Cisco IOS – How To Find VLAN IPs (SVI’s)
Nov16

Cisco IOS – How To Find VLAN IPs (SVI’s)

KB ID 0001258 Dtd¬†16/11/16 Problem If you have a complicated network, you can spend more time finding out how it’s configured, than actually doing any work on it! Today I had a client that needed some changes made on their LAN, I knew their name, and their network address, and common sense told me which of the core switches they were connected to. Solution A quick search on the client name told me what VRF they were in, and what...

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Cisco IOS ‘Crypto’ Unrecognized Command?
Oct15

Cisco IOS ‘Crypto’ Unrecognized Command?

KB ID 0001246 Dtd 15/10/16 Problem I was working on a Cisco 3750-G last week, and I was in the process of setting up SSH access. When I went to generate the crypto key and enable SSH, It fired an error at me. In fact it wouldn’t execute any crypto commands; Core-SW(config)#crypto ? % Unrecognized command ¬† Now I have seen this before, (but not for a while). You need to be running a K9 version of the code. A quick ‘show...

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MAC OSX – SSH Error ‘No Matching Exchange Method Found’
Oct13

MAC OSX – SSH Error ‘No Matching Exchange Method Found’

KB ID 0001245  Problem I thought my RoyalTSX had broken today, I upgraded it a couple of weeks ago, and I upgraded to macOS Sierra version 10.12 the other day. After this, all my SSH sessions refused to connect with this error;   Unable to negotiate with x.x.x.x port 22: no matching key exchange found. Their offer diffie-hellman-group1-sha1 Note: You may also see the following error; Unable to negotiate with x.x.x.x port 22: no...

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Cisco Stacking 3750 Switches
Jun16

Cisco Stacking 3750 Switches

KB ID 0001205 Dtd 17/06/16ProblemYou can stack Cisco 3750-X Switches in groups of up to 9 switches, and they can then be managed as one switch. Here I’ve got 2 switches.¬†SolutionRemoving 3750-X Switches Stack ConfigurationOne of my switches had already been in a stack, so I needed to remove its stack configuration. It thought it was switch 4 in the stack so I issued the following commands; Switch(config)# no switch 4 provision...

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Device Boots to ROMMON (Cisco ASA)
Jun01

Device Boots to ROMMON (Cisco ASA)

KB ID 0001199 Dtd 01/06/16 Problem After recently picking up some second hand ASA5512-X firewalls, I went to run them up, and make sure they were ok, however on boot up they went straight to ROMMON like so; Use ? for help. rommon #0> Now I know what ROMMON is, it’s the base operating system of the device, its job is a bit like the BIOS on a PC, it locates and loads the operating system. The only time you should ever see a...

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Microsoft – NDES Site Shows ‘HTTP Error 500.0 – Internal Server Error’
May06

Microsoft – NDES Site Shows ‘HTTP Error 500.0 – Internal Server Error’

KB ID 0001181 Dtd 06/05/16ProblemI was doing some testing for a client this week, a while ago I had deployed a three tier PKI solution for them, and as part of the rollout we deployed NDES for their network devices, (they were going to use certificates to secure site to site VPNs). The client was concerned, and wanted the auto renewal process testing. This could not be done on the live system. So myself and a colleague went to the...

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