Help is needed with understanding of Trigger level documentation



  • Hello all! This is a more linguistic question, I'm not a native English speaker and the exact meaning of this sentence isn't clear to me:

    "Marks the gateway as down only when it is completely down, past one or both of the higher thresholds configured for the gateway."

    This is for "member down" option

    More precisely: "past one or both" - what does it mean here? Is it means that it triggered just for "link down" and complerely ignores thresholds in any combination? This is pretty logical, but It's better to check.

    Many thanks in advance!



  • @n0153 said in Help is needed with understanding of Trigger level documentation:

    More precisely: "past one or both" - what does it mean here? Is it means that it triggered just for "link down" and complerely ignores thresholds in any combination?

    A system "LINK DOWN" will do it's job, but there are others reasons why an interface - when it part of a gateway - should be considered "down" (even when it's up and working fine) :

    There is a program called 'pinger' - here it is :

    ps ax | grep pinger
    78946  -  Is      0:15.89 /usr/local/bin/dpinger -S -r 0 -i WAN_DHCP -B 192.168
    79307  -  Is      0:25.29 /usr/local/bin/dpinger -S -r 0 -i HE_TUN_TUNNELV6 -B
    

    that send out regular ping requests. It measures the return time, deviation, etc.
    This :

    past one or both of the higher thresholds
    

    means that if the (time ?) value of one of the (ping) replies goes out of range (thresholds)
    the action will be taken.

    So, the phrase looks ok to me.

    Btw : I'm not an native English speaker neither ;)



  • Thanks for the answer! So the difference between "Member Down" and "Packet Loss or High Latency" is that the first of them immediately reach the "down" state, before pinger collect needed data?



  • When the WAN cable is ripped out, or the router (or modem) up stream goes down, the NIC will signal a LINK DOWN.
    No need for pinger to determine if ICMP packets come back, and measure the time. They won't come back, they can't even been send away.
    That's an event that will take down the gateway in the routing table.

    pinger, can detect if there is an upstream problem, and uses ICMP packets to detect if the upstream path is available. If it is to bad, the gateway is likewise considered as down.



  • @Gertjan said in Help is needed with understanding of Trigger level documentation:

    When the WAN cable is ripped out, or the router (or modem) up stream goes down, the NIC will signal a LINK DOWN.
    No need for pinger to determine if ICMP packets come back, and measure the time. They won't come back, they can't even been send away.
    That's an event that will take down the gateway in the routing table.

    pinger, can detect if there is an upstream problem, and uses ICMP packets to detect if the upstream path is available. If it is to bad, the gateway is likewise considered as down.

    And this is exactly for the case when "Member Down" is selected, right? So it triggers to the "down" state when ping is bad, despite the fact that the link associated to this interface is "up"? Someone actually verified this by an experiment? I cannot do this right now because I have no test environment, just production.


Log in to reply