Cisco IOS – DHCP Helper (DHCP Relay) – IP-Helper Setup
KB ID 0001168 Problem Cisco documentation calls this a ‘DHCP Relay’, and uses the command IP-Helper, and I usually call this DHCP Helper, just to confuse everyone. To be fair the term DHCP Relay is an industry standard, it’s not particular to Cisco (as you will see later when I Wireshark the traffic). So If you are reading this you have a DHCP server and you want to use it to lease addresses to clients that are on a...
HP Networking – Tracing Networks and Locating IP addresses
KB ID 0001110 After not touching one for a couple of years, I was back on HP switches recently, and I had to map out a clients switches. Now I could have used some software, but they didn’t have SNMP enabled so, I had to ‘re acquaint’ myself with LLDP. For a basic LLDP View of attached devices. HP-Switch-1# show lldp info remote-device LLDP Remote Devices Information LocalPort | ChassisId PortId PortDescr SysName...
GNS3 Cannot Connect Network Interfaces when running on VMware vSphere
KB ID 0000671 Problem I have plenty of real ASA firewalls to play with, but it’s getting round to re-certification time, so for ease I thought I’d run up a Virtual ASA on my vSphere 5 box just for testing and breaking. However no matter what type of Virtual Network adaptor I used (vmxnet3, e1000, etc) I could not connect to the virtual firewall. Solution 1. Firstly make sure you actually have an IP address in the correct...
Update Cisco ASA – Directly from Cisco (via ASDM)
KB ID 0000636 Problem Warning: Before upgrading/updating the ASA to version 8.3 (or Higher) Check to see if you have the correct amount of RAM in the firewall (“show version” command will tell you). This is VERYIMPORTANT if your ASA was shipped before February 2010. See the link below for more information. ASA – Memory Error (Post upgrade to version 8.3) Warning 2: Be aware, if you are upgrading to an OS of...
Cisco ASA 5500 – Throttling (Rate Limiting) Traffic
KB ID 0001001 Problem If you have one client that’s taking all your bandwidth, or a server that’s getting a lot of connections from external IP addresses, and that’s causing you performance problems, you can ‘throttle’ traffic from/to that client by ‘policing’ its traffic. Solution To demonstrate, I have a 30Mb connection at home, when I run a test on the download connection speed from my...