Cisco 4506 offline but not off

[Westwardal]

Hello,
I have a perplexing issue that surfaces randomly; usually on the weekend or at night.  What happens is I cannot ping my 4506 for 30min-2 hours.  For all effective purposes the network appears to be off; I can't ssh or see the can't see the network with show cdp commands.   When the network comes back online, I ssh into and look at show version but it shows the router as having been up for 17 weeks.

I'm looking for suggestions as where to look or tools/utilities I can use to diagnose this issue. 

Any suggestions are appreciated.

Thanks,

[marce1000]

 - Activate syslogging to a syslog-server and snmp trap logging for all traps to an snmp trap receiver. Look for errors around the problematic time-frames which may help resolve the issue. But also follow up on messages from the box during normal operation.

 M.

[balaji.bandi]

So your Router up but you lost connection ? are you trying to Login Local Lan from internet ?

suggest to connect console cable with Laptop and capture all Logs where possible to understand the issue.