Encountering the dreaded “connection error. can’t fetch server config.” message on your Meraki devices can be a significant roadblock for network administrators. This issue prevents devices from updating their configurations from the Meraki cloud, essentially taking them offline and disrupting network operations. Based on insider information and practical experience, let’s delve into the potential causes and, more importantly, the solutions to this frustrating problem.
According to off-the-record sources, the root of many “unable to fetch config” errors lies within the Meraki MX appliance’s file system. It appears that the file system responsible for storing the device configuration, separate from the OS file system, can sometimes unmount. While the exact reasons for this dismounting remain undisclosed, the consequence is clear: the MX device loses its ability to synchronize its configuration with the Meraki cloud. This desynchronization triggers the “Unable to Fetch Config” error, as the device can no longer retrieve the necessary settings.
Meraki support engineers often employ backend interventions to temporarily resolve this issue. These actions typically involve remounting the affected file system, which effectively brings the MX device back online. However, this remounting is often a temporary fix, not a permanent solution, as the underlying cause of the file system dismounting isn’t addressed.
The good news is that firmware version 15.4X appears to offer a robust solution to this persistent problem. Anecdotal evidence strongly suggests that upgrading to version 15.4X can significantly reduce, if not eliminate, “unable to fetch config” errors. One user reported experiencing five instances of this error in quick succession before upgrading 145 MX64 devices to firmware 15.40. Since the upgrade, spanning over two months, no further “unable to fetch config” issues have been observed on these devices. Meraki support has indicated that the file system issue is prevalent in all 14.XX firmware revisions and is specifically addressed and resolved in the 15.XX branch.
While firmware 15.40 and 15.42 are reported to be equally effective in resolving the configuration fetching issue, it’s worth noting a potential caveat related to Client VPN and PCI compliance. Version 15.4X may introduce a compatibility issue with certain PCI compliance scans, specifically those from Trustwave, concerning Diffie-Hellman group and Cipher configurations within Client VPN setups. A backend fix is reportedly required to address this, and it may not be fully functional in version 15.4X at the time of writing. This means that while Client VPN functionality remains operational, organizations requiring PCI compliance and utilizing Client VPN might encounter scan failures after upgrading to 15.4X. This issue primarily affects users needing both Client VPN and PCI compliance who update to 15.42.
On a positive note, site-to-site VPN connections on Meraki devices remain unaffected by the “unable to fetch config” issue and firmware 15.4X. Meraki’s site-to-site VPN solutions are lauded for their stability and ease of use, especially when compared to more complex Cisco VPN configurations.
In conclusion, while running beta firmware on production networks can be approached with caution, the 15.4X firmware branch seems to be a viable and effective solution for the “Meraki unable to fetch config” error. For organizations plagued by this issue, upgrading to firmware 15.4X, specifically versions 15.40 or 15.42, is strongly recommended. However, it’s crucial to be aware of the potential Client VPN and PCI compliance implications if those functionalities are critical to your network environment. Always test firmware updates in a controlled environment when possible and consult Meraki support for the latest information and specific guidance for your network setup.
