[Bug 2142118] Re: Kernel 6.8.0-100: route cache corrupts external IPs as broadcast on systems with VLAN interfaces

It's confirm. I don't have any issues since I installed
6.8.0-103-generic

--
You received this bug notification because you are subscribed to linux
in Ubuntu.
Matching subscriptions: Bgg, Bmail, Nb
https://bugs.launchpad.net/bugs/2142118

Title:
Kernel 6.8.0-100: route cache corrupts external IPs as broadcast on
systems with VLAN interfaces

Status in linux package in Ubuntu:
New
Status in linux source package in Noble:
New

Bug description:
Description:
- Regression from: 6.8.0-94 (works) to 6.8.0-100 (broken)
- Setup: Dual default routes — physical interface (enp0s31f6, DHCP, metric 100) + VLAN (enp0s31f6.3, static, metric 200)
- Symptom: ip route get 8.8.8.8 returns broadcast 8.8.8.8 ... cache <local,brd> — kernel classifies external unicast IPs as
broadcast, blocking all outbound UDP/ICMP
- Impact: All outbound DNS, NTP, ping fail with "Permission denied"
- Workaround: sudo ip route flush cache temporarily fixes it, but it recurs
- Confirmed: Booting into 6.8.0-94 resolves the issue

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2142118/+subscriptions