network

Meassure connection time with curl

Get response time with curl:

Total time

curl -o /dev/null -s -w 'Total: %{time_total}s\n' https://www.google.com

Establish connection/time to first byte/total time

Check your IPv6 subnet with
subnetcalc ipv6_ip_address

For a dig with dns request flow response use

dig hostname.tld +trace

In order to pest whether is network port accessible, either udp or tcp.

Can server listen on udp port 5000 ?

Example with UDP port!

Server side
ncat -ulp 5000

Client side
ncat -u XXX.XXX.XXX.XXX 5000

Add IP address to whitlist with fail2ban
Open config file

vim /etc/fail2ban/jail.conf

find a line
ingoreip =
add particular IP or subnet
Remember to keep a space between records

Show transceiver type on Arista switches

show inventory
show interfaces status

If you need to create manually network interface in centos6

Get to network interface folder
cd /etc/sysconfig/network-scripts/

copy one of current to create a new one
cp ifcfg-eth0 ifcfg-ethX

Chek for crc error on network interface
ethtool -S "interface" |grep crc
netstat -i
ip -s link show
ip rule list
ip -c r get 64.225.97.21

Bond test
Switchnig between slaves

ifenslave -c bond0 ethX

Bond status
cat /proc/net/bonding/bond0

To set LACP bonding correctly add file
vim /etc/modprobe.d/bonding.conf
options bonding mode=4 xmit_hash_policy=1

Po vymene IP na bondu v Archlinuxu
modprobe -r bonding
nmctl start bond0