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====== Supervision ====== | ====== Supervision ====== | ||
===== Introduction ===== | ===== Introduction ===== | ||
- | This note descibes | + | {{: |
+ | This note describes | ||
+ | functionality. | ||
- | The NetModule Routers are designed for high reliability and 24x7 operations. To guarantee best connection availability several levels and methods of supervision are used. | + | The NetModule Routers are designed for high reliability and 24x7 operations. To guarantee best connection availability |
+ | several levels and methods of supervision are used. | ||
- | Depending on your hardware model, WAN links can be made up of either Wireless Wide Area Network (WWAN), Wireless LAN (WLAN), Ethernet or PPP over Ethernet (PPPoE) connections. | + | Depending on your hardware model, WAN links can be made up of either Wireless Wide Area Network (WWAN), |
+ | Wireless LAN (WLAN), Ethernet or PPP over Ethernet (PPPoE) connections. | ||
- | The highes | + | The highest |
+ | link as well generic for any link based on the routing table. The user can define up to two host which are pinged | ||
+ | every "ping interval" | ||
+ | milliseconds a retry is done using the "retry interval" | ||
+ | If still there is no answer the defined emergency action is executed. It's recommended to set " | ||
+ | on each link pinging the next hop e.g. the access point for a WiFi client link. | ||
+ | Restarting the link service means, that it will be tried to re-establish the link e.g. redial on a modem connection. | ||
+ | Emergency action " | ||
+ | If you are using a VPN you should also enable the dead pear detection or keep alive mechanisms. | ||
+ | For the generic link " | ||
+ | This ping will ensure that even interruptions in the back-bone can be detected and a full point-to-point connection | ||
+ | is guaranteed. | ||
- | The** WWAN Manager** who is responsible for the control of the mobile network modems checks every 15 seconds if the connection is still established. Different informations like configurable signal | + | The** WWAN Manager** who is responsible for the control of the mobile network modems checks every 15 seconds |
+ | if the connection is still established. Different informations like configurable signal | ||
+ | network registration status of service type are used to determine the status of the modem links. | ||
- | + | The task of the **Link Manager** is to verify if a link is up or down and to select highest priority | |
+ | link as the so-called hotlink which holds the default route for outgoing packets. | ||
+ | Every 5 seconds he checks for each active link if the following conditions are met: | ||
- | + | ^Condition^ WWAN^ WLAN^ ETH^ PPPoE^ | |
+ | |Modem is registered | X | | | | ||
+ | |Registered with valid service type | X | | | | | ||
+ | |Valid SIM state | X | | | | | ||
+ | |Sufficient signal strength | X | X | | | | ||
+ | |Client is associated | X | | | | | ||
+ | |Client is authenticated | X | | | | | ||
+ | |Valid DHCP address retrieved | X | X | X | X | | ||
+ | |Link is up and holds address | X | X | X | X | | ||
+ | |Ping check succeeded | X | X | X | X | | ||
- | + | If at least one condition of a link is not met, the link manager counts the number of subsequent failures. | |
+ | WWAN links are marked as down after 5 subsequent failures, PPPoE after three, WiFi and Ethernet after one. | ||
+ | The highest priority link which is up will become the so-called hotlink which holds the default route for | ||
+ | outgoing packets. Of course the link manager will change the hotlink as soon a higher priority interface comes up. | ||
+ | Finaly a **Hardware Watchdog** is available which will restart the device if he is not retriggered after x seconds. | ||
+ | The Router Suppervision deamon checks permanently if all components of the router application are still alive. | ||
+ | So in the unlikely case that the operating systems or the router software has an internal error the system restarts | ||
+ | completely by rebooting. This is the only condition where the system will reboot except " | ||
+ | is configured in the link supervision. | ||
+ | |||
+ | ===== Summary ===== | ||
+ | - Level 4: VPN dead peer detection/ | ||
+ | * Is VPN link over WAN link healthy? See also [[sdk: | ||
+ | - Level 3: Link level Ping Supervision | ||
+ | * Is link to next network node healthy? | ||
+ | - Level 2: Modem/WiFi Supervision | ||
+ | * Is modem ok, device registered and a sufficient signal available ? | ||
+ | - Level 1: Link Supervison | ||
+ | * Is physical link up or physical connection ok? | ||
+ | - Level 0: Hardware Watchdog | ||
+ | * Is router firmware and operating system running ok? | ||
- | |||
- | {{ : | + | ===== Configuration ===== |
+ | {{ : |