Subject: [PATCH net-next] selftests: net: do not detect PPPoX loopback

From: Qingfang Deng <[email-masked]>
Date: Wed, 3 Jun 2026 14:17:44 +0800

By default, pppd attempts to detect loopbacks on the underlying
interface using a pseudo-randomly generated magic number and checks if
the same value is received. The seed for the PRNG is a hash of hostname
XOR current time XOR pid, which is likely to collide on NIPA, causing
false positives. Disable magic number generation.

Reported-by: Matthieu Baerts <[email-masked]>
Fixes: 7af2a94f4dcf ("selftests: net: add tests for PPPoL2TP")
Signed-off-by: Qingfang Deng <[email-masked]>
---
 tools/testing/selftests/net/ppp/pppoe-server-options | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/testing/selftests/net/ppp/pppoe-server-options b/tools/testing/selftests/net/ppp/pppoe-server-options
index 66c8c9d319e9..cd586be7061b 100644
--- a/tools/testing/selftests/net/ppp/pppoe-server-options
+++ b/tools/testing/selftests/net/ppp/pppoe-server-options
@@ -1,2 +1,3 @@
 noauth
 noipdefault
+nomagic
-- 
2.43.0