IPSec VPN Traffic Dropping Regularly


I'm writing this here with the hope that someone at Optus will read it and forward it to one of their network engineers. If you are from Optus and are reading this please feel free to contact me - you should be able to get my contact details using my username.


I have two site to site IPSec VPN connections configured, each to unrelated sites. Everything had been working perfectly for months, until sometime between the 31st of August 2017 and the 1st of September 2017 (that's a two day window). Now I'm having significant VPN connection issues to both sites (recall the remote sites are completely unrelated - they are even in different continents). Configurations have not changed at any endpoint. I've looked into it and there appears to be a high rate (~25-50%) of packet drops between the endpoints. Looks to be more of an issue of the packets leaving my endpoint... I think I'm receiving remote packets 'reliably'. Note that not all packets are dropped, so sometimes packets from my endpoint are making it to the other side. After several attempts the tunnel does come up, but due to the high drop rate the connection is painfully laggy and drops out withint minutes due to dead peer detection (DPD).


This problem if very similar to the one posted here:


Please feel free to review the above post.


I'm an Optus business customer (with a different account, which I'm happy to discuss with an Optus representative). I've tried calling technical support, but couldn't get through. It is very important that this issue is resolved before Monday.


Any help would be greatly appreciated.


Re: IPSec VPN Traffic Dropping Regularly




Could be due to the damage to undersea cable caused by the typhoon in Hong Kong.  See previouspost:


I’m a Yes Crowd Champion (not an Optus employee). I share my knowledge on Yes Crowd on a voluntary basis. If I answered your question, please mark it as a Accepted Solution. If I helped you out, hit that Kudos button Smiley Happy

Re: IPSec VPN Traffic Dropping Regularly


Thanks for that Dave. That could be causing the issue.


Adding further information, the remote sites are South Korea and Taiwan.

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