macOS – SSH Error ‘No Matching Exchange Method Found’
Mar24

macOS – SSH Error ‘No Matching Exchange Method Found’

KB ID 0001245  Problem Note Certified working all the way up to macOS Big Sur version 11.2.3 I thought my RoyalTSX had broken today, I upgraded it a couple of weeks ago, and I upgraded to macOS Catalina 10.15 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...

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Cisco: Getting a SKU (Product ID) From a Serial Number
Apr28

Cisco: Getting a SKU (Product ID) From a Serial Number

KB ID 0001674 Problem I had a situation a couple of weeks ago where I had the serial numbers for a bunch of Cisco switches, I needed to get some extended cover for them, but what I didn’t have were the Cisco SKU (Stock Keeping Unit) codes. Solution You will need to have a Cisco CCO login, once you have that go here > Add devices. Give the device a name, (it does not matter what) > Paste in the serial number > Add. Boom,...

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Configuring Cisco HSRP
Feb08

Configuring Cisco HSRP

KB ID 0000946  Problem Cisco HSRP: Normally your client machines have one route off the network, (their default gateway). But what if that goes down? HSRP aims to solve this problem by assigning a ‘Virtual IP address’ to your default gateway (or default route). So that IP can be shared amongst two or more possible devices (routers, or layer 3 switches). Above, we have a client 192.168.1.10 that has two possible routes off...

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DHCP Scope: Full of BAD_ADDRESS Entries
Feb05

DHCP Scope: Full of BAD_ADDRESS Entries

KB ID 0001651 Problem I had a client machine struggling to get an DHCP address, and when I looked in DHCP the scope it was full of this; BAD_ADDRESS This address Is Already in Use Solution A tour of Google and forums is full of posts by people with this problem, and other than, ‘Oh I looked in the logs and fixed it’ (with no mention of what log, or where this log was), or ‘Yeah I used Wireshark and located a problem...

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Cisco Catalist Upgrading 2900, 5500 and 3700 Stacks
Dec23

Cisco Catalist Upgrading 2900, 5500 and 3700 Stacks

KB ID 0001630 Problem People are often nervous about doing this, I’m not sure why because Cisco have made it painfully simple now. That’s because instead of the old /bin files we used to use, you can now upgrade a switch (or a switch stack) using a .tar file with one command, (and it will also upgrade all the stack members and the firmware on any other network modules you have in the switches at the same time). Yes it does...

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Cisco IOS: Ether-Channel Trunks
Apr08

Cisco IOS: Ether-Channel Trunks

KB ID 0001533 Problem This is a subject that every time I need to create an Ether-Channel I end up checking beforehand, so it’s about time I wrote it up. We are combining two different things, an Ether-channel, (an aggregation of links) and a Trunk (the ability to carry many VLANS). If you are NOT from a Cisco background then you might want to read though the following post first to avoid confusion about the world...

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