We use a V2920 dual-WAn router with two V120 modems. Each modem has its own ADSL line, provided by TalkTalk Business. The router is configured to keep both lines up permanently and we have a load balancing policy and some QoS for marshalling various traffic to the different lines.
My WAN2 port has starting reporting that it is 'bouncing'. In the log I get a load of PPPoE stuff - the log extract below shows a typical down/up/down cycle, which repeats over the course of 5 to 10 minutes.
The line sync is stable, this is only the PPP session that is dropping. The ISP (TalkTalk Business) predictably says there is nothing wrong their end, but they confirm they are seeing dozens of auth requests from the router.
All the while, WAN1, which is configured identically except for the static IP and username/password, is completely stable and generates very little traffic.
What could be causing this? I don't understand what the detailed PPPoE log is trying to tell me. Can anyone see any clues here?
SysT msg
19/06/2012 16:14:11 WAN 2 is down.
19/06/2012 16:14:12 WAN2 PPPoE ==> V:1 T:1 PADT ID:6
[...]
19/06/2012 16:14:47 WAN2 PPPoE <== V:1 T:1 PADS ID:6
19/06/2012 16:14:47 WAN2 PPPoE ==> Protocol:LCP(c021) ConfReq Identifier:0x00 MRU: 1500 ##
19/06/2012 16:14:50 WAN2 PPPoE ==> Protocol:LCP(c021) ConfReq Identifier:0x01 MRU: 1500 ##
19/06/2012 16:14:53 WAN2 PPPoE ==> Protocol:LCP(c021) ConfReq Identifier:0x02 MRU: 1500 ##
19/06/2012 16:14:54 statistic: WAN1: Tx 176 Kbps, Rx 62 Kbps (5 min average)
19/06/2012 16:14:54 statistic: Session Usage: 957 (5 min average)
19/06/2012 16:14:56 WAN2 PPPoE ==> Protocol:LCP(c021) ConfReq Identifier:0x03 MRU: 1500 ##
[... this all repeats several times...]
19/06/2012 16:33:59 WAN 2 is up.
19/06/2012 16:34:03 WAN2 PPPoE ==> Protocol:LCP(c021) EchoReq Identifier:0x01Magic Number: 0x0 00 00 ##
19/06/2012 16:34:06 WAN2 PPPoE ==> Protocol:LCP(c021) EchoReq Identifier:0x02Magic Number: 0x0 00 00 ##
19/06/2012 16:34:09 WAN2 PPPoE ==> Protocol:LCP(c021) EchoReq Identifier:0x03Magic Number: 0x0 00 00 ##
19/06/2012 16:34:12 WAN2 PPPoE ==> Protocol:LCP(c021) TermReq Identifier:0x04 ##
19/06/2012 16:34:15 WAN2 PPPoE ==> Protocol:LCP(c021) TermReq Identifier:0x05 ##
19/06/2012 16:34:18 WAN2 PPPoE ==> Protocol:LCP(c021) TermReq Identifier:0x06 ##
19/06/2012 16:34:19 WAN2 PPPoE <== Protocol:LCP(c021) EchoReq Identifier:0x00Magic Number: 0x4a2b b0 0f ##
19/06/2012 16:34:21 WAN 2 is down.
