Lower customer local-preference from 300 to 250¶
Case 9 of the Network Change Verdict Corpus. Category: traffic-engineering. Expected verdict: safe (an experienced operator would approve it).
Why it is expected safe¶
Customer routes stay the most preferred (peer 200, upstream 100).
The config change¶
Against the FRR configs of the base lab:
--- a/pe1.conf
+++ b/pe1.conf
@@ -27,7 +27,7 @@
route-map FROM-CUSTOMER permit 10
match ip address prefix-list CUSTOMER-IN
set community 65000:100
- set local-preference 300
+ set local-preference 250
!
route-map FROM-UPSTREAM permit 10
set community 65000:200
What each strategy said¶
The expected verdict was committed to git before any run. All three strategies tested the same running lab (method).
| Strategy | Verdict | Result | Checks that failed |
|---|---|---|---|
| Ping only | safe | ✅ | none |
| All BGP sessions up | safe | ✅ | none |
| Netdryrun intent checks | safe | ✅ | none |
What Netdryrun flagged¶
Nothing: every check in the intent spec passed, so Netdryrun called the change safe.
Reproduce it¶
On Linux or WSL2 with Docker and containerlab, from a checkout of the repository:
Case file: corpus/cases/09-customer-localpref.yml. Published result: netdryrun 0.2.0, containerlab 0.81.1, FRR quay.io/frrouting/frr:10.4.1, commit ec23379, run on 2026-10-26.