FTP URLs including username and password

Just about every time I have to type in an FTP URL that contains both the username and password I have to look up what the syntax is. The syntax is:
  ftp://username:password@hostname/

That syntax is a standard and works in most web browsers, the Cisco CLI and others.

Variables in banners

Sometimes it is handy to display the name of the device, the line number you are connected to or other details about a device in the banner. A complete list of the variables (and which banners they can be used in) is available in the Cisco document Slip-PPP and Banner Tokens.
I thought it would be handy to use those tokens in the name of the file for the archive command.... unfortunately it doesn't work. If you use:
archive
   log config
      hidekeys
   path tftp://192.168.1.1/$(hostname)
   write-memory
   time-period 86400

All you end up with is a file called $(hostname)-0 on your tftp server. Hopefully it will be there in a future release.

MPLS Fundamentals

I've finally finished reading and noting the CiscoPress MPLS Fundamentals book. It's only appropriate that I give my thoughts on the book. I was hoping it would be a bit like the Routing TCP/IP book - an easy read which slowly builds your knowledge until you look back and say "Oh my gawd how did I learn all that?". Well it was nothing like that. Some chapters were really "crunchy" full of facts and not enough words to make it clear or easy to read. Other chapters were just plain repetitive (the QoS one for example). I found it a little annoying how it introduced subjects. Often there would be two alternatives presented in a reasonable amount of depth followed up by a paragraph saying... "Cisco implemented option 1". There was also some plain bad editing - at least a few places where the example did not marry up with the text around it, and some where they talk about some numbered items and refer to one that doesn't exist in their list (ie they'd have a list of 4 items and refer to item 5).

Even after all of that I'd have to say I don't regret getting the book. It did cover most of the topics that are in the CCIP MPLS outline to a reasonable depth and covered a few extras that are useful. There were a few chapters that I could have skipped - but I read them anyway because the CCIP MPLS outline and the associated course differ so you can't be too sure what really is going to be on the exam. My recommendation would be to read the MPLS Fundamentals book cover to cover before you start writing notes. Then start again from page 1.

There is still a bit of a gap betweeen the book and the exam outline, so I am going to do a little more reading (not sure if I will grab another book or hit the DocCD and Cisco site). Either way I think I have about two weeks before I'll hit the exam - I'd like a week of solid GNS3 work at night as well as a while to go through my notes and flesh out the bits that the Fundamentals book didn't cover.

MPLS QoS

I'm about 80% of the way through the book. My last week has been a study disaster. I've been busy at work and coming home feeling very flat and unmotivated. Luckily next week I should be doing some MPLS proof of concept and design work. This should mean I get to tinker with some MPLS VPN and QoS at the very least. Hopefully I can justify a little AToM and VPLS as well (we will eventually need to integrate one or both into our network).

MPLS TE

I'm 2/3 of the way through the MPLS Fundamentals book now. Working through MPLS TE was a bit wierd. A lot of lead up and then a very short bit on how to actually get the traffic into the tunnels - I would have thought it was more logical to lay the chapter out the other way. I'm getting a bit impatient with the book. I'm planning on skimming through the rest of it and cherry picking what I think is relevant. It's looking like I might not do the exam this month unless I really get stuck into it now. Usually I would have finished writing my notes and done a reasonable amount of work in GNS3 by now. With the Cisco Secondchance promotion running at the moment I might just book the exam for the 31st and power through and see how I go.

Using screen to view another ssh session

Say you ssh into a host and another person is using ssh to connect to that same host. You can connect to the other session using screen

To attach to a screen session that is already running use screen -x

SSH port forwarding

Today I had a Unix box inside my network that I needed to allow a remote party to connect to. I didn't want to tinker with the firewall rules, so here is what I did.
ssh -R server:2222:localhost:22 username@server

What it is saying is redirect port 2222 on the server named server to port 22 on the localhost. The username@server is used to initiate the remote connection to the server that you want to do the redirection for. So to connect to your host the other party needs to ssh to the server and then ssh to localhost on that server using port 2222.

If you want to set up the port redirection from the server end you can use a -P instead of a -R.