If you use broadcast/multicast storm protection on cisco switches, make sure the other network gear supports it or make sure you don’t use it on trunk links. ick.
Don’t use any cisco protocols that run over LLDP (CDP, VTP, DTP, etc). Enno and Daniel in their learning of fuzzing found that these protocols generally have crappy implementations. Love live the germans btw.
Bring a router/firewall with wireless preconfigured, otherwise you delay the non-network groups from making progress while you configure the network.
Check last years configuration for monitor ports.
Aruba gear used as a switch is not ideal, like it only supports one span/monitor port.
Monowall sucks for not having a shell.
Pfsense doesn’t support vlan tagging on some soekris gear (5501) and thus sucks.
When you have security vendors doing vulnerability scanning, make sure your firewall has a huge ( > 50,000) state table.
Due to hardware/cabling issues, having multiple dns/dhcp servers is ideal.
A /24 is far too small of an address space for a security conference. Especially if someone configures it to only serve 100 address via DHCP.
Don’t use vlans over 1000, especially on cisco gear. it’s confusing and not necessary. if you do, don’t use 1000-1004 or so, and pay a keen attention to spanning tree (‘show int
Sometimes gear has to have a vlan configured before it will trunk it (see above command)