Regular ping against WAN subnet



  • Hi

    I used tcpdump to watch ICMP traffic on my external WAN interface (using ng0 since I'm connecting using PPPoE) when I noticed that my pfsense box regularily pings the WAN subnet.
    Why is this necessary? Some kind of keep alive? Is it possible to turn it off?

    18:36:19.459482 IP 87.248.7.36 > 87.248.0.0: ICMP echo request, id 28753, seq 0, length 64
    18:36:19.468208 IP 87.248.0.0 > 87.248.7.36: ICMP echo reply, id 28753, seq 0, length 64
    18:36:20.460176 IP 87.248.7.36 > 87.248.0.0: ICMP echo request, id 28753, seq 1, length 64
    18:36:20.471666 IP 87.248.0.0 > 87.248.7.36: ICMP echo reply, id 28753, seq 1, length 64
    18:36:21.461192 IP 87.248.7.36 > 87.248.0.0: ICMP echo request, id 28753, seq 2, length 64
    18:36:21.469646 IP 87.248.0.0 > 87.248.7.36: ICMP echo reply, id 28753, seq 2, length 64
    18:36:22.462209 IP 87.248.7.36 > 87.248.0.0: ICMP echo request, id 28753, seq 3, length 64
    18:36:22.470250 IP 87.248.0.0 > 87.248.7.36: ICMP echo reply, id 28753, seq 3, length 64
    18:36:23.463232 IP 87.248.7.36 > 87.248.0.0: ICMP echo request, id 28753, seq 4, length 64
    18:36:23.471354 IP 87.248.0.0 > 87.248.7.36: ICMP echo reply, id 28753, seq 4, length 64
    18:37:20.570833 IP 87.248.7.36 > 87.248.0.0: ICMP echo request, id 52049, seq 0, length 64
    18:37:20.581006 IP 87.248.0.0 > 87.248.7.36: ICMP echo reply, id 52049, seq 0, length 64
    18:37:21.575254 IP 87.248.7.36 > 87.248.0.0: ICMP echo request, id 52049, seq 1, length 64
    18:37:21.583097 IP 87.248.0.0 > 87.248.7.36: ICMP echo reply, id 52049, seq 1, length 64
    18:37:22.576270 IP 87.248.7.36 > 87.248.0.0: ICMP echo request, id 52049, seq 2, length 64
    18:37:22.584072 IP 87.248.0.0 > 87.248.7.36: ICMP echo reply, id 52049, seq 2, length 64
    18:37:23.577286 IP 87.248.7.36 > 87.248.0.0: ICMP echo request, id 52049, seq 3, length 64
    18:37:23.585300 IP 87.248.0.0 > 87.248.7.36: ICMP echo reply, id 52049, seq 3, length 64
    18:37:24.578303 IP 87.248.7.36 > 87.248.0.0: ICMP echo request, id 52049, seq 4, length 64
    18:37:24.586779 IP 87.248.0.0 > 87.248.7.36: ICMP echo reply, id 52049, seq 4, length 64



  • That is probably the ping for RRD's quality graph metric.
    Every minute or so it will issue a few ping packets to check how the latency/packet loss to the WAN gateway is like.


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