IOL (Serial)

Overview

Serial IOL nodes are a specialized implementation that supports serial interfaces. These serial interfaces support protocols like FrameRelay and HDLC / PPP. Other than the serial interface support, the serial IOL node definition and images provide a containerized Cisco IOS XE node, similar to the regular IOL nodes.

Limitations

The serial IOL nodes have a static 4-port Ethernet module installed. The rest of the interfaces on the IOL node are of type serial.

The serial IOL images do not support the programmability features that are available in other VM images based on IOS XE, like CSR 1000v. For example, the serial IOL images do not support restconf or netconf. You also cannot create EEM applets to add to the event manager on the device.

IOL's normal L1 signaling mechanism is disabled. Because of that, turning OFF an IOL interface has no effect. Turning the link OFF stops forwarding packets, but there's no "link loss". From the inside of the IOL node, the interface will still be shown as UP. This behavior matches that of other node types in CML, but it may be unexpected if you have used other IOL images in the past.

Using IOL (Serial) Nodes in CML

When you create links between two serial IOL nodes in the Workbench, CML allows you to connect serial ports of two IOL devices. The interface labels show the correct value as defined in the node definition like serial1/0.

Note: The Cisco VM images that are provided for download with Cisco Modeling Labs or as part of the CML refplat ISO file are only licensed for use within Cisco Modeling Labs. Downloading these VM images and using them outside Cisco Modeling Labs without a proper license is prohibited.

When capturing packets on a serial link, it is possible to select the expected frame encapsulation.

The PCAP display both in the CML UI's Packet Capture pane and in the resulting PCAP files have the proper link encapsulation set so that packets are displayed properly.