Restoring Disk0: when it breaks in 12k XOR routers

Question

Hi all,
How to restore the Disk0: contents like corrupted boot image,configurations and file system on the disk0: in 12k routers running with XOR Build.
1)Is there any options available ?
2)IS there any best practices to deal with this above ?
3)Is it possible that only primary RP's config/file system got corrupted and the backup RP is fine? Would then help for a switchover??
4)IS there any way to check the healthy of the config/file system before rolling back things after a power cycle??

Answer 1

The firmware is up to date on the Cradlepoint CBR400.  It's definitely not in the CBR400, i've already pursued that.  Even though NAT is required on my end for multiple phones, disabling NAT by setting the CBR400 to IP passthrough mode to allow the phone to pickup the DHCP address from Verizon didn't work either.  This works on a SIP softphone (Bria by Counterpath) and a laptop but not directly to a Polycom phone.  Very odd scenario... The traffic coming from the Bria app on the laptop probably looks slightly different (no QoS tagging for one) than the traffic directly from the Polycom phone, which leads me to believe Verizon is doing some specialized handling of SIP traffic when they see it (probably SIP ALG of some sort) which is breaking hosted VoIP.  For premise based VoIP it might work but a hosted VoIP scenario is different.  Since the server is in the cloud, if Verizon is manipulating those packet headers before it reaches the server (re-writing a real IP with a LAN IP for example), the hosted server won't know where the traffic came from to be able to communicate back and establish the call (SIP signal or audio session).  This is very common (SIP ALG) in today's routing devices.  This is a whole separate scenario to double NAT which I believe they are also doing.  This would explain why the SIP softphone Bria won't work with Verizon 4G LTE behind the NAT of the Cradlepoint CBR400.
Bottom line is that over the past week i've tested over a dozen scenarios with the 4G LTE and the Cradlepoint CBR400 and determined Verizon is breaking it.  AT&T iPhone tether actually shows some promise except that the Cradlepoint CBR400 isn't compatible with it via USB.  I'd be very curious to know if a compatible AT&T USB device would suffer from the same issues.  In light of my iPhone tether testing i'd have to say no.