How can i montior a VPN Tunnel between two router by ip sla?

[Raimund Schimanovits]

Hello

I have 2 router with a vpn tunnel connected. The problem is that sometimes i have a paket loss on the tunnel. So how can i monitor this? Why is this possible? 

pls help me

[Rahul Kumar Mishra]

IP sla will be helpful if you have two or more internet connection between these two routers and you can configure your router to chose any of the path based on sla monitoring. If you want to monitor packet drops/latency for a single link  there is no use of IP sla. Rather you should use some latency monitoring tools such as prtg, mrtg etc.

[Raimund Schimanovits]

Hello

I have already Prtg running and i have no packet drops. The problem is that my software colleague said that he had packet drops on the vpn tunnel to the destination. So how can i find out where the problem is? There is no log entry in the router and the vpn was up. So how can i debug the vpn.

These are the only log entries

%DUAL-5-NBRCHANGE: EIGRP-IPv4 1: Neighbor 10.100.0.1 (Tunnel0) is down: holding time expired

 %DUAL-5-NBRCHANGE: EIGRP-IPv4 1: Neighbor 10.100.0.1 (Tunnel0) is up: new adjacency

Is it possible that is can produce packet loss?

Thanks

[Rahul Kumar Mishra]

These logs mean the eigrp neighborship over tunnel is getting down and up. It will obviously affect your routing through tunnel. Routing will only happen when eigrp neighborship is up.  It may be caused by wrong eigrp timers configured on both end of tunnel if there is no link down issue from ISP. Please get the eigrp configuration of both ends reviewed.