# ArubaCX VXLAN Routing Packets Have Invalid Lengths

DevFeed: [ArubaCX VXLAN Routing Packets Have Invalid Lengths](<https://devfeed.tech/articles/arubacx-cannot-count-when-dealing-with-vxlan-11193.md>)

Original publisher: [Read original article](<https://blog.ipspace.net/2025/06/aruba-vxlan-packet-length/>)

Published: 2025-06-12T05:08:00Z

Content type: tutorial

Language: en

Sources: [ipSpace.net blog](<https://devfeed.tech/sources/ipspace-net-blog.md>)

Topics: [VXLAN](<https://devfeed.tech/topics/vxlan.md>), [networking](<https://devfeed.tech/topics/networking.md>), [Linux](<https://devfeed.tech/topics/linux.md>), [virtual machines](<https://devfeed.tech/topics/virtual-machines.md>)

Tags: [capture](<https://devfeed.tech/tags/capture.md>), [ethernet](<https://devfeed.tech/tags/ethernet.md>), [linux](<https://devfeed.tech/tags/linux.md>), [netlab](<https://devfeed.tech/tags/netlab.md>), [tailscale](<https://devfeed.tech/tags/tailscale.md>), [virtual-machines](<https://devfeed.tech/tags/virtual-machines.md>), [vxlan](<https://devfeed.tech/tags/vxlan.md>)

## AI overview

A netlab IRB test exposed that VXLAN packets generated by ArubaCX's routing process reported IP and UDP lengths four bytes larger than the actual packet. The article uses packet captures to trace the issue to a VLAN tag removed during software VXLAN encapsulation without a corresponding length adjustment.

## Source excerpt

This blog post describes yet another bizarre example of how reliable digital twins are, but don't worry; they all work great in PowerPoint. After "fixing" the integration tests to deal with ArubaCX's notion of VXLAN VNI having 16 bits, the bridging test worked, but the IRB tests kept failing. In the IRB test, the lab has two layer-3 switches. Each of them should be able to bridge within a VLAN/VXLAN segment and route across the segments. Read more ...