RV042 reports tunnel disconnection without connection for foreign IP, Security issue?

Question

Dear all,
we are recently working with a RV042 router, with VPN group tunnel (connectig throw shrew VPN). Last days router is logging disconnections like this ("[XXX]" text replaced for security reasons)
Dec 9 17:02:58 2014 XXX VPN Log: (grpips0)[72] [XXX].[XXX].[XXX].0/24=== ...113.240.173.58===?: [Tunnel Disconnected] instance with peer 113.240.173.58 {isakmp=#0/ipsec=#0}
But NO RELATED "connections" (apart from our own controled connection/disconnection) is reported previously. Is this a security issue/breach?
(The foreign IP was left clear so if anyone knows about that particular IP, can make a comment.)
Thanks in advance. Regards, Juan.

Answer 1

Zach,
I will try to use that approach while using dynamic IPs to connect to VPN (cannot build an stable whitelist, and this can lead to connection lost in the near future until new IP is registered in the remote router).
What I do not understand is:
router logs a disconnection without a previous connection
no other activity is detected on the VPN (perhaps only spying?)
when I disconnect, two logs are generated (in order of appearance)
Dec [xxx] [xxx]:[xxx]:[xxx] 2014 3EFF-3196 VPN Log: (grpips0)[73] 192.168.2.0/24=== ...[xxx].[xxx].[xxx].[xxx]===?: [Tunnel Disconnected] instance with peer [xxx].[xxx].[xxx].[xxx]{isakmp=#0/ipsec=#0}
Dec [xxx] [xxx]:[xxx]:[xxx]2014 3EFF-3196 VPN Log: (grpips0)[73] [xxx].[xxx].[xxx].0/24=== ...[xxx].[xxx].[xxx].[xxx]===? #220: [Tunnel Established] ISAKMP SA established
when foreign IP disconnects, only one is generated (e.g. whitout #220)
Does this have an explanation?
Thanks again, Juan.