topic Re: CML Sandbox External Connector in DevNet Sandbox

CML Sandbox External Connector

imanless — Thu, 05 Jun 2025 07:02:37 GMT

Hello. I am using sandbox version of Cisco Modeling Labs. I am writing this to ask in which subnet should i configure my device connected to the external connector. If I use bridged mode, there is no dynamic ip assignment. But if I use NAT mode, then an ip in the 192.168.255.0 subnet is assigned, which is not accessible. can anyone guide me what can be done about it ?

Re: CML Sandbox External Connector

Torbjørn — Thu, 05 Jun 2025 07:17:11 GMT

I believe external outbound connectivity isn't allowed from the sandboxes. I have seen a couple of these questions recently, is this something you can confirm @jokearns1?

Re: CML Sandbox External Connector

imanless — Thu, 05 Jun 2025 07:23:44 GMT

But in the sample topology which is already present in the CML sandbox, has devices which you can ssh into. So i thought may it is also possible to create a new lab and have an external connector in it and be able to ssh into to the devices in that lab.

Re: CML Sandbox External Connector

Torbjørn — Thu, 05 Jun 2025 08:06:01 GMT

Sorry, I misinterpreted your question. Yes that is possible.

You will need to configure your external connector to use bridge0 and configure your devices in 10.10.20.0/24. Note that traffic is only allowed inbound to CML and you won't be able to establish connections outbound from CML.

Re: CML Sandbox External Connector

imanless — Thu, 05 Jun 2025 08:20:52 GMT

Thankyou. Are all the addresses other than the one mentioned in the sample topology available for use in the 10.10.20.0/24 subnet ?

Re: CML Sandbox External Connector

Torbjørn — Thu, 05 Jun 2025 11:15:10 GMT

I would assume that all other addresses than .1, .50 and .170-178 are free to use. If you shut down the "default lab" nodes you can use .170-178 as well. This is however not explicitly documented anywhere.

Re: CML Sandbox External Connector

jokearns1 — Thu, 05 Jun 2025 20:55:24 GMT

Hi @imanless

@Torbjørn is correct. the 192.168.255.0 subnet is not routable within our network may be a remnant of an old similation. Use a free 10.10.20.0 IP. i.e. 10.10.20.150.
Either way, we need to document this better on our side. I will get with the team and we will update the documentation.
Joe

Re: CML Sandbox External Connector

imanless — Fri, 06 Jun 2025 09:28:36 GMT

Thanks a lot.

Re: CML Sandbox External Connector

jerry7494 — Thu, 12 Jun 2025 06:50:24 GMT

Thanks man