bash Nmap - RTTVAR 已经增长到超过 2.3 秒，减少到 2.0
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Nmap - RTTVAR has grown to over 2.3 seconds, decreasing to 2.0
提问by cflinspach
I have a script that I'm using to build a config for icinga2. The network is large, multiple /13's large. When I run the script I keep getting the RTTVAR has grown to over 2.3 seconds, decreasing to 2.0 error. I've tried raising my gc_thresh and breaking up the subnets. I've dived through the little info from google and can't seem to find a fix. If anyone has any ideas, I'd really appreciate it. I'm on Ubuntu 16.04
我有一个脚本，用于为 icinga2 构建配置。网络很大，多个/13 的大。当我运行脚本时，我不断发现 RTTVAR 已经增长到超过 2.3 秒，减少到 2.0 错误。我试过提高我的 gc_thresh 并分解子网。我已经浏览了谷歌的小信息，似乎找不到解决办法。如果有人有任何想法，我将不胜感激。我在 Ubuntu 16.04
My script:
我的脚本：
# Find devices and create IP list
i=72
while [ $i -lt 255 ]
do
echo "$(date) - Scanning xx.$i.0.0/16" >> files/scan.log
nmap -sn --host-timeout 5 xx.$i.0.0/16 -oG - | awk '/Up$/{print }' >> files/ip-list
let i=i+1
done
My /etc/sysctl.conf
我的 /etc/sysctl.conf
# Force gc to clean-up quickly
net.ipv4.neigh.default.gc_interval = 3600
# Set ARP cache entry timeout
net.ipv4.neigh.default.gc_stale_time = 3600
# Setup DNS threshold for arp
net.ipv4.neigh.default.gc_thresh3 = 8192
net.ipv4.neigh.default.gc_thresh2 = 4096
net.ipv4.neigh.default.gc_thresh1 = 2048
Edit: added host-timeout 5 removed -n
编辑：添加主机超时 5 删除 -n
回答by OscarAkaElvis
I can suggest you tu use ping scan. If you want an "overall sight" of your network you can use
我可以建议你使用 ping 扫描。如果您想要网络的“整体视野”，您可以使用
nmap -sP -n
It decreases the time a little bit comparing to nmap -sn , you can check it with small examples.
与 nmap -sn 相比，它减少了一点时间，您可以通过小示例进行检查。
As I said in a comment. Use --host-timeout and --max-retries and that will improve your performance.
正如我在评论中所说。使用 --host-timeout 和 --max-retries 可以提高你的性能。
