I know that your thinking but it’s true. I think it best I only give over limited information and we build on it here.-, if anyone thinks they can.
Issue
Maybe once every three weeks, maybe two days in a row, (could be a good month) we will get a short disruption in internet traffic in the form of DNS what face value, but not all websites. Happens to be the most common and disruptive. OneDrive for example with a DNS error. but other not all are working. another problem site seems to be the bbc.co.uk (UK news/tv/radio). traffic to other sites is fast and works without issue. I think youtube has also been on the list. 3,5,10 minutes later it’s all over.
In the past we have bypassed the Smoothwall and that seems to have worked but it might just be the disconnection / reconnection that fixed it, problem is no time to start testing. Feels like the smoothwall but support have given it a full bill of health and the unit has been upgraded by chance, although the config was exported and imported.
I did put a PC on the network between the Smoothwall and draytek so I could test north of the smoothwall but I can’t remember the result, also its not predictable.
We have looking at this on and off for a LONG time.
Setup
- Largish network, 10 ish vlans, mostly running /20 then a few /24, ACL in play on a fibre HP 3800 switch (gateway)
- 1500 users with half of them having phones and or laptops +
Internet
the 3800 is the end point for all vLANs. This is then routed on a 10.0.99.2/24 via a bridged monitoring appliance called a Smoothwall, then to a Draytek router, Then Juniper ISP router then gone…
Secret
We do have a 2nd site that is routed from the 3800. they sometimes get the same issue as the same time. I wasn’t going to mention as the issue is happening downstream, but incase any spark of some DNS / routing issue back to the 2nd site, i will include here.
If someone picks up this in it’s basic form i will dig a bit deeper and get some screenshots.
I also have snmp