>How to determine number of client can support by using dlink firewall ??
There is no special limitation by clients (it can be by number of ARP on interface), but each DFL has own connections limit and maximum routing speed (VPN speed much less)
Approx. values
- DFL-210/260 - 10000 connections - 80 mbit/sec
- DFL-800/860 - 20000 connections - 150 mbit/sec
- DFL-260E - 25000 connections - 80~150 mbit/sec (by different datasheets)
- DFL-860E - 50000 connections - 150~200 mbit/sec
Also, 2xx models have 3 free physical interfaces, 8xx - 4 + different number of VLANs
So, you need to select device in according with your situation
>what is the difference between normal firewall and E category (ex : DFL-860 & DFL-860E )
Generally, "non E" models are EOL
If to say about difference, 860 has hardware AV/IDS/IPS + 1-year normal subscription, which increase price
860E has hardware AV/IDS/IPS, but no subscription - you can purchase if you need
It covers only 2xx/8xx models - DFL-1600 is old series, DFL-1660 - new
Also, "E" models have new design - build in power supply, port based VLAN function, modern functions like SSL VPN or IPv6
So, "E" models are better than old ones
>What is advanced IPS
Additional signatures
>what's happen to IPS , WCF and AV procedures when trail or linces finished ??
Since 2.25, trial signatures are removing after trial period
But, for licensed (purchased) - it will be kept, but not updated anymore