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06-05-2025 12:02 AM - edited 06-05-2025 12:02 AM
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 ?
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06-05-2025 01:06 AM
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.
Get in touch: https://torbjorn.dev
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06-05-2025 04:15 AM
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.
Get in touch: https://torbjorn.dev

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06-05-2025 01:55 PM
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
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06-05-2025 12:17 AM
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?
Get in touch: https://torbjorn.dev
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06-05-2025 12:23 AM - edited 06-05-2025 12:23 AM
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.
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06-05-2025 01:06 AM
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.
Get in touch: https://torbjorn.dev
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06-05-2025 01:20 AM
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 ?
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06-05-2025 04:15 AM
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.
Get in touch: https://torbjorn.dev
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06-11-2025 11:50 PM
Thanks man

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06-05-2025 01:55 PM
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
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06-06-2025 02:28 AM
Thanks a lot.
