Netzwerk/ IP change (opensuse /SLES):
/etc/sysconfig/network/ifcfg-eth0
Temporary networking modification via ifconfig/ route:
ifconfig eth0 172.22.49.127 netmask 255.255.255.0 ifconfig eth0:0 192.168.0.5 netmask 255.255.255.0 #add temporary a 2nd ip-adress ifconfig eth0:1 192.168.0.6 netmask 255.255.255.0 #add temporary a 3nd ip-adress route add default gw 172.22.49.2 route del default gw 192.168.1.1 netmask 0.0.0.0 route add -host hostname.domain gw 192.168.1.1 route add -net 192.168.1.0 netmask 255.255.255.0 dev eth0 route add -net 192.168.30.0 netmask 255.255.255.0 gw 192.168.30.2 route add -host 192.168.0.1 dev ippp0 route del -host 192.168.0.1 route add default gw 192.168.0.1
ip a #show running interface(s) configuration ip addr add 10.0.2.15/24 dev enp0s3 #temporary set ip to interface "enp0s3" sudo ip link set enp0s3 down #interface "enp0s3" down sudo ip link set enp0s3 up #interface "enp0s3" up sudo ip route add default via 10.0.2.2 #temporary set default gateway
ip address show #like ifconfig ifconfig etho 192.168.63.73 netmask 255.255.255.0 ip addr list dev eth0 #list all IP´s for eth0 - also virtual ones!!
Example:
ip address add 192.168.63.73/24 brd + dev eth0
Config will be saved to:
/etc/sysconfig/network/ifcfg-eth0
BOOTPROTO='dhcp' #or static BROADCAST='' ETHTOOL_OPTIONS='' IPADDR='' #assigned if static e.g. 10.6.7.203 MTU='' NAME='AMD PCnet - Fast 79C971' NETMASK='' NETWORK='' REMOTE_IPADDR='' STARTMODE='auto' UNIQUE='rBUF.weGuQ9ywYPF' USERCONTROL='no' _nm_name='bus-pci-0000:02:01.0'
BOOTPROTO='static' BROADCAST='' ETHTOOL_OPTIONS='' IPADDR='10.6.7.203' MTU='' NAME='AMD PCnet - Fast 79C971' NETMASK='255.255.255.0' NETWORK='' REMOTE_IPADDR='' STARTMODE='auto' UNIQUE='rBUF.weGuQ9ywYPF' USERCONTROL='no' _nm_name='bus-pci-0000:02:01.0'
BOOTPROTO='dhcp' BROADCAST='' ETHTOOL_OPTIONS='' IPADDR='' MTU='' NAME='AMD PCnet - Fast 79C971' NETMASK='' NETWORK='' REMOTE_IPADDR='' STARTMODE='auto' UNIQUE='rBUF.weGuQ9ywYPF' USERCONTROL='no' _nm_name='bus-pci-0000:02:01.0' IPADDR_tomaddip='10.6.7.220' NETMASK_tomaddip='255.255.255.0' LABEL_tomaddip='tomaddip'
This file contains the network interfaces and their assigned MAC adresses
/etc/udev/rules.d/30-net_persistent_names.rules or /etc/udev/rules.d/70-persistent-net.rules
To change the default route permanently edit “/etc/sysconfig/network/routes” such as:
default 192.168.63.1 - -
Edit on command line the file /etc/sysconfig/network as follows:
NETWORKING=yes NETWORKING_IPV6=yes HOSTNAME=wan.nixcraft.in GATEWAY=74.86.49.129
Additionally edit /etc/sysconfig/network-scripts/ifcfg-eth0:
# Intel Corporation 82573E Gigabit Ethernet Controller (Copper) DEVICE="eth0" BOOTPROTO="static" HWADDR="00:30:48:56:A6:2E" NM_CONTROLLED="yes" ONBOOT="yes" TYPE="Ethernet" IPADDR=192.168.1.2 NETMASK=255.255.255.0
The following config (/etc/network/interfaces) shows a bonding interface (eth0, eth2) and a third networkdevice configuration (eth1):
# The loopback network interface
auto lo
iface lo inet loopback
# The primary network interface
auto bond0
iface bond0 inet static
address 192.168.64.127
netmask 255.255.255.0
network 192.168.64.0
broadcast 192.168.64.255
gateway 192.168.64.1
# dns-* options are implemented by the resolvconf package, if installed
dns-nameservers 192.168.63.4 192.168.63.8
dns-search my-domain.local
#slaves eth0 eth2
#bond_mode 0
#bond_miimon 100
#bond_updelay 200
#bond_downdelay 200
post-up ifenslave bond0 eth0 eth2
pre-down ifenslave -d bond0 eth0 eth2
#iSCSI Network Interface
auto eth1
iface eth1 inet static
address 192.168.254.55
netmask 255.255.254.0
network 192.168.254.0
broadcast 192.168.254.255
# gateway 192.168.254.1
# dns-* options are implemented by the resolvconf package, if installed
DHCP:
auto eth0 iface eth0 inet dhcp
ethtool eth0 #Show specifications of device "eth0" ethtool -t eth0 ethtool -i eth0
See also:
tcpdump -i eth0 tcpdump -niany tcpdump -i eth0 -s 65535 -w tracefile #Create dump, which can be imported in wireshark tcpdump -i eth0:0 -s 65535 -w tracefile.`date +%d.%m.%Y.%H.%M.%S` tcpdump -i eth1 -s 84 -w tracefile.`date +%d.%m.%Y.%H.%M.%S` #dump just header files tcpdump -i eth1 -qtln icmp
Start server:
(chmod +x iperf) ./iperf -s
Client:
iperf.exe -c 192.168.xxx.xxx -i5 -t 300 iperf3.exe -c 192.168.20.2 -i5 -t300
Telnet is a very good tool to test open ports.
telnet localhost 25 telnet IP 25 telnet 192.168.0.20 25 echo quit | telnet 192.168.1.1 22 | grep –i connected
If there´s no telnet:
nc -zv 192.168.0.20 25
or:
lsof -Pi :8443 #just local test
or:
echo >/dev/tcp/localhost/25 echo >/dev/tcp/192.168.0.20/25
ehlo testmail.org (Identify and demand SMTP-Modus) mail from:<test@testmail.org> (Sender) rcpt to:<roehm@linux.de> (Receiver) data (Enable to write an EMail) . (Terminate insert-Mode) quit (Terminate session)
Tip:
reset (enables to send additionally emails)
curl -v -H "Host: my-server.mydomain.com" 127.0.0.1:8443 #test connectivity locally on host to simulate external access curl -X GET https://my-domain.de:6443 #check if port is open curl --noproxy "*" http://localhost:8080 #check if port is open
NLB #Network Load Balancing LACP #Link Aggregation Control Protocol (LACP) STACKING #Join logical switches over a special connection (high speed) to one switch with more ports