Linux
“net_ratelimit:44 個回調被抑制”在 Linux 上是什麼意思?
我正在嘗試在基於 Debian 的路由器上調整 Snort 性能。我看到了類似的東西:
snort packet recv contents failure: No buffer space available
所以我將緩衝區提高到 8M,當這不起作用時,我嘗試了 16M,根據http://fasterdata.es.net/fasterdata/host-tuning/linux/上的調整指南:
#!/bin/sh -e # # rc.local # # This script is executed at the end of each multiuser runlevel. # Make sure that the script will "exit 0" on success or any other # value on error. # # In order to enable or disable this script just change the execution # bits. # # By default this script does nothing. # Increase TCP Buffers to 16 MB sysctl -w net.core.rmem_default='16777216' sysctl -w net.core.wmem_default='16777216' sysctl -w net.core.rmem_max='16777216' sysctl -w net.core.wmem_max='16777216' sysctl -w net.ipv4.tcp_wmem='1048576 4194304 16777216' sysctl -w net.ipv4.tcp_rmem='1048576 4194304 16777216' sysctl -w net.core.netdev_max_backlog='30000' exit 0
現在我看不到“無緩衝區空間”日誌條目,但我有一個新條目:
net_ratelimit: 44 callbacks suppressed
來自同一時間框架的唯一其他資訊是這些火星人,也許這就是被壓制的東西?
Jun 4 07:09:36 ilium ntpd_intres[3575]: host name not found: 0.us.pool.ntp.org Jun 4 14:17:36 ilium kernel: [25743.259951] net_ratelimit: 44 callbacks suppressed Jun 4 14:17:36 ilium kernel: [25743.259955] martian source 216.59.11.21 from 127.0.0.1, on dev eth0 Jun 4 14:17:36 ilium kernel: [25743.259956] ll header: 00:30:48:7c:f8:10:00:24:c4:49:8d:00:08:00 Jun 4 14:17:58 ilium kernel: [25765.055449] martian source 216.59.11.21 from 127.0.0.1, on dev eth0 Jun 4 14:17:58 ilium kernel: [25765.055451] ll header: 00:30:48:7c:f8:10:00:24:c4:49:8d:00:08:00 Jun 4 14:18:43 ilium kernel: [25809.998978] martian source 216.59.11.21 from 127.0.0.1, on dev eth0 Jun 4 14:18:43 ilium kernel: [25809.998980] ll header: 00:30:48:7c:f8:10:00:24:c4:49:8d:00:08:00 Jun 4 14:24:11 ilium kernel: [26138.700143] martian source 216.59.11.71 from 127.0.0.1, on dev eth0 Jun 4 14:24:11 ilium kernel: [26138.700145] ll header: 00:30:48:7c:f8:10:00:24:c4:49:8d:00:08:00 Jun 4 14:28:42 ilium kernel: [26409.130701] martian source 216.59.11.71 from 127.0.0.1, on dev eth0 Jun 4 14:28:42 ilium kernel: [26409.130703] ll header: 00:30:48:7c:f8:10:00:24:c4:49:8d:00:08:00
’
net_ratelimit()
’ 用於限制來自核心的 syslog 消息。這個“回調被抑制”消息意味著它抑制了 44 條系統日誌消息。
這是為了避免載入您的 syslog 日誌記錄路徑。
如果您有興趣,這裡是原始碼參考,
FreeBSD/Linux Kernel Cross Reference;sys/net/core/utils.c ,
它呼叫sys/lib/ratelimit.c –
___ratelimit()
您可能想調查您的“火星來源”,
但我猜如果您忽略它,速率限制將處理日誌
(修復未知日誌來源通常是個好主意)。
在你的情況下,它看起來就像你的火星包,
一個傳入或傳出數據包,其源或目標地址在 127.0.0.0/8 範圍內,保留用於主機內的環回。