This document describes the reasons behind telemetry connections failing and how to restore them.
Customers are required to use either of these three options to resolve the issue.
Option 1: Upgrade Catalyst Center to 2.3.7.11 or 2.3.7.9 PSMU60 or 2.3.7.10 PSMU110. The SMU (Software Maintenance Update) will be available for upgrade under System > Software Management in the Cisco Catalyst Center GUI.
Option 2: Upgrade the effected Cisco IOS XE device to 17.12.5 or later of a Cisco recommended release.
Option 3: Force-push telemetry from the Catalyst Center GUI and update the hash algorithm for the trustpoint to sha512 on the device as follows:
device# show crypto pki certificates verbose sdn-network-infra-iwan
Sample Output:
Certificate
Status: Available
Version: 3
Certificate Serial Number (hex): 18831279321B12FA
Certificate Usage: General Purpose
Issuer:
cn=sdn-network-infra-ca
Subject:
Name: device.example.net
cn=C9300-48U_SN12345678_sdn-network-infra-iwan
hostname=device.example.net
Validity Date:
start date: 11:39:55 cdt Jul 10 2025
end date: 11:39:55 cdt Jul 16 2025
renew date: 06:51:54 cdt Jul 15 2025
...
Note: If the end date and renew date are before the current date on the device then the certificate has expired.
Sample Output:
Device# show logging %PKI-2-CERT_RENEW_FAIL: Certificate renewal failed for trustpoint sdn-network-infra-iwan
Reason : Failed to get ID certificate from CA server sdn-network-infra-iwan:Certificate renewal failed.
Sample Output:
Device#show tel con all
Telemetry connections
Index Peer Address Port VRF Source Address State State Description
-----------------------------------------------------------------------------------------
36284 x.x.x.x 25103 0 x.x.x.x Connecting Connection request made to transport handler
Note: In this example the telemetry connection is not up, just in the Connecting state.
crypto pki trustpoint sdn-network-infra-iwan no hash sha256 hash sha512
FAQ: Does installing the SMU fix an already impacted system, or is it preventive?
The SMU is a preventive fix and must be installed before the issue occurs. If the issue has already occurred, installing the SMU will not automatically clear the issue. To recover existing failed systems, select Option 3.
| Revision | Publish Date | Comments |
|---|---|---|
1.0 |
08-Apr-2026
|
Initial Release |