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New Member

Help! Ping works randomly. Internet seems to work fine.


 Router- Ciso 3925. ASA-5505.

This is new. I changed NAT on our router from 'classic NAT' to NAT NVI.

 After making the change I accessed the internet and pinged servers from and to other branch offices internally (Comcast ENS network) and all seemed fine.

Later I did the same pings or tracert I realized they work fine once and the next ping fails. Able to access internet. But if I ping to the same site (eg:Yahoo) it fails randomly. When I do contimous pings using '-t' no packet loss at all.

As long as internet service is not disrupted its fine (will have time to make change) but I am afraid internet access will be intermittent too.


I can't understand whats wrong. Is it the speed duplex setting?? On router interface its duplex full, speed 100 and on ASA its auto, auto. But thats how its been from before. If thats the case can I change speed/duplex settings remotely without loosing access??? Please advise

OR, Should I revert back to classic NAT?


Any insight is appreciated.

Kinda urgent. Have to fix this ASAP.


Hello i would try the port



i would try the port setting first before reverting e nat.


either set the router interface to auto negotiate or hardcode the fe interface to the same settings of the router




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New Member

Thanks for the reply Paul.The

Thanks for the reply Paul.

The port setting (speed/duplex) are correct. I was looking at the wrong interface.

My apologies.

Is there any other thing that might be causing this??

If not I will revert back to classic NAT.

Hellomtu settings -cabling


mtu settings -cabling etc.. Very hard to troubleshoot without seeing your config and logging readouts

possible coincidence that now you have an unrelated issue?

have you tried your tests from the router sourcing from the LAN interface?



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New Member

 Reverted back to previous


Reverted back to previous config and all is working perfect.

Is it NVI NAT? But it works just fine at our other branch office which I had configured the whole network (router, ASA).


The branch I am currently working on was done from before. Maybe I am missing something or I need to dig deeper in the config. Will hold off for now.


Thanks again for your time Paul.

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