Unlike the commercial XRv, this demo image has reduced forwarding performance. Do not use for throughput testing >100 Mbps.
A full ASR9k virtual image might require 16GB of RAM and 4 vCPUs just to boot. The demo image is optimized for:
In the world of computer networking, there are few file extensions that spark as much excitement—and frustration—as .qcow2. It stands for QEMU Copy On Write version 2, and it represents a virtual hard drive. But the filename Iosxrv-k9-demo-6.1.3.qcow2 isn't just a random string of characters. It is a time capsule. It is a training ground. For many network engineers, it was their first glimpse into the future of Service Provider networking.
Let’s pop the hood on this specific file and explore why this particular version of Cisco’s IOS XRv remains a fascinating artifact in the history of network engineering.
This file is a disk image (hard drive) for a virtual router, not an ISO installer.
Cisco IOS XR is significantly different from standard IOS or IOS XE. It is a micro-kernel architecture designed for high-end Carrier Grade Routers (like the CRS-1, ASR 9000, and NCS 5500).
IOS XRv 6.1.3 sits at a sweet spot in history:
Problem: "Kernel panic - not syncing: VFS: Unable to mount root fs"
Solution: Ensure if=virtio is set. IOS XRv 6.1.3 expects a VirtIO block device.
Problem: Console shows "No license found. Router will reload in 360 minutes."
Solution: The demo timer is active. Commit license smart register or set the system clock back (not recommended) via clock set.
Problem: SSH fails after port forward.
Solution: Verify SSH is enabled. Default XR config requires:
Router(config)# ssh server vrf default
Router(config)# commit
qemu-system-x86_64 -nographic -machine accel=kvm \
-m 4096 -smp 2 -cpu host \
-drive file=iosxrv-k9-demo-6.1.3.qcow2,if=virtio,format=qcow2 \
-netdev tap,id=net0,ifname=tap0,script=no,downscript=no \
-device virtio-net-pci,netdev=net0 \
-serial mon:stdio