X-Git-Url: http://git.grml.org/?a=blobdiff_plain;f=grml_tips;h=60672708c6623d3b712f766bf486554dbfb857d9;hb=55d6355598571146f12f92ed1e87229e2c07a69e;hp=7825e12696d1122b1e1385410392e20820cc4879;hpb=2a869a51f5eb5fed53a0bf6b745372639af0f13b;p=grml-tips.git diff --git a/grml_tips b/grml_tips index 7825e12..6067270 100644 --- a/grml_tips +++ b/grml_tips @@ -2148,7 +2148,7 @@ Restore the backup using unzsplit: More usage examples: man zsplit + man unzsplit -- -Measure network performance using ipserf +Measure network performance using iperf: Server side: % iperf -s -V @@ -2569,3 +2569,53 @@ UTF-8 at grml / some general information regarding Unicde/UTF-8: http://wiki.grml.org/doku.php?id=utf8 -- + +This allows one ssh connection attepmt per minute per source ip, with a initial +burst of 10. The available burst is like a counter which is initialised with +10. Every connection attempt decrements the counter, and every minute where the +connection limit of one per minute is not overstepped the counter is +incremented by one. If the burst counter is exhausted the real rate limit +comes into play. This gives you 11 connectionattepmts in the first minute +before blocked for 10minutes. After 10 minutes block the game restarts. + +Hint: you could set the burst value to 5 and the block time to only 5 minutes +to achive the same average connection rate but with halve the block time. + +iptables -A inet_in -p tcp --syn --dport 22 -m hashlimit --hashlimit-name ssh \ + --hashlimit 1/minute \ --hashlimit-burst 10 --hashlimit-mode srcip \ + --hashlimit-htable-expire 600000 -j ACCEPT +iptables -A inet_in -p tcp --dport 22 -m state --state NEW -j REJECT +-- +Tunnel a specific connection via socat: + +On the client: +% socat TCP4-LISTEN:8003 TCP4:gateway:500 + +On the gateway: +# socat TCP4-LISTEN:500,fork TCP4:target:$PORT + +Using localhost:8003 on the client uses the tunnel now. +-- +Set date: + +# date --set=060916102007 + +where the bits are month(2)/day(2)/hour(2)/minute(2)/year(4) + +Set date using a relative date: + +# date -s '+3 mins' + +or + +# date -s '+tomorrow' + +Display a specific relative date: + +# date -d '+5 days -2 hours' + +Don't forget to set hardware clock via: + +# hwlock -w +-- +