topic Re: Connectivity issue to Nexus 9000 AlwaysOn Sandbox in DevNet Sandbox

Connectivity issue to Nexus 9000 AlwaysOn Sandbox

jozef-baros — Wed, 04 Mar 2026 15:28:22 GMT

Hello Community,

I am new here and trying to get access to Nexus 9000 AlwaysOn Sandbox, I want to practise CLI commands. In the connectivity details I see SSH port 22, with sbx-nxos-mgmt.cisco.com hostname.

Howewer I am not able to ping, nor connect sbx-nxos-mgmt.cisco.com.

C:\Users\HKLG3275>ping sbx-nxos-mgmt.cisco.com

Pinging sandbox-nxos-1.cisco.com [131.226.217.151] with 32 bytes of data:
Request timed out.
Request timed out.

SSH is also not working.

Can you help me? How Can I connect via SSH to CLI and practise?

Thank You

Re: Connectivity issue to Nexus 9000 AlwaysOn Sandbox

Jesus Illescas — Tue, 10 Mar 2026 19:27:49 GMT

@jozef-baros the nexus always on sandbox is working now. The always on sandboxes are open and sometimes users remove configuration that breaks connectivity, when this happens, the sandboxes are automatically reset after few minutes. So the best is to try again after a while.

If you need a dedicated environment is best to get a reservable sandbox.

By the way, ping is blocked towards the whole sandbox infrastructure, so timing out there is expected.

Re: Connectivity issue to Nexus 9000 AlwaysOn Sandbox

jozef-baros — Wed, 11 Mar 2026 07:23:41 GMT

Hello @Jesus Illescas

thank You for your answer. Unfortunately, this is still not working for me. Maybe I am doing something wrong?

Putty output attached, command prompt as below:

cmd:
C:\Users\HKLG3275>ssh sbx-nxos-mgmt.cisco.com
ssh: connect to host sbx-nxos-mgmt.cisco.com port 22: Connection timed out

I have created envoironment, see the I/O tab, tried to ssh to the server, but I am getting a connection timeout. The https works, but there is only API, and I would like to train in command line. Do you have any steps how to achieve this?

Thank You.

Jozef

Re: Connectivity issue to Nexus 9000 AlwaysOn Sandbox

Jesus Illescas — Wed, 11 Mar 2026 12:56:11 GMT

I tested the connection to the sandbox several times during my morning @jozef-baros and had no issues.

I think is important to verify what works and what doesn't work on your end. Most of the times connection timed out could be because the port is closed, bad configuration, already full by requests or dns.

Assuming you got a reservation and you have valid credentials (they expire) try these commands.

nslookup sbx-nxos-mgmt.cisco.com Test-NetConnection -ComputerName sbx-nxos-mgmt.cisco.com -Port 22 -InformationLevel "Detailed" telnet sbx-nxos-mgmt.cisco.com 22 (you might need to enable telnet on your end) ssh <YOUR_USER>@sbx-nxos-mgmt.cisco.com -p 22 -vv

I don't use windows so in my case the outputs are a bit different, but for reference this is how I see it.

❯ dig sbx-nxos-mgmt.cisco.com ; <<>> DiG 9.10.6 <<>> sbx-nxos-mgmt.cisco.com ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 27846 ;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0 ;; QUESTION SECTION: ;sbx-nxos-mgmt.cisco.com. IN A ;; ANSWER SECTION: sbx-nxos-mgmt.cisco.com. 5 IN CNAME sandbox-nxos-1.cisco.com. sandbox-nxos-1.cisco.com. 5 IN A 131.226.217.151 ;; Query time: 3 msec ;; SERVER: 192.168.86.1#53(192.168.86.1) ;; WHEN: Wed Mar 11 12:48:14 WET 2026 ;; MSG SIZE rcvd: 86 ❯ telnet sbx-nxos-mgmt.cisco.com 22 Trying 131.226.217.151... Connected to sandbox-nxos-1.cisco.com. Escape character is '^]'. SSH-2.0-OpenSSH_9.1 PKIX[13.5] Invalid SSH identification string. Connection closed by foreign host. ❯ ssh sbx-nxos-mgmt.cisco.com Warning: Permanently added 'sbx-nxos-mgmt.cisco.com' (RSA) to the list of known hosts. ** WARNING: connection is not using a post-quantum key exchange algorithm. ** This session may be vulnerable to "store now, decrypt later" attacks. ** The server may need to be upgraded. See https://openssh.com/pq.html User Access Verification (xxxxxxx@sbx-nxos-mgmt.cisco.com) Password: Bad terminal type: "xterm-ghostty". Will assume vt100. Cisco NX-OS Software Copyright (c) 2002-2025, Cisco Systems, Inc. All rights reserved. Nexus 9000v software ("Nexus 9000v Software") and related documentation, files or other reference materials ("Documentation") are the proprietary property and confidential information of Cisco Systems, Inc. ("Cisco") and are protected, without limitation, pursuant to United States and International copyright and trademark laws in the applicable jurisdiction which provide civil and criminal penalties for copying or distribution without Cisco's authorization. Any use or disclosure, in whole or in part, of the Nexus 9000v Software or Documentation to any third party for any purposes is expressly prohibited except as otherwise authorized by Cisco in writing. The copyrights to certain works contained herein are owned by other third parties and are used and distributed under license. Some parts of this software may be covered under the GNU Public License or the GNU Lesser General Public License. A copy of each such license is available at http://www.gnu.org/licenses/gpl.html and http://www.gnu.org/licenses/lgpl.html *************************************************************************** * Nexus 9000v is strictly limited to use for evaluation, demonstration * * and NX-OS education. Any use or disclosure, in whole or in part of * * the Nexus 9000v Software or Documentation to any third party for any * * purposes is expressly prohibited except as otherwise authorized by * * Cisco in writing. * *************************************************************************** nexus#

And to be on the same page, when you say https works, you mean a RESTCONF connection to the nexus sandbox works? Or you mean the web portal used by the sandbox platform (where you reserve and see details of the environment like crendentials), those are different systems.

Re: Connectivity issue to Nexus 9000 AlwaysOn Sandbox

jozef-baros — Wed, 11 Mar 2026 13:45:26 GMT

Thank You @Jesus Illescas for detailed steps.

I have tried all this also from ubuntu, and also from windows:

ssh jozef.baros@sbx-nxos-mgmt.cisco.com -p 22 -vv OpenSSH_for_Windows_9.5p2, LibreSSL 3.8.2 debug2: resolving "sbx-nxos-mgmt.cisco.com" port 22 debug1: Connecting to sbx-nxos-mgmt.cisco.com [131.226.217.151] port 22. debug1: connect to address 131.226.217.151 port 22: Connection timed out ssh: connect to host sbx-nxos-mgmt.cisco.com port 22: Connection timed out

here also

PS C:\Users\HKLG3275> Test-NetConnection -ComputerName sbx-nxos-mgmt.cisco.com -Port 22 -InformationLevel "Detailed" WARNING: TCP connect to (131.226.217.151 : 22) failed WARNING: Ping to 131.226.217.151 failed with status: TimedOut ComputerName : sbx-nxos-mgmt.cisco.com RemoteAddress : 131.226.217.151 RemotePort : 22 NameResolutionResults : 131.226.217.151 MatchingIPsecRules : NetworkIsolationContext : Internet IsAdmin : False InterfaceAlias : Ethernet 6 SourceAddress : 10.237.178.137 NetRoute (NextHop) : 10.237.178.254 PingSucceeded : False PingReplyDetails (RTT) : 0 ms TcpTestSucceeded : False

When I was mentioning the https, I mean RESTCONF web page of https://sbx-nxos-mgmt.cisco.com/ is working (NX-API Sandbox). I was trying my office network, also home network, hotspot from mobile, but still I am not able to reach cli, port22.Also tried bash, ubuntu, putty..

Thank You for your help. I will keep trying.

Re: Connectivity issue to Nexus 9000 AlwaysOn Sandbox

jozef-baros — Wed, 11 Mar 2026 14:52:42 GMT

tried again with mobile hotspot and working!!! something must block port 22 in my corporate network

Thank You!

Re: Connectivity issue to Nexus 9000 AlwaysOn Sandbox

Jesus Illescas — Wed, 11 Mar 2026 14:53:42 GMT

@jozef-baros is a bit strange your case. From your output and your comment about the web interface, I can see DNS is working.

I tested on my end now ssh towards the nexus always on sandbox and it worked. I tested on my work laptop, but also on a personal one (both macos), using my home wifi and my cellphone and no issues in either case.

You said, you tested on ubuntu and windows, but on different physical machines? VMs?. Can you share from which country you are connecting? I can ask the sandbox team if there is a FW rule in any place, although you can connect using HTTP.

Reviewing the config on the nexus device, I don't see any filter.

Re: Connectivity issue to Nexus 9000 AlwaysOn Sandbox

Jesus Illescas — Wed, 11 Mar 2026 15:00:41 GMT

Glad you found the issue @jozef-baros and thanks for sharing what happened in your case.