我收到很多类似的消息：
Jun 23 10:24:20 awakening kernel: [ 1691.596823] xt_TCPMSS: bad length (1492 bytes)
Jun 23 10:24:21 awakening kernel: [ 1692.663362] xt_TCPMSS: bad length (1448 bytes)
Jun 23 10:24:21 awakening kernel: [ 1692.663495] xt_TCPMSS: bad length (1448 bytes)
Jun 23 10:24:21 awakening kernel: [ 1692.663588] xt_TCPMSS: bad length (1448 bytes)
Jun 23 10:24:21 awakening kernel: [ 1692.663671] xt_TCPMSS: bad length (1440 bytes)
Jun 23 10:24:26 awakening kernel: [ 1697.062914] xt_TCPMSS: bad length (474 bytes)
Jun 23 10:24:26 awakening kernel: [ 1697.305525] xt_TCPMSS: bad length (1492 bytes)
Jun 23 10:24:27 awakening kernel: [ 1698.946633] xt_TCPMSS: bad length (1492 bytes)
Jun 23 10:24:36 awakening kernel: [ 1707.481198] xt_TCPMSS: bad length (1492 bytes)
Jun 23 10:24:37 awakening kernel: [ 1708.723526] xt_TCPMSS: bad length (805 bytes)
Jun 23 10:24:38 awakening kernel: [ 1709.599461] xt_TCPMSS: bad length (805 bytes)
Jun 23 10:24:41 awakening kernel: [ 1712.211052] xt_TCPMSS: bad length (1492 bytes)
Jun 23 10:24:41 awakening kernel: [ 1712.260588] xt_TCPMSS: bad length (1492 bytes)
Jun 23 10:24:41 awakening kernel: [ 1712.976058] xt_TCPMSS: bad length (1492 bytes)
Jun 23 10:24:43 awakening kernel: [ 1714.225209] xt_TCPMSS: bad length (1492 bytes)
Jun 23 10:24:43 awakening kernel: [ 1714.914961] xt_TCPMSS: bad length (1492 bytes)
Jun 23 10:24:55 awakening kernel: [ 1726.192696] xt_TCPMSS: bad length (1480 bytes)
Jun 23 10:24:55 awakening kernel: [ 1726.192825] xt_TCPMSS: bad length (1480 bytes)
在我的 dmesg/syslog 中。这台 Linux 机器除其他用途外还用作互联网网关。连接通过 PPPoE。我的 iptables 脚本中有以下行：
$IPT -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu # PPPoE fix
几天前，当我从 Debian lenny 2.6.27 升级到 squeeze 2.6.32 时，出现此消息的频率增加了 10 倍。为什么我会看到此消息？我该如何修复它们？
答案1
我通过从 FW 脚本中删除 TCPMSS 行解决了该问题。显然，当建立 PPP 连接时，PPP 系统已将一行添加到 iptables 中。