01-12-2009 09:58 PM
Hi all,
I'm trying to collect netflow data from a remote site which only has one Cisco 881 router and is connected to our corporate WAN using an IPSec VPN tunnel. According to Cisco and bug CSCsk25481 it appears as though only the new âFlexible-Netflowâ will work over IPSec VPN tunnels when the router that generates the IPSec VPN tunnel is trying to send netflow info, as long as you have IOS version 12.4(17.2)T. I've tried to configure this using the commands below but it still doesn't send any netflow data to our NTA. The router is being monitored by Solarwinds Orion using the Lo0 IP address. The VPN tunnel does go through a firewall but all ports are open for VPN's for both UDP and TCP.
Here's what Cisco sayâ¦
IOS does not encrypt NetFlow export packets which originate from the router itself. This is day 0
functionality as features are not applied to NetFlow export packets and never have been.
The solution to this does not fix the above for Cisco's older netflow-switch code but rather
provides the ability to encrypt outgoing NetFlow export packets for the newer flexible-netflow
product.
Here's the config on the routerâ¦
flow exporter export-to-DCRAP014
destination 10.254.17.14
source Loopback0
transport udp 9996
!
!
flow monitor flow-monitor
record netflow-original
exporter export-to-DCRAP014
interface FastEthernet4
ip flow monitor flow-monitor input
ip flow monitor flow-monitor output
interface Vlan1
ip address 10.254.41.1 255.255.255.0
ip flow monitor flow-monitor input
ip flow monitor flow-monitor output
Is my config of the router wrong or am I missing something?
wireshark also doesn't pick up any traffic from the remote router on the Orion server so it doesn't look like the router is sending anything.
many thanks
Dave
01-14-2009 02:44 AM
Can anyone please help me with this, even guess at what it could be or point me in a direction where I might find more help?
many thanks
Dave
01-16-2009 08:23 AM
Not just yet - i am having the same problem with a Cisco 1801 using a VPN tunnel to a fortigate firewall!
Currently using standard netflow, haven't experimented with flexible netflow yet, let me know if yo ucome across anything, i'll do the same!
Cheers
Jonathan
01-17-2009 02:11 AM
Hi Jonathan,
I was just told by solarwinds that they don't support flexible netflow so I don't think I'll be taking this any further. It seems I'll just have to rely on ip accunting on the router to help debug issues.
I hope you find a solution.
Dave
01-19-2009 12:57 AM
Hi Dave,
Thanks for that, it is worth knowing. We are currently trialing the Fluke NetFLOW tracker analyser, so will probably see if that will support it.
Another possible soloution is to use "Virtual Tunnel INterfaces" as opposded to standard interface crypto map statements - apparently this may get the standard netflow exporting correctly.
Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community: