search for: tcp_synack_retri

...//blog.dubbelboer.com/2012/04/09/syn-cookies.html Furthermore: "While you see SYN flood warnings in logs not being really flooded, your server is seriously misconfigured." *A potential fix* - increase the net.ipv4.tcp_max_syn_backlog kernel parameter. Or tune some more parameters like tcp_synack_retries and netdev_max_backlog *My question *- to fix this SYN flooding problem should I modify net.ipv4.tcp_max_syn_backlog, net.core.somaxconn and the backlog size passed to the listen() syscall or might there be an alternative easier fix such as installing 2.3.3-kh9<https://github.com/karlheyes/ic...

...net.ipv4.tcp_max_syn_backlog=2048 /sbin/sysctl -w net.ipv4.tcp_fin_timeout=30 /sbin/sysctl -w net.ipv4.tcp_keepalive_intvl=10 /sbin/sysctl -w net.ipv4.tcp_keepalive_probes=7 /sbin/sysctl -w net.ipv4.tcp_keepalive_time=1800 /sbin/sysctl -w net.ipv4.tcp_max_tw_buckets=360000 /sbin/sysctl -w net.ipv4.tcp_synack_retries=3 /sbin/sysctl -w net.ipv4.tcp_rmem="4096 87380 16777216" /sbin/sysctl -w net.ipv4.tcp_wmem="4096 87380 16777216" /sbin/sysctl -w net.ipv4.tcp_mem="8388608 8388608 8388608" --------------snip--------------- p.s. these are meant for a specific technology we use, so...

I get these errors from the following settings in /etc/sysctl.conf file: # Custom Settings: net.ipv4.tcp_max_syn_backlog=2048 net.ipv4.tcp_fin_timeout=30 net.ipv4.tcp_keepalive_intvl=10 net.ipv4.tcp_keepalive_probes=7 net.ipv4.tcp_keepalive_time=1800 net.ipv4.tcp_max_tw_buckets=360000 net.ipv4.tcp_synack_retries=3 net.ipv4.tcp_rmem="4096 87380 16777216" net.ipv4.tcp_wmem="4096 87380 16777216" net.ipv4.tcp_mem="8388608 8388608 8388608" ---------errors----------- # sysctl -p [errors] error: unknown error 22 setting key 'net.ipv4.tcp_rmem' error: unknown error 22 set...

Hello All, We have a Linux cluster application that uses openssh as its inter-node communication mechanism and we've recently run into a problem that points to a potential scalability issue in openssh code. Our client nodes systematically open ssh connections to the server node to execute an administrative command. When establishing socket connections, the server side sometimes fails to

Hello, I current have a FreeBSD 4.8 bridge firewall that sits between 7 servers and the internet. The servers are being attacked with syn floods and go down multiple times a day. The 7 servers belong to a client, who runs redhat. I am trying to find a way to do some kind of syn flood protection inside the firewall. Any suggestions would be greatly appreciated. -- Ryan James ryan@mac2.net

https://bugzilla.netfilter.org/cgi-bin/bugzilla/show_bug.cgi?id=40 laforge@netfilter.org changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |ASSIGNED ------- Additional Comments From laforge@netfilter.org 2003-02-03 16:49 ------- We haven't seen this