Hi Guys was wondering if somebody could help me please, i have a Vigor 2860 router setup with a VPN to a datacenter cisco router, the VPN seems to drop out after 20ish mins then reconnect, not sure what is going on.

Ive put the syslog from the router below, any help appreciated, the first line is were the VPN reconnects and we gain access, we lost connection at the bottom of this post.

2015-09-22 21:16:40 IKE ==>, Next Payload=ISAKMP_NEXT_HASH, Exchange Type = 0x5, Message ID = 0x43c80bad
2015-09-22 21:16:15 [L2L][UP][IPSec][@2:Exchange]
2015-09-22 21:16:15 IPsec SA established with 31.193.6.224. In/Out Index: -2/-2
2015-09-22 21:16:15 IPsec SA #168 will be replaced after 23925 seconds
2015-09-22 21:16:15 IKE <==, Next Payload=ISAKMP_NEXT_HASH, Exchange Type = 0x20, Message ID = 0x66345e91
2015-09-22 21:16:15 IKE ==>, Next Payload=ISAKMP_NEXT_HASH, Exchange Type = 0x20, Message ID = 0x66345e91
2015-09-22 21:16:15 Responding to Quick Mode from 31.193.6.224
2015-09-22 21:16:15 [IPsec dial-in] Client subnet ac192980/ffffff80 match VPN[1] remote subnet setting.
2015-09-22 21:16:15 Receive client L2L remote network setting is 192.168.11.0/24
2015-09-22 21:16:15 IKE <==, Next Payload=ISAKMP_NEXT_HASH, Exchange Type = 0x20, Message ID = 0x66345e91
2015-09-22 21:16:10 [L2L][UP][IPSec][@2:Exchange]
2015-09-22 21:16:10 IPsec SA established with 31.193.6.224. In/Out Index: -2/-2
2015-09-22 21:16:10 IPsec SA #167 will be replaced after 23850 seconds
2015-09-22 21:16:10 IKE <==, Next Payload=ISAKMP_NEXT_HASH, Exchange Type = 0x20, Message ID = 0xa5df1395
2015-09-22 21:16:10 IKE ==>, Next Payload=ISAKMP_NEXT_HASH, Exchange Type = 0x20, Message ID = 0xa5df1395
2015-09-22 21:16:10 Responding to Quick Mode from 31.193.6.224
2015-09-22 21:16:10 [IPsec dial-in] Client subnet ac192980/ffffff80 match VPN[1] remote subnet setting.
2015-09-22 21:16:10 Receive client L2L remote network setting is 192.168.15.0/24
2015-09-22 21:16:10 IKE <==, Next Payload=ISAKMP_NEXT_HASH, Exchange Type = 0x20, Message ID = 0xa5df1395
2015-09-22 21:16:07 DOUBLE free for 817d4230: 7a99 from Nr
2015-09-22 21:16:07 DOUBLE free for 817d4230: 7a99 from Nr
2015-09-22 21:16:07 IKE ==>, Next Payload=ISAKMP_NEXT_HASH, Exchange Type = 0x5, Message ID = 0x4093bd53
2015-09-22 21:16:07 IKE ==>, Next Payload=ISAKMP_NEXT_HASH, Exchange Type = 0x5, Message ID = 0x3c8fb94f
2015-09-22 21:16:07 IKE_RELEASE VPN : L2L Dial-in, Profile index = 2, Name = Exchange, ifno = 12
2015-09-22 21:16:07 [L2L][DOWN][IPSec][@2:Exchange]
2015-09-22 21:16:07 IKE_RELEASE VPN : L2L Dial-in, Profile index = 2, Name = Exchange, ifno = 10
2015-09-22 21:16:07 [L2L][DOWN][IPSec][@2:Exchange]
2015-09-22 21:16:07 PPP Closed : Idle Time-out (VPN : L2L Dial-in, Profile index = 2, Name = Exchange, ifno = 12)
2015-09-22 21:16:07 PPP Closed : Idle Time-out (VPN : L2L Dial-in, Profile index = 2, Name = Exchange, ifno = 10)