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kvm:bridge_interface [2021/04/09 10:23]
admin
kvm:bridge_interface [2021/04/09 10:40] (current)
admin
Line 102: Line 102:
 </​code>​ </​code>​
  
 +<note warning>​In this configuration second interface eth1 and br2 will not be accessible outside.</​note>​
 +
 +<note important>​To use a second interface and address we need to add another routing table.To do this go to file:</​note>​
 +
 +<code bash>
 +# vim /​etc/​iproute2/​rt_tables
 +</​code>​
 +and add at the end “1 rt2”:
 +
 +<code winbatch>​
 +#
 +# reserved values
 +#
 +255     local
 +254     main
 +253     ​default
 +0       ​unspec
 +#
 +# local
 +#
 +#1      inr.ruhep
 +1 rt2
 +</​code>​
 +
 +Now we need to add routing rules and routes:
 +
 +<code bash>
 +ip route add default via 10.5.23.254 dev br2 table rt2;
 +ip rule add from 10.5.23.0/​24 table rt2
 +</​code>​
 +
 +You can check these changes with commands:
 +
 +<code bash>
 +# ip route show table rt2
 +# ip rule show
 +</​code>​
 +
 +==== CentOS: Start custom script automatically after network startup ====
 +
 +Find the ifup-post under /​etc/​sysconfig/​network-scripts. This scipt is called right after any network interface is brought up online. In this script, you will find the following code snippet toward the end.
 +<code bash>
 +
 +if [ -x /​sbin/​ifup-local ]; then
 +    /​sbin/​ifup-local ${DEVICE}
 +</​code>​
 +
 +In the code snippet above, if ifup-local script exists in /sbin location, then script gets executed with an interface name in argument. Usually no such ecript like ifup-local exists so in order to run a startup script automatically after a network interface is up. Create an executable script called ifup-local in /sbin and put in there any command or script you wish to run.
 +
 +Here is an example:
 +
 +<code bash>
 +if [[ "​$1"​ == "​eth0"​ ]]
 +then
 +  echo "this part will be executed right after eth0 is up."
 +  echo "so you can put any startup command for eth0 here"
 +else
 +  #DO_NOTHING
 +fi
 +</​code>​
 +
 +when script is done, use command to get the script executable.
 +
 +<code bash>
 +$ sudo chmod +x /​sbin/​ifup-local
 +</​code>​
  
-<note important>​If you want to after reboot or restart network service save bridge configuration</​note>​ 
  
 <code bash> <code bash>
kvm/bridge_interface.1617956601.txt.gz · Last modified: 2021/04/09 10:23 by admin