Dawit,
Cisco 4431 Integrated Services router has been the new generation devices and though even it is supported, may create some issues in some features.
For support, please make sure you update the MDF to minimum version 1.89 where this device is supported, check the release note for MDF 1.89 :
http://www.cisco.com/web/software/282812295/112257/Mdf.CS30.v1-89.readme
4431 ISR (1.3.6.1.4.1.9.1.1935) is mentioned here as new Device Types Defined in Mdf.CS30.v1-89.zip.
If you have the right MDF package and you face any specific feature issue with this device, you can check separately on why it is failing.
-Thanks
Vinod
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-Thanks
Vinod
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