Network Performance

This command will show if packets are being dropped and the q needs to be lenghtened
#tc -s qdisc show dev eth0

Network statistics
#netstat -a

Check reassembly failures, this will indicate a buffer change is required
#cat /proc/net/snmp | grep "^Ip:" | cut -f17 -d" "

BDP
Use Ping to determine round trip time
#ping remotehost
PING remotehost (192.168.48.190) 56(84) bytes of data.
64 bytes from ex442-2 (192.168.48.190): icmp_seq=1 ttl=64 time=1.65 ms

Check the bandwidth using ethtool
#ethtool eth0

BDP = Bandwidth * Delay

BDP = (100Mbps * 1024 *1024 / 8 ) * 1.65 =  21626880

Copy the old settings to sysctl.conf and comment out
#sysctl -a | grep rmem >> /etc/sysctl.conf

edit with
net.ipv4.tcp_rmem = 21626880     21626880     21626880
net.core.rmem_default = 21626880    
then
#sysctl -p