ifup part in RHEL5.5

# Ethernet 802.1Q VLAN support
if [ -x /sbin/vconfig -a "${VLAN}" = "yes" -a "$ISALIAS" = "no" ]; then
    VID=""
    MATCH='^(eth|hsi|bond)[0-9]+\.[0-9]{1,4}$'
    if [[ "${DEVICE}" =~ $MATCH ]]; then
        VID=$(echo "${DEVICE}" | LC_ALL=C sed 's/^[a-z0-9]*\.0*//')
        PHYSDEV=${DEVICE%.*}
    fi
    if [[ "${DEVICE}" =~ '^vlan[0-9]{1,4}?' ]]; then
        VID=$(echo "${DEVICE}" | LC_ALL=C sed 's/^vlan0*//')
        # PHYSDEV should be set in ifcfg-vlan* file
        if test -z "$PHYSDEV"; then
                echo $"PHYSDEV should be set for device ${DEVICE}"
                exit 1
        fi
    fi
    if [ -n "$VID" ]; then
        if [ ! -d /proc/net/vlan ]; then
            if ! modprobe 8021q >/dev/null 2>&1 ; then
                echo $"No 802.1Q VLAN support available in kernel for device ${DEVICE}"
                exit 1
            fi
        fi
        test -z "$VLAN_NAME_TYPE" && VLAN_NAME_TYPE=DEV_PLUS_VID_NO_PAD
        /sbin/vconfig set_name_type "$VLAN_NAME_TYPE" >/dev/null 2>&1 || {
                echo $"Could not set 802.1Q VLAN parameters."
        }

        is_available ${PHYSDEV} || {
            if [ "$?" = "1" ] ; then
                echo $"$alias device ${DEVICE} does not seem to be present, delaying initialization."
                exit 1
            else
                exit 0
            fi
        }

        # Link on Physical device needs to be up but no ip required
        check_device_down ${PHYSDEV} && {
            ip -o link set dev ${PHYSDEV} up
        }

        if [ ! -f /proc/net/vlan/${DEVICE} ]; then
            /sbin/vconfig add ${PHYSDEV} ${VID} || {
                (/usr/bin/logger -p daemon.info -t ifup \
                    $"ERROR: could not add vlan ${VID} as ${DEVICE} on dev ${PHYSDEV}" &)&
                echo $"ERROR: could not add vlan ${VID} as ${DEVICE} on dev ${PHYSDEV}"
                exit 1
            }
        fi

        if [ -f /proc/net/vlan/${DEVICE} ]; then
            case "$REORDER_HDR" in
                yes|1)
                    /sbin/vconfig set_flag ${DEVICE} 1 1 || {
                        (/usr/bin/logger -p daemon.info -t ifup \
                            "WARNING: vconfig not able to enable REORDER_HDR on ${DEVICE}" &)&
                    }
                    ;;
                no|0)
                    /sbin/vconfig set_flag ${DEVICE} 1 0 || {
                        (/usr/bin/logger -p daemon.info -t ifup \
                            $"WARNING: vconfig not able to disable REORDER_HDR on ${DEVICE}" &)&
                    }
                    ;;
            esac
        fi
    fi
fi