IMA bundles

Use the following CLI syntax to configure IMA bundle parameters:

configure# port bundle-type-slot/mda.bundle-num
    — description description-string
    — multilink-bundle
        — fragment-threshold value
        — ima
            — atm
                — cell-format {uni | nni}
                — min-vp-vpi vp-vpi-value
            — exit
            — link-delay {activate |deactivate} milli-seconds
            — max-bandwidth number-links
            — version ima-version
        — red-differential-delay red-diff-delay down
        — member port-id

Configuration notes:

An IMA group has common interface characteristics (for example, configuration that applies to a logical ATM interface either configured via the IMA group context or taken from the primary link) The following list details those common IMA group interface characteristics:

Member links inherit those common characteristics from the IMA group that they are part of and as long as they are part of an IMA group. Characteristics derived from the primary link (MTU, interface mode type) can be changed on the primary link only and not on other links in the bundle or a bundle itself. The primary link is the member which has the lowest ifindex. When a member is added/deleted, the primary member may be changed based on the ifIndicies of all member links.

After a path becomes part of an IMA group logical link, the path ceases to exist as a physical ATM path interface. This means that:

  1. ATM interface bundle characteristics enforced over the link. Note that when a link is removed from an IMA bundle, the link's ATM characteristics are reset to ATM interface defaults.

  2. No services can be configured on the member link itself.

After the primary member has been added each additional member added to the group is only accepted if it matches the configuration of the IMA group. ATM interface characteristics are not part of this verification as they are overwritten/reset to defaults when a link is added to/removed from an IMA bundle.

Upon addition to an IMA group, each added member is automatically assigned an IMA link ID. IMA link IDs are in range from 0 to 7 and stay constant as long as the router does not reboot.

When configuring IMA bundles, consider the following guidelines:

The following example shows the creation of an IMA bundle with three group members residing on a channelized OC-3 ASAP MDA in slot 5/2/1:

A:ALA-A>config# port bundle-ima-5/2.1
A:ALA-A>config>port# multilink-bundle
A:ALA-A>config>port>ml-bundle# member 5/2/1.1.1.1
A:ALA-A>config>port>ml-bundle# member 5/2/1.1.2.1

A:ALA-A>config>port>ml-bundle# member 5/2/1.1.3.1