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yujqiao/count_clients.sh

Created September 21, 2022 05:03
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  1. yujqiao renamed this gist Sep 21, 2022. 1 changed file with 0 additions and 0 deletions.
    0 gistfile1.txt → count_clients.sh
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  2. yujqiao created this gist Sep 21, 2022.
    35 changes: 35 additions & 0 deletions gistfile1.txt
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    #!/bin/sh
    mac_blacklist="01:00:8c:fa:1a:ae:d1"

    leases=$(cat /tmp/dhcp.leases | sed 's/*/unknown/')

    IFS='
    '

    online_cnt=0
    # grep NUD status, see also https://www.ccexpert.us/routing-tcp-ip-2/neighbor-unreachability-detection.html
    ip nei | grep -E "(REACHABLE)|(DELAY)" > /tmp/arp_table
    for line in $leases
    do
    ip=$(echo $line | awk '{print $3}')
    name=$(echo $line | awk '{print $4}')
    mac=$(echo $line | awk '{print $5}')
    if ( grep "$ip" /tmp/arp_table > /dev/null)
    then
    valid=1
    for black in $mac_blacklist
    do
    if [[ $black = $mac ]]
    then
    valid=0
    fi
    done
    if [[ $valid -eq 1 ]]
    then
    echo $ip "$name" "$mac"
    online_cnt=$((online_cnt + 1))
    fi
    fi
    done

    return $online_cnt