Chapter 5. Networking

This chapter covers network optimization topics for virtualized environments.

5.1. Networking Tuning Tips

  • Use multiple networks to avoid congestion on a single network. For example, have dedicated networks for management, backups, or live migration.
  • Red Hat recommends not using multiple interfaces in the same network segment. However, if this is unavoidable, you can use arp_filter to prevent ARP Flux, an undesirable condition that can occur in both hosts and guests and is caused by the machine responding to ARP requests from more than one network interface: echo 1 > /proc/sys/net/ipv4/conf/all/arp_filter or edit /etc/sysctl.conf to make this setting persistent.

Note

For more information on ARP Flux, see http://linux-ip.net/html/ether-arp.html#ether-arp-flux