A client required isolated networks for factory hardware but their infrastructure, many basic NetGear switches, did not support VLAN separation (my original hope was to use the DrayTek default gateway for inter-VLAN routing). This required some 'thinking outside of the box' and resulted in a design that made use of a DrayTek to isolate the … Continue reading WDS Transparent Mode, DrayTek Inter-LAN Firewalls and some interesting observations!
With a client going for an ISO standard which dictates stringent controls over both the external and the internal network resources I decided to put in some additional controls to ensure confidentiality, integrity and availability of the internal network. As the client uses Cisco hardware on premise, this consisted of a trio of additional measures … Continue reading DHCP Snooping, Dynamic ARP Inspection and IP Source Guard
So we all know backups of servers are pretty important, but what about the network fabric everything runs on? For most readers of this blog we’ve moved away from ‘dumb’ switches that you can connect to the LAN with no concerns about the underlying setup toward more intelligent switches that now perform port security, VLAN isolation … Continue reading Automated Configuration Backup of Cisco Devices
Continuing to build on earlier posts where we setup 802.1x to authenticate users and place them in predefined VLANs, then extended this to dynamically assign the VLAN, this post will look at what to do for devices that don't speak 802.1x such as printers etc. While there is a guest VLAN command for dot1x we could use … Continue reading 802.1x MAC Authentication Bypass (MAB) to an NPS Server
Recently a client approached me as they regularly had interruptions on their network which was starting to frustrate them. After a short period of monitoring via PRTG it was clear they were suffering periodic bouts of packet loss on the LAN which seemed to peak during working hours and the slow downs were experienced by … Continue reading Spamming Spanning-Tree