`echo c > /proc/sysrq-trigger` fails when console speed is set to 9600 and iptables enabled

Issue

• When console speed is set to 9600 in grub.conf and iptables are enabled, echo c > /proc/sysrq-trigger run from ssh session triggers no crash kernel but iptables logs to console
• Issuing echo c > /proc/sysrq-trigger only generates iptabels output on console but no kdump is triggered while it works from console
• When changing console speed to 115200 baud it works also via ssh session
• In case iptables are disabled it also works with console speed set to 9600