Migrating from 3925 to ASR1001

[IntraTech]

Hello,

Is it feasible to migrate from two 3925E-SEC/K9 routers to 2  ASR1001-X routers?

What's the level of effort?

How would you do this?

Is there a tool that can be used?

Any path, opinions or options would be appreciated.

[balaji.bandi]

I do not see any issue, if you already have devices in place, there may be some command syntax changed, So take the backup and change acordingly and paste in ASR see what config getting error and fix it.

how big is the config, what role exiting device doing ? taking them offline testing ( do you get downtime ?)

[Richard Burts]

I doubt that you would be able to do a direct copy from one router and paste to the other router migration. We do not know what features of the 3925 you are running and so can not know if the way some features are implemented may have changed (or whether some features used on the 3925 may not be implemented on the 1001). I suggest that you take good backup of the configurations of the current routers, go through the configs and make sure that you understand the functionality being implemented, and then part by part see if you can configure that functionality on the new router.

[IntraTech]

Thanks because of the WFH situation the company is in, I do not have access to the ASRs and Nexus switches, they are in the office where we are not allowed to go. All I have access to currently are the current live switches and routers. I can look for features and things in the config and try to see if they are supported on the new ones. Is that the best way you recommend this? I just really need some path that I can execute to try to push this along.

[balaji.bandi]

as suggested, there is no straight way to cut over, and we do not have any visibility of what is configured, it may work may not, some point of time you need to do Physical Move.

So if you have any help onsite, ask them to put them online connect to management access, so you can test the config.

[IntraTech]

I really have no idea where to start. Can you give me some advice please. Is there anything that you think isn't compatible?

[balaji.bandi]

at this stage personally, i do not have any cards to offer you, because both are routers,  as I mentioned config syntax may be different, you looking for blind cutover that is your risk without checking the compatible config works in ASR or not.

On a side note, 1, you can contact a local cisco partner to get help 2. contact cisco tac with config.

In either case, what is your option for cutover ( you can not go onsite ? who will be doing the cable moves ? how surely does the engineer  understand the change over from OLD Router to New  Router ?)

[IntraTech]

I will go on site for the cutover. I just need a plan before I do.

[paul driver]

Hello
If you don’t have access to the asr rtrs then the other alternative would be simulation, GNS3 using CSR1000v image could be the best shot at compiling the necessary ASR configuration to be applied to the actual rtrs as/when you are ready.

[balaji.bandi]

Unfortunately - there is no straight forward as per the scenario, But there is no Gaurantee that cut over go well as expected, if you do not test offline before putting production. i would not advise any other option than working real device to explore the config and port on new device.

(until you looking more dowtime, more visits to sites)

[Richard Burts]

Without knowing more about your environment it is difficult to give good advice. For basic things like IP addressing/subnetting and routing they should pretty much be the same (though there might be some differences such as do you activate a routing protocol on an interface by using a network statement under the protocol configuration or do you activate it by configuring in interface configuration mode? If you are using more advanced features, perhaps like Policy Based Routing or QOS, you need to be more careful. I worked with someone a while back who was transitioning to a new platform. Their configuration included PBR and we discovered that while the new platform supported the basic operations it did not support the verify-availability option.

So as I suggested before you should carefully go through the configuration of the existing platform. Make sure that you understand what it is doing. And then function by function apply the configuration to the new platform.

[IntraTech]

When you go through configuration what are some things to note and look out for. What's the simplest way to ascertain features.

[IntraTech]

How would I decide what to do with licensing during the migration? Are there licenses on the current device I'd migrate or need to buy on the new devices to support features or hardware?

[Richard Burts]

For 3925E-SEC/K9 in general licenses do not transfer. You would need to verify what licenses are active on the existing router and then look for equivalent licenses for the ASR.