updated manpage with TIME_WAIT recycling advice

diff --git a/pdns/docs/dnstcpbench.1.txt b/pdns/docs/dnstcpbench.1.txt
index 590b8521c775c825b97882682915b29908c90c58..a778d93658e697a009fe338da246d3e28fb93cfb 100644 (file)
--- a/pdns/docs/dnstcpbench.1.txt
+++ b/pdns/docs/dnstcpbench.1.txt
@@ -21,6 +21,12 @@ example:
        www.powerdns.com ANY\r
        powerdns.com MX\r
 \r
+When benchmarking extended runs, it may be necessary to enable TIME_WAIT\r
+recycling, as TCP/IP port tuples may otherwise run out.  On Linux this is\r
+performed by running:\r
+\r
+   # echo 1 > /proc/sys/net/ipv4/tcp_tw_recycle \r
+\r
 OPTIONS
 -------