 0
2.2.2.2 ACTIVE UP 00:02:14 0

Verification on R2 and R3
R2#show oer border
OER BR 2.2.2.2 ACTIVE, MC 1.1.1.1 UP/DOWN: UP 00:45:16,
Auth Failures: 0
Conn Status: SUCCESS, PORT: 3949
Exits
Et0/0 INTERNAL
Se1/0 EXTERNAL