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...
Using OSPF over DMVPN
KB ID 0001151 Dtd 03/02/16 Problem This article is a supplement to the earlier one on Setting Up DMVPN. It covers how to use OSPF over the top of DMVPN. This is the topology I’m going to use; As I’ve said (above) this is not a run though on setting up DMVPN, but if you want to spin it up in GNS3, or on the test bench, here’s the DMVPN config; Hub Site configure terminal interface Tunnel10 ip address 192.168.254.1...
Cisco Catalyst Switches – Adding Licenses
KB ID 0001012 Problem I had a load of Cisco Catalyst 3560 switches that needed ‘ipbase’ licenses adding to them today. I’ve messed about with plenty of ASA license upgrades before, but not switches. Solution 1. First thing you need is a Cisco PAK, this may be in an email or turn up in a cardboard envelope. 2. Go to http://www.cisco.com/go/license and log in (if you don’t already have a Cisco CCO account you...
NDES – Fails to Issue Certificates (Signature Algorithm)
KB ID 0001021 Problem I was trying to enroll some ASA firewalls to NDES to get some certificates. Each time the process failed with the following error. % Error in receiving Certificate Authority certificate: status = FAIL, cert length = 0 That’s a pretty generic error, and does not give me a lot to go on. So I thought I would try from another network device, (a Cisco Catalyst switch). It’s a little easier to...
GNS3 – Error ‘ghostsize is to small for device’
KB ID 0000935 Problem While doing a quick lab in GNS3, I tried to add NAT to a router, and it fell over with the following error; R3(config-if)#ip nat outside % NBAR ERROR: parsing stopped % NBAR Error : Activation failed due to insufficient dynamic memory % NBAR Error: Stile could not add protocol node %NAT: Error activating CNBAR on the interface FastEthernet0/0 R3(config-if)# *Mar 1 00:01:11.655: %SYS-2-MALLOCFAIL: Memory...