5.7 Monitoring the ISDN Interface
5.7.3 Verifying PPP multilink
The Figure shows an output of the show ppp multilink command. It displays bundle information on a rotary group in the packet multiplexing section, including the number of members in a bundle and the bundle to which a link belongs. (Note: A rotary group allows you to create a single interface configuration and bind it to a group of physical interfaces.)

Note: Click on the topology to view the command outputs.

The show interface command also displays information on the status of multilink. As shown by the bolded portion of the screen output in the example, only the B1 channel has its Link Control Protocol (LCP) up. Also, the B1 channel shows the Network Control Protocol (NCP) as being open, whereas the B2 channel shows the NCP as being closed because the second link has not come up yet.

In the previous screen output, you can see that B1 is up, but B2 is still down. Also notice that the LCP list Multilink is opened for B1. The multilink open state appears after the interface is configured for MLP, regardless of whether other links have joined the bundle.