Hi team,
I have a DMVPN setup with RUTX50 routers running RUTX_R_00.07.14.3. Each router has BGP sessions to two central routers with BGP running over GRE over IPsec using the RUTX50’s 4G interface. Between the hubs and the clients nhrp is used to resolve the next hop. This has been running fine for over a year.
We are now in the process of adding a wireless backup interface to each RUTX50. The issue I am running into now is that enabling the wireless interface causes instability in the overlay network, with the BGP sessions regularly bouncing, which rarely happened before (only in case of issues on the mobile network).
It turns out the RUTX50 resets the BGP connections each time the wireless (WAN) interface goes down, even though the wireless interface does not participate in any of the routing at all at this point. That is, the IP is assigned statically and no default route is associated to the wireless interface.
Looking at the system log, nhrpd is exiting (killed?) each time the wireless interface bounces for some reason (see the log below, edited for brevity).
Nhrpd restarting explains the resetting of the BGP sessions, the question is why does the wireless interface state change cause nhrpd to restart, and how can I prevent this from happening?
Note that the multi-wan / failover functionality is disabled.
Thanks in advance,
Regards, Anne
...[wireless interface goes down]...
8396 Fri Aug 1 12:17:56 2025 daemon.notice netifd: Network device 'wlan1-2' link is down
8397 Fri Aug 1 12:17:56 2025 daemon.notice netifd: Interface 'wan1' has link connectivity loss
8398 Fri Aug 1 12:17:56 2025 daemon.notice netifd: Interface 'wan1' is now down
...[snip wifi logs, interface comes back up]...
8421 Fri Aug 1 12:17:56 2025 daemon.notice netifd: Network device 'wlan1-2' link is up
8422 Fri Aug 1 12:17:57 2025 daemon.notice netifd: Interface 'wan1' has link connectivity
8423 Fri Aug 1 12:17:57 2025 daemon.notice netifd: Interface 'wan1' is setting up now
8424 Fri Aug 1 12:17:57 2025 daemon.info ipsec: 14[KNL] 192.168.127.65 appeared on wlan1-2
8425 Fri Aug 1 12:17:57 2025 kern.info kernel: [ 880.626580] wlan1-2: associated
8426 Fri Aug 1 12:17:57 2025 daemon.notice netifd: Interface 'wan1' is now up
...[snip dnsmasq logs]...
8438 Fri Aug 1 12:17:57 2025 kern.debug kernel: [ 880.660588] wlan1-2: Limiting TX power to 30 (30 - 0) dBm as advertised by 18:49:f8:6b:db:e0
8439 Fri Aug 1 12:17:57 2025 user.notice mwan3-hotplug[5775]: mwan3 hotplug on wan1 not called because interface disabled
8440 Fri Aug 1 12:17:57 2025 daemon.notice wpa_supplicant[4287]: wlan1-2: Associated with 18:49:f8:6b:db:e0
8441 Fri Aug 1 12:17:57 2025 daemon.notice wpa_supplicant[4287]: wlan1-2: CTRL-EVENT-SUBNET-STATUS-UPDATE status=0
8442 Fri Aug 1 12:17:58 2025 user.notice mwan3-hotplug[5958]: mwan3 hotplug on wan1 not called because interface disabled
8443 Fri Aug 1 12:17:58 2025 daemon.debug nhrpd[4721]: [MA774-4RDW4] Exiting...