I have a remote branch office that is using an ISR which serves as their internet connection, wireless, and VPN. The issue I'm having currently is in regards to the PPTP VPN function that is used by the office staff. They recently began complaining about the performance and noted that they can connect, but after a while it becomes unusable. It hangs, forcing them to disconnect and reconnect to even be able to ping anything.
So I log on, check the config and realize I don't know a whole lot about pptp connections. I run a debug on some ppp and vpdn options, and ran into this when the issue began to start:
*Dec 5 01:01:44.684: PPTP tnl 04FCB:________: timeout -> echo state change Idle to wt-echorp
*Dec 5 01:01:44.752: PPTP tnl 04FCB:________: EchoRP -> echo state change wt-echorp to Idle
*Dec 5 01:01:58.332: Vi5 UNKNOWN(0xBC2C): Received short packet, paklen 54 < ppplen 41471, discarding packet
*Dec 5 01:01:58.332: Vi5 UNKNOWN(0x9AF2): Received short packet, paklen 62 < ppplen 49020, discarding packet
*Dec 5 01:01:58.332: Vi5 UNKNOWN(0xF04D): Received short packet, paklen 62 < ppplen 55498, discarding packet
*Dec 5 01:01:58.332: Vi5 UNKNOWN(0xA4B7): Received short packet, paklen 54 < ppplen 2652, discarding packet
*Dec 5 01:01:58.332: Vi5 UNKNOWN(0x92CC): Received short packet, paklen 62 < ppplen 10916, discarding packet
*Dec 5 01:01:58.332: Vi5 UNKNOWN(0xD4B1): Received short packet, paklen 62 < ppplen 4442, discarding packet
*Dec 5 01:01:58.332: Vi5 UNKNOWN(0xC0B5): Received short packet, paklen 54 < ppplen 40175, discarding packet
*Dec 5 01:01:58.332: Vi5 UNKNOWN(0xCA13): Received short packet, paklen 42 < ppplen 1813, discarding packet
*Dec 5 01:01:58.332: Vi5 UNKNOWN(0xFA7C): Received short packet, paklen 42 < ppplen 5163, discarding packet
*Dec 5 01:01:58.332: Vi5 UNKNOWN(0xB697): Received short packet, paklen 42 < ppplen 25442, discarding packet
*Dec 5 01:01:58.332: Vi5 UNKNOWN(0xE4DD): Received short packet, paklen 42 < ppplen 24769, discarding packet
*Dec 5 01:01:58.332: Vi5 UNKNOWN(0x8A6E): Received short packet, paklen 42 < ppplen 48206, discarding packet
*Dec 5 01:01:58.332: Vi5 UNKNOWN(0x96B9): Received short packet, paklen 42 < ppplen 42327, discarding packet
*Dec 5 01:01:58.332: Vi5 UNKNOWN(0xF874): Received short packet, paklen 42 < ppplen 26530, discarding packet
*Dec 5 01:01:58.340: Vi5 UNKNOWN(0x8834): Received short packet, paklen 42 < ppplen 11555, discarding packet
*Dec 5 01:01:58.340: Vi5 UNKNOWN(0xA63A): Received short packet, paklen 42 < ppplen 33855, discarding packet
*Dec 5 01:01:58.340: Vi5 UNKNOWN(0xD430): Received short packet, paklen 42 < ppplen 50068, discarding packet
*Dec 5 01:01:58.340: Vi5 UNKNOWN(0xD2EF): Received short packet, paklen 42 < ppplen 6442, discarding packet
*Dec 5 01:01:58.340: Vi5 UNKNOWN(0xBE2C): Received short packet, paklen 42 < ppplen 41025, discarding packet
*Dec 5 01:01:58.352: Vi5 UNKNOWN(0xFE5C): Received short packet, paklen 42 < ppplen 2956, discarding packet
*Dec 5 01:01:58.352: Vi5 UNKNOWN(0xDCBE): Received short packet, paklen 42 < ppplen 17398, discarding packet
*Dec 5 01:01:58.352: Vi5 UNKNOWN(0xA62E): Received short packet, paklen 42 < ppplen 53058, discarding packet
*Dec 5 01:01:58.360: Vi5 UNKNOWN(0xF847): Received short packet, paklen 42 < ppplen 20012, discarding packet
*Dec 5 01:01:58.360: Vi5 UNKNOWN(0xD07F): Received short packet, paklen 42 < ppplen 4078, discarding packet
*Dec 5 01:01:58.360: Vi5 UNKNOWN(0xBAD0): Received short packet, paklen 42 < ppplen 46723, discarding packet
*Dec 5 01:01:58.360: Vi5 UNKNOWN(0xC2E7): Received short packet, paklen 42 < ppplen 57976, discarding packet
*Dec 5 01:01:58.360: Vi5 UNKNOWN(0xB47D): Received short packet, paklen 42 < ppplen 54932, discarding packet
*Dec 5 01:01:58.360: Vi5 UNKNOWN(0xDA0B): Received short packet, paklen 42 < ppplen 41206, discarding packet
*Dec 5 01:01:58.360: Vi5 UNKNOWN(0xD204): Received short packet, paklen 42 < ppplen 54706, discarding packet
*Dec 5 01:01:58.360: Vi5 UNKNOWN(0xB464): Received short packet, paklen 54 < ppplen 60562, discarding packet
*Dec 5 01:01:58.360: Vi5 UNKNOWN(0xD07B): Received short packet, paklen 54 < ppplen 25823, discarding packet
*Dec 5 01:01:58.556: Vi5 UNKNOWN(0x9017): Received short packet, paklen 42 < ppplen 58499, discarding packet
*Dec 5 01:01:58.640: Vi5 UNKNOWN(0x8C2F): Received short packet, paklen 62 < ppplen 36287, discarding packet
*Dec 5 01:01:58.704: Vi5 UNKNOWN(0xD2F2): Received short packet, paklen 54 < ppplen 1474, discarding packet
*Dec 5 01:01:59.304: Vi5 UNKNOWN(0xA297): Received short packet, paklen 54 < ppplen 1511, discarding packet
*Dec 5 01:01:59.724: Vi5 UNKNOWN(0x8A4C): Received short packet, paklen 1154 < ppplen 28454, discarding packet
*Dec 5 01:02:00.320: Vi5 UNKNOWN(0xE694): Received short packet, paklen 62 < ppplen 54035, discarding packet
*Dec 5 01:02:00.324: Vi5 UNKNOWN(0xDCD4): Received short packet, paklen 1402 < ppplen 32687, discarding packet
*Dec 5 01:02:00.516: Vi5 UNKNOWN(0xC8E2): Received short packet, paklen 1264 < ppplen 51080, discarding packet
*Dec 5 01:02:00.528: Vi5 UNKNOWN(0xEA52): Received short packet, paklen 54 < ppplen 495, discarding packet
*Dec 5 01:02:00.788: Vi5 UNKNOWN(0xE2B9): Received short packet, paklen 42 < ppplen 60104, discarding packet
*Dec 5 01:02:00.820: Vi5 UNKNOWN(0xBC41): Received short packet, paklen 1264 < ppplen 23135, discarding packet
*Dec 5 01:02:02.724: Vi5 UNKNOWN(0xE675): Received short packet, paklen 578 < ppplen 24574, discarding packet
*Dec 5 01:02:02.880: Vi5 UNKNOWN(0xE06D): Received short packet, paklen 43 < ppplen 24389, discarding packet
*Dec 5 01:02:02.968: Vi5 UNKNOWN(0xE0EF): Received short packet, paklen 42 < ppplen 21007, discarding packet
*Dec 5 01:02:03.820: Vi5 UNKNOWN(0xC62D): Received short packet, paklen 578 < ppplen 30358, discarding packet
*Dec 5 01:02:03.820: Vi5 UNKNOWN(0x80DD): Received short packet, paklen 578 < ppplen 31726, discarding packet
*Dec 5 01:02:04.888: Vi5 UNKNOWN(0x8802): Received short packet, paklen 43 < ppplen 45227, discarding packet
*Dec 5 01:02:05.980: Vi5 UNKNOWN(0xCE4B): Received short packet, paklen 43 < ppplen 14673, discarding packet
*Dec 5 01:02:06.328: Vi5 UNKNOWN(0x90BE): Received short packet, paklen 1402 < ppplen 24659, discarding packet
*Dec 5 01:02:06.876: Vi5 UNKNOWN(0x84AC): Received short packet, paklen 42 < ppplen 58147, discarding packet
*Dec 5 01:02:06.884: Vi5 UNKNOWN(0xECE7): Received short packet, paklen 43 < ppplen 48722, discarding packet
*Dec 5 01:02:06.980: Vi5 UNKNOWN(0x9E5B): Received short packet, paklen 43 < ppplen 26981, discarding packet
*Dec 5 01:02:07.264: Vi5 UNKNOWN(0x9C03): Received short packet, paklen 43 < ppplen 18028, discarding packet
*Dec 5 01:02:07.424: Vi5 UNKNOWN(0xFC37): Received short packet, paklen 1264 < ppplen 17605, discarding packet
*Dec 5 01:02:07.612: Vi5 UNKNOWN(0x9A4E): Received short packet, paklen 43 < ppplen 14089, discarding packet
*Dec 5 01:02:07.980: Vi5 UNKNOWN(0xEE71): Received short packet, paklen 43 < ppplen 10508, discarding packet
*Dec 5 01:02:08.264: Vi5 UNKNOWN(0xD212): Received short packet, paklen 43 < ppplen 22303, discarding packet
*Dec 5 01:02:08.360: Vi5 UNKNOWN(0xA2DC): Received short packet, paklen 43 < ppplen 42415, discarding packet
*Dec 5 01:02:08.612: Vi5 UNKNOWN(0x8A83): Received short packet, paklen 43 < ppplen 5687, discarding packet
*Dec 5 01:02:09.360: Vi5 UNKNOWN(0xF669): Received short packet, paklen 43 < ppplen 4169, discarding packet
*Dec 5 01:02:09.524: Vi5 UNKNOWN(0xEAF2): Received short packet, paklen 50 < ppplen 20402, discarding packet
*Dec 5 01:02:09.528: Vi5 UNKNOWN(0xE087): Received short packet, paklen 50 < ppplen 22405, discarding packet
*Dec 5 01:02:10.408: Vi5 UNKNOWN(0xA6F1): Received short packet, paklen 43 < ppplen 4267, discarding packet
*Dec 5 01:02:11.128: Vi5 UNKNOWN(0xF46D): Received short packet, paklen 1402 < ppplen 45394, discarding packet
*Dec 5 01:02:11.704: Vi5 UNKNOWN(0xCA2F): Received short packet, paklen 43 < ppplen 52865, discarding packet
*Dec 5 01:02:12.520: Vi5 UNKNOWN(0xAA44): Received short packet, paklen 43 < ppplen 22376, discarding packet
*Dec 5 01:02:13.360: Vi5 UNKNOWN(0x807D): Received short packet, paklen 43 < ppplen 2722, discarding packet
*Dec 5 01:02:13.408: Vi5 UNKNOWN(0xF876): Received short packet, paklen 43 < ppplen 2219, discarding packet
*Dec 5 01:02:14.616: Vi5 UNKNOWN(0xDC77): Received short packet, paklen 43 < ppplen 5222, discarding packet
*Dec 5 01:02:15.364: Vi5 UNKNOWN(0xC44C): Received short packet, paklen 43 < ppplen 58431, discarding packet
*Dec 5 01:02:16.932: Vi5 UNKNOWN(0x800C): Received short packet, paklen 50 < ppplen 3408, discarding packet
*Dec 5 01:02:17.292: PPTP tnl 01F66:________: timeout -> echo state change Idle to wt-echorp
*Dec 5 01:02:17.360: PPTP tnl 01F66:________: EchoRP -> echo state change wt-echorp to Idle
I was able to reproduce this several times by streaming youtube videos and downloading large files while on the VPN. The "Received short packet" lines always occur as soon as the VPN begins to hang and my video stops buffering. There doesn't appear to be a lot of documentation on this particular debug error, and I'm not sure where to begin looking. Does anyone have any advice or documentation that may point me in the right direction?
I have a feeling this has something to do with virtual-assembly, but I'm not sure. Thanks for any input!
Throwing packets since 2012
