Extreme Networks X695 – 40Gbit, 100Gbit QSFP(28) Ports and Port Paritioning Explained

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The Extreme Networks X695 switches have a special port configuration arrangement that you need to be aware of when configuring the switch for use. Verified on: ExtremeXOS version 30.6.1.11 30.6.1.11-patch1-4 by release-manager on Tue Jul 7 10:36:05 EDT 2020 The switch supports the following: 48 x SFP28 1Gb/10Gb/25Gb Ports 8 x QSFP28 40Gb/100Gb Ports Up … Read more

Extreme Networks Switch – “Error: VLAN Default cannot be disabled because it is configured for an L2 Protocol.”

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It is pretty standard practice to disable the default VLAN and renumber its tag ID for security reasons, from version 22.4 and above we often go this issue when performing these basic commands: We’d get the error as below. In our case we don’t want to run STP (Spanning Tree Protocol) because we’re using either … Read more

Monitor Rx and Tx Errors on Extreme Networks Switches via SNMP Query (using NagiosXI)

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It is helpful to monitor the RxErrors and TxErrors on ports on Extreme Networks switches to get a heads up on any issues before they begin to impact service. The Extreme Networks MIB can be downloaded from the Extreme Networks support portal to assist you in finding the relevant SNMP OIDs, the below is an … Read more

Active Directory Certificate Services (ADCS) PKI Domain Admin Vulnerability

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Microsoft have published a vulnerability: https://msrc.microsoft.com/update-guide/vulnerability/ADV210003 which allows an attacker to use the NTLM authentications to begin an attack chain to make an unauthenticated NTLM connection that is then relayed to allow a connection to the Active Directory Certificate Services (ADCS), this assuming the auto-enrollment is enabled means that an attacker can make a request … Read more

Dell Openmanage DNS Records for Server Initiated Discovery (with Microsoft DNS)

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OpenManage Enterprise version 3.4 allows automatic discovery of servers that have iDRAC firmware version 4.00.00.00 or later. The appliance can be configured to allow these servers to automatically locate the console by querying the DNS and initiate their discovery. The instructions (and this) give the use of the TUI or manual creation for Dell Openmanage … Read more

VMware Datastore Naming

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How do you name your VMware datastores? Its an interesting question, how much information do you want to convey? Do you want to give a system administrator some idea of the data protection provided by the underlying storage perhaps? Or some idea of the location? There’s lots to think about, but also simplicity can be … Read more

Robocopy to Copy Files with Permissions and Ownership

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If you need to copy files from one storage location to another Robocopy is a great tool, but like every great tool it comes with loads of options. In this scenario I was needing to copy a directory structure (and all the files) from one location to another but preserving all the permissions, ownership and … Read more

Putty.exe – “Couldn’t agree a key exchange algorithm”

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I had this issue today, on a host that had recently had a software upgrade. Problem: A host to which I was connecting with SSH gave this error: “Couldn’t agree a key exchange algorithm (available: Curve25519-sha256@libssh.org, ECDH-sha2-nistp521, ECDH-sha2-nistp384, ECDH-sha2-nistp256)”. Solution: In my case I updated to a later release of Putty.exe and the issue was resolved. … Read more

Leaky Print Spooler Vulnerability (CVE-2021-1675)

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So it appears that there is a vulnerability identified in Microsoft Windows machines running Active Directory, this is covered on the Register: https://www.theregister.com/2021/06/30/windows_print_spool_vuln_rce/ Until you patch this you can just disable the “Printer Spooler” service on your Domain Controllers and well to be honest you don’t need this running on the Domain Controller anyway. Edit: … Read more