Differences

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--- linux:networking [2013/10/25 12:56]
pegasus [Per user traffic accounting]
+++ linux:networking [2014/08/21 10:27]
zagi [TCP Tunning (linux kernel)]
@@ Line 1: / Line 1: @@
 ====== Linux networking ======
+===== Usefull links =====
-=== Usefull links ===
   * [[http://linux-net.osdl.org/index.php/Main_Page|LinuxNet]] - a good place where to begin
   * [[http://www.lartc.org/|Linux Advanced Routing & Traffic Control]]
@@ Line 28: / Line 28: @@
 ===== TCP Tunning (linux kernel) =====
+Change initial tcp window:
+  ip route | while read p; do ip route change $p initcwnd 20 initrwnd 20; done
 {{page>linux:sysctl#2.6 net/ipv4 options}}
@@ Line 187: / Line 192: @@
-==== Per user traffic accounting ====
-Modern times require you to know how much traffic each user on a system is generating. A lightweight and unobtrusive way to do it is:
-<code bash>
-iptables -A PREROUTING -t mangle -j CONNMARK --restore-mark
-for interesting user in /etc/passwd #implementation dependent
-do
-        #mark all user packets with their uid
-        iptables -A OUTPUT -t mangle -m owner --uid-owner $uid -j MARK --set-mark $uid
-        iptables -A OUTPUT -t mangle -m owner --uid-owner $uid -j CONNMARK --save-mark
-        #add rules to count packets
-        iptables -A PREROUTING -t mangle -m mark --mark $uid -m comment --comment "count $user"
-        iptables -A POSTROUTING -t mangle -m mark --mark $uid -m comment --comment "count $user"
-done
-</code>
-Integrating this with existing firewall rules is left as an excercise for the reader.
-Observing counters is as easy as
-<code bash>
-watch "iptables -nvL PREROUTING -t mangle; echo; iptables -nvL POSTROUTING -t mangle"
-</code>
-Or you can parse them periodically and store values somewhere for further processing.
-This method identifies which user caused some traffic only for the traffic that is initiated on the machine. Traffic that originates on a remote system is not caught. I haven't yet found a way to make this work for this case too.
-Tested on rhel6.