[Plugins-writers] RE: Nessus not scanning

From: JHORVAT1@private
Date: Fri Jan 30 2004 - 07:50:00 PST

  • Next message: Renaud Deraison: "Re: Nessus not scanning"

    I am having issues somewhat similar to what Ravi was seeing.  I want to enable
    the "Ping the remost host" option to do an ICMP ping because I'm scanning
    large subnets and want to move on quickly if something doesn't appear to be
    up.  The "Ping the remote host" option calls ping_host.nasl, and using
    Ethereal I found what seems to be the problem.  Nessus sends out an ICMP echo
    request, but hosts never reply, apparently because the IP header checksum in
    the ICMP packet is 0!  The relevant part of ping_host.nasl is below (sorry if
    the formatting is goofy):
    ip = forge_ip_packet(ip_v:4, ip_hl:5, ip_tos:0,ip_off:0,ip_len:20,
    			ip_p:IPPROTO_ICMP, ip_id:id, ip_ttl:0x40,
    icmp = forge_icmp_packet(ip:ip, icmp_type:8, icmp_code:0,
    			icmp_seq: 1, icmp_id:1);
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