The "no crypto engine accel" command turns off the hardware crypto card in your router, effectively having all encryption done in software by the CPU. There were some initial problems with these cards, but in general now they run fine and you shouldn't have to turn it off for specific traffic types to flow. I would probably suggest opening a TAC case so we can investigate this further.
As for the "RSA keys too weak" message, I presume this is coming up in your SSH client, correct? It must have some parameter in it that checks the length of the key it receives from the router and complains. You can regenerate the key on the router and make it longer by issuing the command:
sv3-5(config)#cry key gen rsa
The name for the keys will be: sv3-5.cisco.com
Choose the size of the key modulus in the range of 360 to 2048 for your
General Purpose Keys. Choosing a key modulus greater than 512 may take
a few minutes.
How many bits in the modulus : 1024
Generating RSA keys ...
You'll have to choose a key length longer than whatever length your SSH application is complaining about, I would think 1024 should suffice though.
DocumentationCode download linksGoalRequirementLimitationsSupported ISR and UCS-E ModelSupported ISRG2 and UCS-E Blades:Supported ISR4K and UCS-E Blades:Step by Step ConfigurationConfigure one of the connectivity options to access the Cisco IMC from the n...
Firepower Threat Defense (NGFWv) on UCS E-series - Transparent Mode in HA
DocumentationCode download linksGoalRequirementLimitationsSupported ISR and UCS-E ModelSupported ISRG2 and UCS-E Blades:Supported ISR4K and UCS-E Blades:Step by Step ConfigurationCo...
I am currently unable to specify "crypto keyring" command when configuring VPN connection on my cisco 2901 router.
The following licenses have been activated on my router :