Configuring OSPF on a VLAN

Configure OSPF parameters on a VLAN to control OSPF behavior on the VLAN.

Important

Important

When you enable OSPF on a VLAN, the switch automatically creates an area 0.0.0.0, and advertises it on the specific VLAN, by default. To avoid this behavior, you must manually configure the VLAN into a properly configured area on the switch.

Before you begin

  • Enable OSPF globally.

  • Ensure that the VLAN uses an IP address.

  • Ensure that the ospf_md5key.txt file is on the switch to use MD5 authentication.

  • Ensure that you know the network OSPF to use password authentication.

  • Change the VRF instance as required to configure OSPF on a specific VRF instance. The VRF must have an RP trigger of OSPF. Not all parameters are configurable on non-default VRFs.

Procedure

  1. In the navigation pane, expand Configuration > VLAN.
  2. Click VLANs.
  3. Click the Basic tab.
  4. Select a VLAN.
  5. Click IP.
  6. Click the OSPF tab.

    The information on the OSPF tab applies only to a routed port or VLAN, which means the VLAN uses an IP address.

  7. To enable OSPF on the VLAN interface, select the Enable check box.
  8. To change their values, select the current value in the HelloInterval, RtrDeadInterval, or PollInterval boxes, and then type new values.
  9. To designate a router priority, in the DesigRtrPriority box, type the new value.
  10. Select the authentication type in the AuthType field.
  11. If you chose simplePassword, in the AuthKey box, type a password of up to eight characters.
  12. Select the interface type you want to create.
  13. Click Apply.

OSPF Field Descriptions

Use the data in the following table to use the OSPF tab.

Name

Description

Enable

Enables or disables OSPF routing on the specified VLAN. The default is false.

HelloInterval

Specifies the length of time, in seconds, between the transmission of hello packets. This value must be the same for all routers attached to a common network. The default is 10 seconds.

After you change the hello interval values, you must save the configuration file, and then restart the switch. After the switch restarts, it restores the values and checks for consistency.

RtrDeadInterval

Specifies the interval used by adjacent routers to determine if the router was removed from the network. This interval must be identical on all routers on the subnet and a minimum of four times the hello interval. To avoid interoperability issues, the RtrDeadInterval value for the OSPF interface needs to match with the RtrDeadInterval value for the OSPF virtual interface. The default is 40 seconds.

DesigRtrPriority

Specifies the priority of this VLAN in multiaccess networks to use in the designated router election algorithm. The value 0 indicates the router is not eligible to become the designated router on this particular network. If a tie occurs, routers use their router ID as a tie breaker. The default is 1.

Metric

Specifies the metric for this TOS on this VLAN. The value of the TOS metric is (10^9 / interface speed). The default is 1.

  • FFFF—No route exists for this TOS.

  • IPCP links—Defaults to 0.

  • 0—Use the interface speed as the metric value when the state of the interface is up.

AuthType

Specifies the type of authentication required for the interface.

  • none—Specifies that no authentication required.

  • simple password—Specifies that all OSPF updates received by the interface must contain the authentication key specified in the interface AuthKey parameter.

  • MD5 authentication—Specifies that all OSPF updates received by the interface must contain the MD5 key.

  • sha1—Specifies secure hash algorithm 1 (SHA-1), which is a cryptographic hash function that produces a 160-bit hash value, usually given in a hexadecimal number, 40 digits long. You can only access and enable the SHA-1 authentication type after you enable enhanced secure mode.

  • sha-2—Specifies SHA-2, which offers the hash function SHA-256.

    Note:

    sha-2, an update of SHA-1, can offer six hash functions that include SHA-224, SHA-256, SHA-384, SHA-512, SHA-512/224, SHA 512/256, with hash values that are 224, 256, 384, or 512 bits. However, the current release supports only SHA-256.

AuthKey

Specifies the key (up to eight characters) when you specify simple password authentication in the VLAN AuthType variable.

AreaId

Specifies the OSPF area name in dotted-decimal format.

The area name is not related to an IP address. You can use a suitable value for the OSPF area name (for example, 1.1.1.1 or 200.200.200.200).

AdvertiseWhenDown

Advertises the network even if the port is down. If true, OSPF advertises the network on this VLAN as up, even if the port is down. The default is false.

After you configure a port without a link and enable AdvertiseWhenDown, it does not advertise the route until the port is active. Then, OSPF advertises the route even when the link is down. To disable advertising based on link states, disable AdvertiseWhenDown.

IfType

Specifies the type of OSPF interface (broadcast, NBMA, or passive).

Before you change an OSPF interface type, you must first disable the interface. If the interface is an NBMA interface, you must also delete all configured neighbors.

PollInterval

Specifies the length of time, in seconds, between hello packets sent to an inactive OSPF router. Neighbors must use the same poll interval.

IfMtuIgnore

Specifies whether the VLAN ignores the MTU configuration. To allow the switch to accept OSPF DD packets with a different MTU size, enable MtuIgnore. The interface drops incoming OSPF DD packets if their MTU is greater than 1500 bytes.

BfdEnable

Enables Bidirectional Forwarding Detection (BFD) for OSPF.
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