Netflow Network Issues

Unanswered Question
May 9th, 2009

At one of our locations we had our ISP enable netflow on our 2851, then connected it to our PRTG server.

Ever since we did that a few days ago we've seen a few weird network issues. A program we use to download files from multiple sources now struggles to complete downloads. Internally when we use programs to launch other programs via windows run commands, they now fail.

I'm not 100% sure netflow is causing these issues, but they all appeared as soon as we enabled netflow.


Howies_2352659# show ip flow export

Flow export v5 is enabled for main cache

Exporting flows to (9996)

Exporting using source interface GigabitEthernet0/0

Version 5 flow records

13385 flows exported in 448 udp datagrams

0 flows failed due to lack of export packet

0 export packets were sent up to process level

0 export packets were dropped due to no fib

0 export packets were dropped due to adjacency issues

0 export packets were dropped due to fragmentation failures

0 export packets were dropped due to encapsulation fixup failures

Howies_2352659#show ip flow interface


ip route-cache flow


I have this problem too.
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pkurdziel Sat, 05/09/2009 - 19:48

All ip route-cache flow does is it enables NetFlow accounting for packets that are received by the interface.

ip route-cache flow was replaced by ip flow {ingress | egress}

What exactly did the ISP do? Did they add ip route-cache flow to Howies_2352659? What else did they do?


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