My EtherealMind» IOS

Basics: Cisco IOS Native VLANs

Greg Ferro — Thu, 09 Jun 2011 18:41:11 +0000

Cisco IOS and Native VLANs - some brief notes to myself.

Those Non-IOS Files on the Flash. Are They Useful ?

Greg Ferro — Wed, 08 Jun 2011 18:15:36 +0000

When you first receive a router from a Cisco warehouse, it comes with a complete collection of IOS add ons. A common question is whether these files are used for anything ?

IOS Memory Tables Removed From Documentation

Greg Ferro — Sat, 28 May 2011 15:01:51 +0000

From IOS 15.1M&T release notes at http://www.cisco.com/en/US/docs/ios/15_1/release/notes/151TFEAT.html Memory Recommendations The memory recommendation tables have been removed from the Cisco IOS Release 15.1M&T release notes to improve the usability of the release notes documentation. The memory recommendations that were provided by these tables are available through Cisco Feature Navigator. So the only way to check the [...]

Show Ip Eigrp Topology All

Greg Ferro — Sun, 22 May 2011 13:44:13 +0000

Once upon a time the command was "show ip eigrp topology" to show EIGRP topology, now it's "show ip eigrp topology all" and the old command show only Feasible Successors.

OSX: Shortcuts for Subnet Masks With TextExpander

Greg Ferro — Wed, 09 Mar 2011 17:46:26 +0000

I'm always looking for ways to improve my writing speed and accuracy. One way is to use specific keyboard shortcuts for tasks that are repetitive and prone to inaccuracy. So, using Cmd-C / Cmd-V for for Copy and Paste makes a whole load of good sense as it's faster & more accurate than using the mouse to click through multiple menus, and put the cursor where it needs to be. However, keyboard shortcuts are kind of limited. A more flexible approach is to use a program that can substitute short sets of text into much longer pieces. To do this, I use a program called TextExpander to keep a library of 'snippets' for expansion into a range of useful actions. For example, I have a text snippet etmd and whenever I type these four letters, it is automatically expanded to EtherealMind. The possibilities are endless, and I'm hoping to share a few different ideas and get feedback from you to help me build my collection of useful shortcuts.

Cisco IP Traceroute Characters

Greg Ferro — Fri, 25 Feb 2011 17:25:31 +0000

Note to self about Cisco Traceroute characters and what they mean. Directly from the Cisco IOS user documentation.

Cisco IOS Emulator Petition – Reloaded

Greg Ferro — Fri, 11 Feb 2011 19:01:08 +0000

Due to popular demand I have restarted the IOS Petition. The last petition got to nearly 1200 signatures before something caused it to crash. Either way, it's time to signal to Cisco that we remain serious and committed to getting proper access to testing and learning emulation software.

Remember, if you are using Dynamips you won't be able to test IOS Version 15.0. What will you do when they come for you ?

After all, Cisco's share price dropped 12% this week, maybe they will be listening a bit more closely to their customers instead of ignoring us.

Head over to the petition and sign up. The system has protection against blind and double voting - I've activated the email confirmation. I won't abuse your email address but you will need to use a genuine email or your vote doesn't count.

Cisco IOS Petition - Reloaded

Cisco IOS CLI Shortcuts

Greg Ferro — Sun, 06 Feb 2011 18:02:01 +0000

Mostly for my own reference. I really need to practice using the Delete Buffer commands and Ctrl-R Refesh as part of my muscle memory.

Three Ways to Fix the Cisco IOS Translating “Xyz” Domain Server

Greg Ferro — Thu, 27 Jan 2011 12:07:55 +0000

Fixing the Cisco IOS Domain Lookup - three different options.

Licensing Tips for 3750 Stacks

John McManus — Tue, 11 Jan 2011 22:23:46 +0000

Recently I had to upgrade some 3750-x Stacks to Advanced Services and the Cisco documentation was a bit short of advice, and certainly not all in the one place. So here is a quick run down of some key steps.

Cisco IOS SX Storm Control

Greg Ferro — Tue, 11 Jan 2011 13:31:38 +0000

Blurt on Cisco Storm Control

Key Change for Cisco IOS 15 – Feature Licensing and How We Work.

Greg Ferro — Wed, 13 Jan 2010 19:03:32 +0000

Welcome to IOS 15, Feature licensing and complicated maintenance procedures....

Cisco Announces EOS and EOL Cisco IOS Software Release 12.4

Greg Ferro — Wed, 13 Jan 2010 18:44:05 +0000

Cisco announces the End of Life and End of Support dates for 12.4. Before IOS 15.0 is even warming up, the previous version of 12.4 is already on life support.

The Poor Man’s IOS Traffic Generator

Greg Ferro — Sat, 19 Sep 2009 15:30:38 +0000

This is a feature that I used to use years ago, but had forgotten about. For some reason, I remembered it today and it is still as useful as it ever was. Read on...

IOS CLI: Show Run Linenum

Greg Ferro — Wed, 09 Sep 2009 20:00:02 +0000

You probably know this one already, but I have been typing ìwr tî for a long time and never stopped to look. Puts a line number at the side of the config so you can say to the person on the other end of the phone, see line 10………. r2#sh run linenum Building configuration… Current [...]

Cisco IOS Order of Operation – Updated, Again

Greg Ferro — Wed, 09 Sep 2009 19:00:52 +0000

I often need to refer to the IOS order of operation when I start stacking multiple functions in an IOS configuration.

Changing the Break Character in Cisco IOS

Greg Ferro — Fri, 21 Aug 2009 07:08:44 +0000

Does pressing "Ctrl-Shift-6 & x" bother you ? It bugs the hell the out of me.

IOS: Setting the TCP Timeout on IOS

Greg Ferro — Thu, 14 Aug 2008 17:20:28 +0000

One of my favourite default commands on IOS is "ip tcp synwait 5". Lets look into this command and why you might like to use it as well.

IOS: Enable and …. Disable ?

Greg Ferro — Sun, 20 Jul 2008 06:59:00 +0000

All these years, and I didn’t realise the opposite of the enable, was disable. Router> Router>enable Router#disable Router> Does this means that I am ‘dissing’ my router ?

IOS: ROMMON on the C6500/Sup720 – Lesson Learned

Greg Ferro — Sat, 28 Jun 2008 19:54:28 +0000

Recently, one of my Supervisor 720 goes into a permanent reboot cycle. I was able to break it into ROMMON mode, but I couldn’t get it to ‘stick’ the boot settings. Finally…. Finally, one of the other guys came and looked over my shoulder and pointed out that I was making two mistakes. Here is [...]

IOS: Reverse SSH Console Access – Part 2

Greg Ferro — Wed, 25 Jun 2008 06:50:59 +0000

Following my original post about configuring Reverse SSH on a Cisco console server, I wanted to make some followup to extend the usage.

Configuring Windows 2003 / XP SP2 to Use IOS NTP Server

Greg Ferro — Tue, 10 Jun 2008 06:31:51 +0000

In certain networks, it is difficult to get the time on your servers to be exactly the same as the NTP time on your network equipment. In this case, you want to force the Windows servers to use the same NTP Network time source as your routers and switches. But Microsoft Windows doesn’t understand NTP [...]

IOS:Open Source Lab DNS and IP Addressing

Greg Ferro — Mon, 02 Jun 2008 06:57:01 +0000

A number of Cisco Bloggers have talked about making labs available for others to use. However, part of what will be needed is some conventions to make these labs work for the largest number of people. Following Ivan Pepelnjak posting on Private Domain Names, and an earlier posting that I made on Reserved IP Address [...]

IOS: Reverse SSH Console Access

Greg Ferro — Thu, 29 May 2008 20:13:20 +0000

I recently needed to secure the reverse console access using Cisco IOS router. Now for many years, we have been doing this over telnet and the configuration has been straightforward. But configuring it to support SSH instead of telnet is a little bit different, awkward in fact.

Ip Tcp Timestamp

Greg Ferro — Mon, 14 Apr 2008 06:41:18 +0000

ip tcp timestamp I have seen this command a few times, today I am going to look into it and see what it does. Also, this is probably a classic CCIE lab gotcha. From the Cisco documentation: The TCP time-stamp option provides better TCP round-trip time measurements. Because the time stamps are always sent and [...]