Here is a log I have captured today regarding my tethering failing. It appears to be related to DHCP not working properly. Once the lease expires, the connection drops.
Mon Jan 20 18:19:00 2025 daemon.notice netifd: tethering (941): udhcpc: received SIGTERM
Mon Jan 20 18:19:00 2025 daemon.notice netifd: tethering (941): udhcpc: entering released state
Mon Jan 20 18:19:00 2025 daemon.notice netifd: tethering (941): Command failed: Permission denied
Mon Jan 20 18:19:00 2025 daemon.notice netifd: Interface 'tethering' is now down
Mon Jan 20 18:19:00 2025 daemon.notice netifd: Interface 'tethering' is disabled
Mon Jan 20 18:19:00 2025 daemon.notice netifd: Interface 'tethering' has link connectivity loss
Mon Jan 20 18:19:00 2025 user.notice firewall: Reloading firewall due to ifdown of tethering ()
Mon Jan 20 18:19:00 2025 user.notice kmwan: config json str={ "op": 3, "data": { "cells": [ "tethering" ] } }
Mon Jan 20 18:19:02 2025 daemon.notice netifd: Interface 'tethering' is enabled
Mon Jan 20 18:19:02 2025 daemon.notice netifd: Interface 'tethering' has link connectivity
Mon Jan 20 18:19:02 2025 daemon.notice netifd: Interface 'tethering' is setting up now
Mon Jan 20 18:19:02 2025 daemon.notice netifd: tethering (14776): udhcpc: started, v1.33.2
Mon Jan 20 18:19:02 2025 daemon.notice netifd: tethering (14776): udhcpc: sending discover
Mon Jan 20 18:19:02 2025 daemon.notice netifd: tethering (14776): udhcpc: sending select for 172.20.10.6
Mon Jan 20 18:19:02 2025 daemon.notice netifd: tethering (14776): udhcpc: lease of 172.20.10.6 obtained, lease time 3600
Mon Jan 20 18:19:02 2025 daemon.notice netifd: Interface 'tethering' is now up
Mon Jan 20 18:19:02 2025 user.notice firewall: Reloading firewall due to ifup of tethering (eth2)
Mon Jan 20 18:19:02 2025 user.notice kmwan: config json str={ "op": 2, "data": { "cells": [ { "interface": "tethering", "netdev": "eth2", "track_mode": "force", "addr_type": 4, "tracks": [ { "type": "ping", "ip": "1.1.1.1" }, { "type": "ping", "ip": "8.8.8.8" }, { "type": "ping", "ip": "208.67.222.222" }, { "type": "ping", "ip": "208.67.220.220" } ] } ] } }
Mon Jan 20 18:19:02 2025 kern.debug kernel: [2103637.507755] [add_dev_config 303]add node success. iface:tethering, dev:eth2, ifindex:47
Mon Jan 20 18:49:02 2025 daemon.notice netifd: tethering (14776): udhcpc: sending renew to 172.20.10.1
Mon Jan 20 19:04:02 2025 daemon.notice netifd: tethering (14776): udhcpc: sending renew to 172.20.10.1
Mon Jan 20 19:11:32 2025 daemon.notice netifd: tethering (14776): udhcpc: sending renew to 172.20.10.1
Mon Jan 20 19:15:17 2025 daemon.notice netifd: tethering (14776): udhcpc: sending renew to 172.20.10.1
Mon Jan 20 19:17:09 2025 daemon.notice netifd: tethering (14776): udhcpc: sending renew to 172.20.10.1
Mon Jan 20 19:18:05 2025 daemon.notice netifd: tethering (14776): udhcpc: sending renew to 0.0.0.0
Mon Jan 20 19:18:33 2025 daemon.notice netifd: tethering (14776): udhcpc: sending renew to 0.0.0.0
Mon Jan 20 19:18:47 2025 daemon.notice netifd: tethering (14776): udhcpc: sending renew to 0.0.0.0
Mon Jan 20 19:18:54 2025 daemon.notice netifd: tethering (14776): udhcpc: sending renew to 0.0.0.0
Mon Jan 20 19:18:58 2025 daemon.notice netifd: tethering (14776): udhcpc: sending renew to 0.0.0.0
Mon Jan 20 19:18:59 2025 daemon.notice netifd: tethering (14776): udhcpc: sending renew to 0.0.0.0
Mon Jan 20 19:18:59 2025 daemon.notice netifd: tethering (14776): udhcpc: lease lost, entering init state
Mon Jan 20 19:18:59 2025 daemon.notice netifd: Interface 'tethering' has lost the connection
Mon Jan 20 19:18:59 2025 daemon.notice netifd: tethering (14776): udhcpc: sending discover
Mon Jan 20 19:18:59 2025 user.notice firewall: Reloading firewall due to ifdown of tethering ()
Mon Jan 20 19:18:59 2025 user.notice kmwan: config json str={ "op": 3, "data": { "cells": [ "tethering" ] } }
Mon Jan 20 19:18:59 2025 kern.debug kernel: [2107233.580851] kmwan: Delete node:tethering
Mon Jan 20 19:19:02 2025 daemon.notice netifd: tethering (14776): udhcpc: sending discover
Mon Jan 20 21:58:53 2025 daemon.notice netifd: tethering (14776): udhcpc: received SIGTERM
Mon Jan 20 21:58:53 2025 daemon.notice netifd: tethering (14776): udhcpc: entering released state
Mon Jan 20 21:58:53 2025 daemon.notice netifd: tethering (14776): Command failed: Permission denied
Mon Jan 20 21:58:53 2025 daemon.notice netifd: Interface 'tethering' is now down
Mon Jan 20 21:58:53 2025 daemon.notice netifd: Interface 'tethering' is disabled
Mon Jan 20 21:58:53 2025 daemon.notice netifd: Interface 'tethering' has link connectivity loss
Mon Jan 20 21:58:53 2025 user.notice firewall: Reloading firewall due to ifdown of tethering ()
Mon Jan 20 21:58:54 2025 user.notice kmwan: config json str={ "op": 3, "data": { "cells": [ "tethering" ] } }
Mon Jan 20 21:58:54 2025 daemon.notice netifd: Interface 'tethering' is enabled
Mon Jan 20 21:58:54 2025 daemon.notice netifd: Interface 'tethering' has link connectivity
Mon Jan 20 21:58:54 2025 daemon.notice netifd: Interface 'tethering' is setting up now
Mon Jan 20 21:58:54 2025 daemon.notice netifd: tethering (23738): udhcpc: started, v1.33.2
Mon Jan 20 21:58:54 2025 daemon.notice netifd: tethering (23738): udhcpc: sending discover
Mon Jan 20 21:58:54 2025 daemon.notice netifd: tethering (23738): udhcpc: sending select for 172.20.10.6
Mon Jan 20 21:58:54 2025 daemon.notice netifd: tethering (23738): udhcpc: lease of 172.20.10.6 obtained, lease time 3600
Mon Jan 20 21:58:54 2025 daemon.notice netifd: Interface 'tethering' is now up
Mon Jan 20 21:58:55 2025 user.notice firewall: Reloading firewall due to ifup of tethering (eth2)
Mon Jan 20 21:58:55 2025 user.notice kmwan: config json str={ "op": 2, "data": { "cells": [ { "interface": "tethering", "netdev": "eth2", "track_mode": "force", "addr_type": 4, "tracks": [ { "type": "ping", "ip": "1.1.1.1" }, { "type": "ping", "ip": "8.8.8.8" }, { "type": "ping", "ip": "208.67.222.222" }, { "type": "ping", "ip": "208.67.220.220" } ] } ] } }
Mon Jan 20 21:58:55 2025 kern.debug kernel: [2116826.964003] [add_dev_config 303]add node success. iface:tethering, dev:eth2, ifindex:47
I am using an iPhone SE on AT&T for this connection.
I manually aborted the connection and restarted it, thus you see a successful reconnection. I am running 4.7 latest beta. IOS 18.2.1 (current - has been happening for a while though).