Cisco Nexus 1000V Layer 2 Switching Configuration Guide, Release 4.2(1)SV2(2.1)
Supporting Redundant Routing Protocols
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Supporting Redundant Routing Protocols

Supporting Redundant Routing Protocols

This chapter contains the following sections:

Information About Redundant Routing Protocols

The Cisco Nexus 1000V implements a loop detection mechanism that is based on source and destination MAC addresses and drops packets that are coming in on uplink ports if the source MAC address is already present on a local vEthernet interface. As a result, such protocols as the Virtual Router Redundancy Protocol (VRRP), the Common Address Redundancy Protocol (CARP), the Hot Standby Router Protocol (HSRP), and other similar protocols fail on Virtual Machines (VMs) that are associated to the Cisco Nexus 1000V.

Disabling loop detection provides a flexible way of supporting these protocols on VMs that are associated to the Cisco Nexus 1000V. By disabling the loop detection mechanism, you can configure any combination of the above mentioned protocols on a port profile or a vEthernet interface. As a result, you can run multiple protocols on the same VM.

Guidelines and Limitations

Supporting the redundant routing protocols feature has the following configuration guidelines and limitations:

  • Disable IGMP Snooping on both Cisco Nexus 1000V and upstream switches between the servers to support most redundant routing protocols. See Enabling or Disabling IGMP Snooping Globally for the VSM.
  • A disabled loop detection configuration is not supported on PVLAN ports.
  • A disabled loop detection configuration is not supported on the port security ports.

Supporting Redundant Routing Protocols

Configuring a vEthernet Interface to Support Redundant Routing Protocols

You can configure a vEthernet interface to support redundant routing protocols.

Before You Begin
  • Log in to the CLI in EXEC mode.
  • Know which redundant routing protocol that you want to disable.
Procedure
      Command or Action Purpose
    Step 1 switch# configure terminal 

    Enters global configuration mode.

     
    Step 2 switch(config)# interface vethernet interface-number 

    Enters interface configuration mode for the specified vEthernet interface (from 1 to 1048575).

     
    Step 3 switch(config-if)# disable-loop-detection {carp | hsrp | vrrp |custom-rp [src-mac-range s_mac end_mac] [dest-ip ip_address] [ip-proto no] [port port]} 

    Enables or disables the loop detection mechanism to support a redundant routing protocol on a vEthernet interface.

    • disable-loop-detection—Disables the loop detection mechanism.
    • no disable-loop-detection—Enables the loop detection mechanism. This is the default configuration.
    The protocols supported on a vEthernet interface are as follows:
    • carp—Common Address Redundancy Protocol
    • custom-rp—User-defined protocol
    • hsrp—Hot Standby Router Protocol
    • vrrp—Virtual Router Redundancy Protocol
    The parameters for custom defined protocols are as follows:
    • src-mac-range—Source MAC address range for the user-defined protocol.
    • dest-ip—Destination IP address for the user-defined protocol.
    • ip-proto—IP protocol number for the user-defined protocol.
    • port—UDP or TCP destination port number for the user-defined protocol.
     
    Step 4 switch(config-if)# show running-config interface vethernet interface-number  (Optional)

    Displays the interface status and information.

     
    Step 5 switch(config-if)# copy running-config startup-config  (Optional)

    Saves the change persistently through reboots and restarts by copying the running configuration to the startup configuration.

     

    This example shows how to configure a vEthernet interface to support VRRP, CERP, HSRP, and user-defined protocols on a VM:

    switch# configure terminal
    switch(config)# interface veth5
    switch(config-if)# disable-loop-detection carp
    switch(config-if)# disable-loop-detection vrrp
    switch(config-if)# disable-loop-detection hsrp
    switch(config-if)# disable-loop-detection custom-rp dest-ip 224.0.0.12 port 2234
    switch(config-if)# end
    switch# show running-config interface vethernet 5
    !Command: show running-config interface Vethernet5
    !Time: Fri Nov 4 02:21:24 2011
    
    version 4.2(1)SV1(5.1)
    
    interface Vethernet5
    inherit port-profile vm59
    description Fedora117, Network Adapter 2
    disable-loop-detection carp
    disable-loop-detection custom-rp dest-ip 224.0.0.12 port 2234
    disable-loop-detection hsrp
    disable-loop-detection vrrp
    vmware dvport 32 dvswitch uuid "ea 5c 3b 50 cd 00 9f 55-41 a3 2d 61 84 9e 0e c4"
    vmware vm mac 0050.56B3.00B2
    
    switch# 
    

    Configuring a Port Profile to Support Redundant Routing Protocols

    You can configure a port profile to support redundant routing protocols. Use this procedure when the master in a master/slave relationship has lost connectivity, the slave has taken over the master role, or the original master is attempting to overtake the master role.


    Note


    If you configure a vEthernet interface and a port profile to run multiple protocols on the same VM, the configuration on the vEthernet interface overrides the configuration on the port profile.


    Before You Begin
    • Log in to the CLI in EXEC mode.
    • Know which redundant routing protocol that you want to disable.
    Procedure
        Command or Action Purpose
      Step 1 switch# configure terminal 

      Enters global configuration mode.

       
      Step 2 switch(config)# port-profile name 

      Enters port profile configuration mode for the named port profile.

       
      Step 3 switch(config-port-prof)# switchport mode {access | trunk} 

      Designates that the interface is to be used as a trunking port.

      A trunk port transmits untagged packets for the native VLAN and transmits encapsulated, tagged packets for all other VLANs.

       
      Step 4 switch(config-port-prof)# no shutdown 

      Administratively enables all ports in the profile.

       
      Step 5 switch(config-port-prof)# disable-loop-detection {carp | hsrp | vrrp |custom-rp [src-mac-range s_mac end_mac] [dest-ip ip_address] [ip-proto no] [port port]} 

      Enables or disables the loop detection mechanism to support a redundant routing protocol on vEthernet interface.

      • disable-loop-detection—Disables the loop detection mechanism.
      • no disable-loop-detection—Enables the loop detection mechanism. This is the default configuration.
      The protocols supported on a vEthernet interface are as follows:
      • carp—Common Address Redundancy Protocol
      • custom-rp—User defined protocol
      • hsrp—Hot Standby Router Protocol
      • vrrp—Virtual Router Redundancy Protocol
      The parameters for custom defined protocols are as follows:
      • src-mac-range—Source MAC address range for the user defined protocol.
      • dest-ip—Destination IP address for the user defined protocol.
      • ip-proto—IP protocol number for the user defined protocol.
      • port—UDP or TCP destination port number for the user defined protocol.
       
      Step 6 switch(config-port-prof)# show port-profile [brief | expand-interface | usage] [name profile-name]  (Optional)

      Displays the configuration for verification.

       
      Step 7 switch(config-port-prof)# copy running-config startup-config  (Optional)

      Saves the change persistently through reboots and restarts by copying the running configuration to the startup configuration.

       

      This example shows how to disable loop detection for the Hot Standby Router Protocol:

      switch# configure terminal
      switch(config)# port-profile hsrp-1
      switch(config-port-prof)# switchport mode trunk
      switch(config-port-prof)# no shutdown
      switch(config-port-prof)# disable-loop-detection hsrp
      switch(config-port-prof)# state enabled
      switch(config-port-prof)# vmware port-group
      switch(config-port-prof)# show port-profile name hsrp-1
      port-profile hsrp-1
       type: Vethernet
       description:
       status: enabled
       max-ports: 32
       min-ports: 1
       inherit:
       config attributes:
        switchport mode trunk
        disable-loop-detection hsrp
        no shutdown
       evaluated config attributes:
        switchport mode trunk
        disable-loop-detection hsrp
        no shutdown
       assigned interfaces:
       port-group: hsrp-1
       system vlans: none
       capability l3control: no
       capability iscsi-multipath: no
       capability vxlan: no
       capability l3-vservice: no
       port-profile role: none
       port-binding: static
       
      

      This example shows how to disable loop detection for the Virtual Router Redundancy Protocol:

      n1000v# configure terminal
      switch(config)# port-profile vrrp-1
      switch(config-port-prof)# switchport mode trunk
      switch(config-port-prof)# no shutdown
      switch(config-port-prof)# disable-loop-detection vrrp
      switch(config-port-prof)# state enabled
      switch(config-port-prof)# vmware port-group
      switch(config-port-prof)# show port-profile name vrrp-1
      port-profile vrrp-1
       type: Vethernet
       description:
       status: enabled
       max-ports: 32
       min-ports: 1
       inherit:
       config attributes:
        switchport mode trunk
        disable-loop-detection vrrp
        no shutdown
       evaluated config attributes:
        switchport mode trunk
        disable-loop-detection vrrp
        no shutdown
       assigned interfaces:
       port-group: vrrp-1
       system vlans: none
       capability l3control: no
       capability iscsi-multipath: no
       capability vxlan: no
       capability l3-vservice: no
       port-profile role: none
       port-binding: static
      
      

      Feature History for Supporting Redundant Routing Protocol

      Feature Name

      Feature Name

      Releases

      Supporting Redundant Routing Protocol

      4.2(1)SV1(5.1)

      This feature was introduced.