Switches and routers

September 24, 2018

ProCurve SSH – no matching cipher found

I recently ran into a strange problem where I suddenly couldn’t SSH to any of our HPE ProCurve 2800 series (2824, 2848) devices from either macOS or Linux. I’m still not really sure what started this as OpenSSH definitely hasn’t been updated recently on the Linux client device at the very least, so I don’t see any reason for the...

HP ProCurve Comments: 0

November 12, 2015

Cumulus attacks on Juniper (again)

I have a lot of time for Cumulus Networks – I think they’re doing some very cool and unique things with their Cumulus Linux operating system for switches and they genuinely have something different to offer, but when they publish blog posts like their one today (https://cumulusnetworks.com/blog/junipers-second-run-up-the-open-networking-mountain/) I lose a lot of respect for them. This seems to be nothing...

General/Juniper Comments: 0

May 2, 2012

4GB of RAM on a Juniper J-Series router (J6350)

Officially the Juniper J-series routers such as the J6350 only supports a maximum 2GB of RAM. The J6350 comes with 1GB of RAM installed and if you want to add more then you have to buy your RAM from Juniper at inflated prices, however as the J-series are standard x86 machines with Netburst era Celeron and Pentium 4 processors you...

Juniper Comments: 0

April 28, 2011

RouterOS slow learning BGP routes with Winbox open

After banging my head against a wall waiting for a RouterOS powered router to re-learn the 330,000 routes that currently make up the global routing table, I was surprised to find that seemingly Winbox slows the learning of BGP routes to a crawl. Closing Winbox allowed the router to process the entire global routing table in the normal minute or...

Mikrotik RouterOS Comments: 0

November 3, 2010

Cisco DHCP snooping with a Cisco DHCP relay (ip helper) and DHCP option-82

By default, the Cisco DHCP snooping code on the Cisco Catalyst switches inserts option-82 into the DHCP packet but sets giaddr to 0.0.0.0, which causes the Cisco DHCP relay (ip helper) to drop all DHCP packets from a Cisco switch configured with DHCP snooping. To work around this, you can either disable the insertion of Option-82 on the switch performing...

Cisco Comments: 0

July 4, 2010

SSH on a HP ProCurve

By default HP ProCurve devices (like most switches) use telnet and TFTP (Trivial File Transfer Protocol) for management access, firmware upgrades and config backups. As these are both unencrypted protocols, it is a good idea to switch to using SSH and SCP/SFTP in order to secure your management access and all important configuration, which you can do with the following...

HP ProCurve Comments: 0

July 3, 2010

Changing the MAC address of a VLAN interface in Mikrotik RouterOS

Do you want to change the MAC address of a VLAN interface in Mikrotik RouterOS? Are you baffled by the fact that although the VLAN interface has a MAC address property inherited from the parent Ethernet interface, it isn’t editable? Well, you’re in luck, it isn’t actually impossible to give your VLAN interface a different MAC address to it’s parent...

Mikrotik RouterOS Comment: 1

January 20, 2010

RouterOS v4.x and BGP

Just a quick heads up for those using upgrading from RouterOS 3.x to 4.x and using BGP to announce a default route to any of your peers; you need to set “default-originate” to “always” or “if-installed” for each peer you have configured in RouterOS if want to announce the default route to. This setting is off by default in v4.x...

Mikrotik RouterOS Comments: 0

August 3, 2008

On the warpath

Hey, guess what? In typical Edward style, it has been ages since I updated this thing and I still haven’t got the site working fully or using a custom skin. I have an excuse… I am busy/lazy (take your pick!) 😉 I got back from going to see “The Dark Night” a couple of hours ago. It’s a bloody good...

General/Mikrotik RouterOS Comments: 0

Spheron1

Category: Switches and routers