The ramblings of a computer geek
Very occasionally a QSFP+ port might not be the correct form factor, what if you have a switch with only QSFP+ ports e.g. an Extreme Networks X770 but you need to connect up a device with an SFP+ port. Well, although you’ll be wasting a QSFP+ port this may help you. Extreme Networks provide what … Read more
The QSFP+ or QSFP28 ports of the Extreme Networks switches can be partitioned, what this means is you can make a 40Gbit QSFP+ port appear as 4 x 10Gbit SFP+ ports, however you’re require a suitable QSFP+ module for example with MTP port and a fan-out cable to split that MTP into 4 x LC … Read more
The OSI Model (Open Systems Interconnection) model is a set of rules and requirements to model and conceptualise the communication between two (network) systems. Yes, its theory, but in computing and networking it can be useful to use as a basic guide when troubleshooting. It helps you to rule-in or rule-out where a problem might … Read more
A fairly simple approach to providing uplink resilience. There are methods like EAPS or MLAG to give you uplink resilience, but sometimes you just need something simple. A redundant physical (or “Redundant Phy”) is essentially two uplinks to upstream switches and to avoid a loop, the downstream switch (i.e. the one with the redundant phy … Read more
The 5520-VIM-4YE, this has 4 x SFP28 ports 10/25. You can use 10Gbit or 25Gbit speeds on these ports. On an Extreme 5520 Universal hardware switch this will be ports 57-60 (on 48port model) or 33-36 (on a 24 port model) If you want to use 4 x SFP+ modules running at 10Gbit, you need … Read more
Emails crossing the internet use secure connections encrypted using Transport Layer Security (TLS). However, there remain vulnerabilities in this method of protecting the confidentiality of emails, whereby a person-in-the-middle can trick incoming connections to send to another server and/or send information in the clear. MTA-STS is a standard designed to address these vulnerabilities and is … Read more
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
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
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
If you try to monitor a cloudflare fronted website with NagiosXI check_http you may get this: After much fiddling found that if you formulate the check string as: You’ll get a result like this, which is what we want! You need to use this: Enable SSL/TLS hostname extension support (SNI) The SNI is Server Name … Read more