👨‍💻 当Linux系统出现随机断网、网络速度慢等问题时，可能是由于ARP表溢出导致的。ARP表溢出意味着ARP表已达到其最大允许限制，无法再学习新的ARP条目。 在/var/log/messages文件中，您可能会看到以下记录： kernel: Neighbour table overflow. 该记录表明ARP表已溢出。

⚙️ 为了解决ARP表溢出问题，您可以采取以下两种方法： * **修改/etc/sysctl.conf文件：** 在该文件中添加以下行以调整ARP表限制： net.ipv4.neigh.default.gc_thresh1=1024 net.ipv4.neigh.default.gc_thresh2=4096 net.ipv4.neigh.default.gc_thresh3=16384 * **临时调整ARP表限制：** 使用以下命令临时调整ARP表限制，这些更改将在系统重启后失效： # echo 1024 > /proc/sys/net/ipv4/neigh/default/gc_thresh1 # echo 4096 > /proc/sys/net/ipv4/neigh/default/gc_thresh2 # echo 16384 > /proc/sys/net/ipv4/neigh/default/gc_thresh3

🕵️‍♀️ 文章解释了ARP表工作原理，以及三个参数的作用： * **gc_thresh1：** 设置ARP缓存中的最小ARP条目数量。如果未达到此值，GC不会运行。 * **gc_thresh2：** 设置ARP缓存中的软最大ARP条目数量。GC允许ARP缓存超过此限制5秒，然后开始清理。 * **gc_thresh3：** 设置ARP缓存中的硬限制。达到此限制后，将不再添加新的ARP条目。

🚀 了解ARP表溢出问题的原因和解决方法，可以帮助您更好地维护Linux系统，提高系统稳定性和网络性能。

Not specific to the Checkpoint but rather any Linux-based system issue Problem  usually shows itself in randomly distributed inability of stations to pass the firewall, slowness and other network problems follow.
In /var/log/message you see the following record:
kernel: Neighbour table overflow.
That means ARP table has reached its maximum allowed limit and no new ARP entries are being learnt.

You can either find reason for sudden ARP requests influx or adjust ARP table limits accordingly.The default maximum value for Gaia is 4096.
You adjust ARP table limits either editing  this file (then change survives reboot):

/etc/sysctl.conf
If not present add these lines at the end, and try not to delete by mistake anything:

net.ipv4.neigh.default.gc_thresh1 = 1024  net.ipv4.neigh.default.gc_thresh2 = 4096  net.ipv4.neigh.default.gc_thresh3 = 16384  

Then issue command:
# sysctl -p Or if you want to increase it temporarily until reboot:

#echo 1024 > /proc/sys/net/ipv4/neigh/default/gc_thresh1#echo 4096 > /proc/sys/net/ipv4/neigh/default/gc_thresh2#echo 16384 > /proc/sys/net/ipv4/neigh/default/gc_thresh3

And the short explanation follows.
gc in the above means Garbage Collector (GC).
net.ipv4.neigh.default.gc_thresh1  - sets minimum number of ARP entries in the cache.Until this value is reached GC doesnt run at all.
net.ipv4.neigh.default.gc_thresh2  - sets soft maximum number of ARP entries in the cache.GC allows ARP cache to pass this limit for 5 seconds and then starts cleaning.
net.ipv4.neigh.default.gc_thresh3  -  sets hard limit of ARP entries in the cache.After it is reached no more ARP entries are being added.

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