I have been through intermittent network down at my workplace. The downtime would take normally abt 5 secs and it would be up again. I have checked the network equipments such as switches, routers, modem (leased line to my site office)and servers, found no fault. My ISP reported they can’t find any downtime on my connections. I’m using netscreen firewall, through logs. I found some kind of portscan, fragroute and few others activity passing through the netscreen. I’ve suspected my network have been attacked either by DDOS. Even I have tried using Tipping point but seems not really solve the problem just minimised the occurences.
I need advice where I could start to curb this from occuring again and what prevention i could do to prevent from any other attack. Any equipment or softwares to recommend.
As I just join this new company which my previous IT guy had left me with no documentation and orientation on the network. I’m still trying to understand the network infrastructure. But short term goal now is to prevent from the intermittent network down.
Please assist me.
