Neutron-automatic Network MTU

Neutron now supports the creation of different networks to specify different MTU, the scenario is primarily VLAN and Vxlan mixed.

Specific configuration

1. neutron.confnetwork_device_mtu=1450 # Devices in force: the namespace and NS interfaces of QDHCP and Qrouter network QR,QG and the corresponding Veth T on neutron networking nodes AP Device/usr/lib/python2.7/site-packages/neutron/agent/linux/interface.py If Self.conf.network_device_mtu:ns_dev . LINK.SET_MTU (SELF.CONF.NETWORK_DEVICE_MTU) if SELF.CONF.OVS_USE_VETH:ROOT_DEV.LINK.SET_MTU (sel F.CONF.NETWORK_DEVICE_MTU)

2, ML2_CONF.INIPATH_MTU = 9000SEGMENT_MTU = 1500

Flat how network types get mtu: /usr/lib/python2.7/site-packages/neutron/plugins/ml2/drivers/type_flat.pyclass  Flattypedriver (helpers. Basetypedriver):    #  Parent class basetypedriver     "" "Manage state  for flat networks with ML2.    The FlatTypeDriver  implements the  ' flat '  network_type. flat    network segments  provide connectivity between VMs and other    devices  Using any connected ieee 802.1d conformant    physical_network,  without the use of VLAN tags, tunneling, or     Other segmentation mechanisms. therefore at most one flat network     segment can exist on each available physical_network.      "" "    def __init__ (self):         Super (Flattypedriver, self). __init__ ()         self._parse_ Networks (CFG. CONF.ml2_type_flat.flat_networks)         #  if flat  is defined Provider Physet_mtus, take physical_network_mtus and segment_mtu the minimum value     def get_mtu (self,  physical_network):         seg_mtu = super ( flattypedriver, self). GET_MTU ()         mtu = []         if seg_mtu > 0:             mtu.append (SEG_MTU)          if physical_network in self.physnet_mtus:             mtu.append (int (self).Physnet_mtus[physical_network])         return min (MTU)  if  mtu else 0        /usr/lib/python2.7/site-packages/ Neutron/plugins/ml2/drivers/helpers.pyclass basetypedriver (API. Typedriver):     "" "Basetypedriver for functions common to segment  and flat. "" "     def __init__ (self):        try:             self.physnet_mtus = utils.parse_ Mappings (                cfg. conf.ml2.physical_network_mtus            )          except Exception:             self.physnet_mtuS = []    DEF GET_MTU (Self, physical_network=none):         return cfg. CONF.ml2.segment_mtu

VLAN network type How to obtain Mtu: class vlantypedriver (helpers. Segmenttypedriver):   #  Parent class segmenttypedriver     "" "Manage state  for VLAN networks with ML2.    The VlanTypeDriver  implements the  ' VLAN '  network_type. vlan    network segments  provide connectivity between VMs and other    devices  Using any connected ieee 802.1q conformant    physical_network  segmented into virtual networks via IEEE 802.1Q     Headers. up to 4094 vlan network segments can exist on each     available physical_network.     "" "    def  __init__ (self):         super (Vlantypedriver, self). __init__ (vlanallocation)         self._parse_network _vlan_ranges ()         # vlan gets the same MTU as flat      DEF GET_MTU (self, physical_network):         SEG_MTU  = super (vlantypedriver, self). GET_MTU ()         mtu  = []        if seg_mtu > 0:             mtu.append (SEG_MTU)          if physical_network in self.physnet_mtus:             mtu.append (int (self.physnet_mtus[physical_network))          return min (MTU)  if mtu else 0         /usr/lIb/python2.7/site-packages/neutron/plugins/ml2/drivers/helpers.pyclass basetypedriver (API. Typedriver):     "" "Basetypedriver for functions common to segment  and flat. "" "     def __init__ (self):        try:             self.physnet_mtus = utils.parse_ Mappings (                cfg. conf.ml2.physical_network_mtus            )          except Exception:             self.physnet_mtus = []    def get_mtu (Self,  physical_network=none):         return cfg. conf.ml2.segment_mtu  &Nbsp;     class segmenttypedriver (basetypedriver):     "" " segmenttypedriver for segment allocation.    provide methods  helping to perform segment allocation fully or partially     specified.     "" "    def __init__ (Self, model):         super (segmenttypedriver, self). __init__ ()          self.model = model         Self.primary_keys = set (Dict (model.__table__.columns))          self.primary_keys.remove ("allocated")

Vxlan How the network type gets Mtu:class vxlantypedriver (Type_tunnel. Endpointtunneltypedriver):   #  Parent class endpointtunneltypedriver    def  __init__ (self):         super (vxlantypedriver, self). __init__ (             vxlanallocation, vxlanendpoints)     def get_type (self):         return p_ Const. Type_vxlan    def initialize (self):         Try:            self._initialize (CFG. CONF.ml2_type_vxlan.vni_ranges)         except n_exc. Networktunnelrangeerror:            log.exception ( _le ("failed to parse vni_ranges. "                                 "service terminated!"))             raise systemexit ()                  def get_endpoints ( Self):         "" "Get every vxlan endpoints from  database. "" "         vxlan_endpoints = self._get_endpoints ()          return [{' IP_Address ': vxlan_endpoint.ip_address,                   ' Udp_port ':  vxlan_endpoint.udp_port,                   ' host ':  VXLAN_ENDPOINT.HOST} &NBsp;              for vxlan_ Endpoint in vxlan_endpoints]    def add_endpoint (Self, ip, host,  udp_port=p_const. Vxlan_udp_port):         return self._add_endpoint (Ip, host,  udp_port=udp_port)     def get_mtu (self, physical_network=none):         mtu = super (vxlantypedriver, self). GET_MTU ()          return mtu - p_const. Vxlan_encap_overhead if mtu else 0  # mtu - vxlan cost, auto minus VXLAN  overhead        from neutron.plugins.common import  constants as p_const/usr/lib/python2.7/site-packages/neutron/plugins/common/constants.py#  network type mtu overheadgenEve_encap_min_overhead = 50gre_encap_overhead = 42vxlan_encap_overhead = 50   # vxlan overhead Class endpointtunneltypedriver (tunneltypedriver): Class TunnelTypeDriver ( Helpers. Segmenttypedriver):     "" "define stable abstract interface for  ml2 type drivers.    tunnel type networks rely on  Tunnel endpoints. this class defines abstract    methods to  manage these endpoints.     "" "    def get_mtu ( Self, physical_network=none):         seg_mtu = super ( tunneltypedriver, self). GET_MTU ()         mtu = []         if seg_mtu > 0:          &nbSp;  mtu.append (SEG_MTU)         if cfg. conf.ml2.path_mtu > 0:             Mtu.append (CFG. CONF.ML2.PATH_MTU)         return min (MTU)  if mtu  Else 0

How the GRE network type gets Mtu:class gretypedriver (Type_tunnel. Endpointtunneltypedriver):    #  Parent class is also endpointtunneltypedriver     Def __init__ (self):         super (gretypedriver, self). __init __ (            greallocation, greendpoints)     def get_type (self):         return p_ Const. Type_gre    def initialize (self):         try:             self._initialize (CFG. CONF.ml2_type_gre.tunnel_id_ranges)         except n_exc. Networktunnelrangeerror:            log.exception ( _le ("failed to parse tunnel_id_ranges. "                                 "service terminated!"))             raise systemexit ()      def get_endpoints (self):         "" "Get every  gre endpoints from database. "" "         gre_endpoints = self._get_endpoints ()          return [{' IP_Address ': gre_endpoint.ip_address,                   ' host ':  gre_ endpoint.host}                 For gre_endpoint in gre_endpoints]    def add_endpoint (Self, ip,  host):  &NBsp;      return self._add_endpoint (ip, host)      DEF GET_MTU (self, physical_network=none):         mtu =  super (gretypedriver, self). GET_MTU (physical_network)          return mtu - p_const. Gre_encap_overhead if mtu else 0     # mtu - gre Overhead , Auto minus gre overhead        from neutron.plugins.common  import constants as p_const/usr/lib/python2.7/site-packages/neutron/plugins/common/constants.py # network type mtu overheadgeneve_encap_min_overhead = 50gre_encap_overhead  = 42    # gre overhead, why is 42, not yet clear vxlan_encap_overhead = 50   # vxlan overhead L version found neutron more kinds of network type Geneve,geneve introduction, temporarily do not know how to play http://blog.csdn.net/yeasy/article/details/39928153 

3, Neutron.confadvertise_mtu = true Previous practice: [[Email protected] ~ (Keystone_admin)]# cat  /etc/neutron/dnsmasq-neutron.conf  #  is effective for all network dhcp-option-force=26,1450     #  now we can get rid of this log-facility=/var/log/neutron/neutron-dnsmasq.log/usr/lib/python2.7/site-packages/. NEUTRON/AGENT/LINUX/DHCP.PYCLASS DNSMASQ (dhcplocalprocess):     # the ports  that need to be opened when security policies are active     # on the Neutron port used for DHCP.   These are provided as a convenience    # for users  of this class.        if cfg. conf.advertise_mtu:            mtu =  Self.network.mtu            # do not advertise unknown mtu             if mtu > 0:                 cmd.append ('--dhcp-option-force= option:mtu,%d '  % mtu)    #  see here         #  cap the limit because creating lots of subnets can inflate         # this possible lease cap.         cmd.append ('--dhcp-lease-max=%d '  %                    min (possible_leases,  Self.conf.dnsmasq_lease_max))         cmd.append ('--conf-file=%s '   % self.conf.dnsmasq_confiG_file)         if self.conf.dnsmasq_dns_servers:             cmd.extend (                  '--server=%s '  % server                 for server in  Self.conf.dnsmasq_dns_servers)

Reference links

Http://www.cnblogs.com/sammyliu/p/5079898.html

This article is from the "The-way-to-cloud" blog, make sure to keep this source http://iceyao.blog.51cto.com/9426658/1784871

Neutron-automatic Network MTU