Настроить сеть на хосте KVM

bridge name	bridge id		STP enabled	interfaces
virbr0		8000.525400c2e4d1	yes		virbr0-nic
							vnet0

# You don't usually need to touch this file at all, the full configuration
# of the bridge can be done in a standard way on /etc/network/interfaces.

# Have a look at /usr/share/doc/bridge-utils/README.Debian if you want
# more info about the way on wich a bridge is set up on Debian.

if [ ! -x /sbin/brctl ]
then
  exit 0
fi

. /lib/bridge-utils/bridge-utils.sh

case "$IF_BRIDGE_PORTS" in
    "")
	exit 0
	;;
    none)
	INTERFACES=""
	;;
    *)
	INTERFACES="$IF_BRIDGE_PORTS"
	;;
esac

# Previous work (create the interface)
if [ "$MODE" = "start" ] && [ ! -d /sys/class/net/$IFACE ]; then
  brctl addbr $IFACE || exit 1
  if [ "$IF_BRIDGE_HW" ]; then
    ip link set dev $IFACE address $IF_BRIDGE_HW
  fi
# Wait for the ports to become available
  if [ "$IF_BRIDGE_WAITPORT" ]
  then
    set x $IF_BRIDGE_WAITPORT &&   
    shift &&
    WAIT="$1" &&
    shift &&
    WAITPORT="$@" &&
    if [ -z "$WAITPORT" ];then WAITPORT="$IF_BRIDGE_PORTS";fi &&
    STARTTIME=$(date +%s) &&
    NOTFOUND="true" &&
    /bin/echo -e "\nWaiting for a max of $WAIT seconds for $WAITPORT to become available." &&
    while [ "$(($(date +%s)-$STARTTIME))" -le "$WAIT" ] && [ -n "$NOTFOUND" ]
    do
      NOTFOUND=""
      for i in $WAITPORT
      do
        if ! grep -q "^[\ ]*$i:.*$" /proc/net/dev;then NOTFOUND="true";fi
      done
      if [ -n "$NOTFOUND" ];then sleep 1;fi
    done
  fi
# Previous work (stop the interface)
elif [ "$MODE" = "stop" ];  then
  ip link set dev $IFACE down || exit 1
fi

all_interfaces= &&
unset all_interfaces &&
bridge_parse_ports $INTERFACES | while read i
do
  for port in $i
  do
    # We attach and configure each port of the bridge
    if [ "$MODE" = "start" ] && [ ! -d /sys/class/net/$IFACE/brif/$port ]; then
      if [ -x /etc/network/if-pre-up.d/vlan ]; then
        env IFACE=$port /etc/network/if-pre-up.d/vlan
      fi
      if [ "$IF_BRIDGE_HW" ]
      then
        KVER="$(uname -r)"
        LKVER="${KVER#*.}"
        LKVER="${LKVER%%-*}"
        LKVER="${LKVER%%.*}"
        if [ "${KVER%%.*}" -lt 3 -o "${KVER%%.*}" -eq 3 -a "$LKVER" -lt 3 ]
        then
          ip link set dev $port address $IF_BRIDGE_HW
        fi
      fi
      if [ -f /proc/sys/net/ipv6/conf/$port/disable_ipv6 ]
      then
        echo 1 > /proc/sys/net/ipv6/conf/$port/disable_ipv6
      fi
      brctl addif $IFACE $port && ip link set dev $port up
    # We detach each port of the bridge
    elif [ "$MODE" = "stop" ] && [ -d /sys/class/net/$IFACE/brif/$port ];  then
      ip link set dev $port down && brctl delif $IFACE $port && \
        if [ -x /etc/network/if-post-down.d/vlan ]; then
          env IFACE=$port /etc/network/if-post-down.d/vlan
        fi
      if [ -f /proc/sys/net/ipv6/conf/$port/disable_ipv6 ]
      then
        echo 0 > /proc/sys/net/ipv6/conf/$port/disable_ipv6
      fi
    fi
  done
done

# We finish setting up the bridge
if [ "$MODE" = "start" ] ; then

  if [ "$IF_BRIDGE_AGEING" ]
  then
    brctl setageing $IFACE $IF_BRIDGE_AGEING
  fi

  if [ "$IF_BRIDGE_BRIDGEPRIO" ]
  then
    brctl setbridgeprio $IFACE $IF_BRIDGE_BRIDGEPRIO
  fi

  if [ "$IF_BRIDGE_GCINT" ]
  then
    brctl setgcint $IFACE $IF_BRIDGE_GCINT
  fi

  if [ "$IF_BRIDGE_HELLO" ]
  then
    brctl sethello $IFACE $IF_BRIDGE_HELLO
  fi

  if [ "$IF_BRIDGE_MAXAGE" ]
  then
    brctl setmaxage $IFACE $IF_BRIDGE_MAXAGE
  fi

  if [ "$IF_BRIDGE_PATHCOST" ]
  then
    brctl setpathcost $IFACE $IF_BRIDGE_PATHCOST
  fi

  if [ "$IF_BRIDGE_PORTPRIO" ]
  then
    brctl setportprio $IFACE $IF_BRIDGE_PORTPRIO
  fi

  if [ "$IF_BRIDGE_STP" ]
  then
    brctl stp $IFACE $IF_BRIDGE_STP
  fi

  if [ "$IF_BRIDGE_FD" ]
  then
    brctl setfd $IFACE $IF_BRIDGE_FD
  fi


  # We activate the bridge
  ip link set dev $IFACE up


  # Calculate the maximum time to wait for the bridge to be ready
  if [ "$IF_BRIDGE_MAXWAIT" ]
  then
    MAXWAIT=$IF_BRIDGE_MAXWAIT
  else
    MAXWAIT=$(brctl showstp $IFACE 2>/dev/null|sed -n 's/^.*forward delay[ \t]*\(.*\)\..*bridge forward delay[ \t]*\(.*\)\..*$/\1 \2/p')
    if [ "$MAXWAIT" ]
    then
      if [ ${MAXWAIT% *} -gt ${MAXWAIT#* } ]
      then
        MAXWAIT=$((2*(${MAXWAIT% *}+1)))
      else
        MAXWAIT=$((2*(${MAXWAIT#* }+1)))
      fi
    else
      if [ "$IF_BRIDGE_FD" ]
      then
        MAXWAIT=$((2*(${IF_BRIDGE_FD%.*}+1)))
      else
        MAXWAIT=32
      fi
      /bin/echo -e "\nWaiting $MAXWAIT seconds for $IFACE to get ready."
      sleep $MAXWAIT
      MAXWAIT=0
    fi
  fi


  # Wait for the bridge to be ready
  if [ "$MAXWAIT" != 0 ]
  then
    /bin/echo -e "\nWaiting for $IFACE to get ready (MAXWAIT is $MAXWAIT seconds)."

    unset BREADY
    unset TRANSITIONED
    COUNT=0

    # Use 0.1 delay if available
    sleep 0.1 2>/dev/null && MAXWAIT=$((MAXWAIT * 10))

    while [ ! "$BREADY" -a $COUNT -lt $MAXWAIT ]
    do
      sleep 0.1 2>/dev/null || sleep 1
      COUNT=$(($COUNT+1))
      BREADY=true
      for i in $(brctl showstp $IFACE|sed -n 's/^.*port id.*state[ \t]*\(.*\)$/\1/p')
      do
        if [ "$i" = "listening" -o "$i" = "learning" -o "$i" = "forwarding" -o "$i" = "blocking" ]
        then
          TRANSITIONED=true
        fi
        if [ "$i" != "forwarding" -a "$i" != "blocking" ] && [ ! "$TRANSITIONED" -o "$i" != "disabled" ]
        then
          unset BREADY
        fi
      done
    done

  fi

# Finally we destroy the interface
elif [ "$MODE" = "stop" ];  then

  brctl delbr $IFACE

fi

    <interface type='bridge'>
      <mac address='52:54:00:dd:f0:72'/>
      <source bridge='virbr0'/>
      <target dev='vnet0'/>
      <model type='rtl8139'/>
      <alias name='net0'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
    </interface>

<network>
  <name>default</name>
  <uuid>d0e58956-e98f-4326-87cf-ecdc85be2dc1</uuid>
  <forward mode='nat'>
    <nat>
      <port start='1024' end='65535'/>
    </nat>
  </forward>
  <bridge name='virbr0' stp='on' delay='0'/>
  <mac address='52:54:00:c2:e4:d1'/>
  <ip address='192.168.122.1' netmask='255.255.255.0'>
    <dhcp>
      <range start='192.168.122.2' end='192.168.122.254'/>
    </dhcp>
  </ip>
</network>