Posts Tagged ‘Junos’

Yup, they have something similar now, here is the skinny:


archive
path flash1:
maximum 14

Now, before you make a change, issue this command:


configure terminal revert timer <1-120> <--- in minutes

Go ahead and make your changes, if you get disconnected, it will rollback the configuration in the amount of time you selected.

If the configuration works and you want to commit the changes:


configure confirm

That's all folks, a "commit confirmed" for Cisco IOS.


I get this a lot in my field “I cannot ping the server, it must be down or a network issue”; however, I can log in and telnet to the machine and even RDP/SSH into the machine. Why is this? Simple, the machine is not responding to ICMP ECHO REQUESTS which is default behavior for some systems. Windows 7 and Windows server 2008 DO NOT respond to ping by default because their internal firewalls are set to NOT respond to ICMP ECHO REQUESTS. Therefore, the machine could show as DOWN because it doesn’t respond to ping but the machine could actually be alive and on the network.

I personally recommend allowing your machines to respond to ping because there are no benefits to not allowing it other than confusion that could arise from the unexpected. Hiding a PING response doesn’t provide more security because a TCP SYN scan could prove that your machine is alive and well if there are listening ports, among other methods of host discovery.

To put it simple, DO NOT RELY ON PING as a method of testing connectivity only.


Core vs. Edge Routing Topology

There isn’t a lot of talk about this; however, there is a lot of training material that references this debate and makes recommendations for edge based routing. For those not familiar with the topic I am talking about “Campus LANs” and not ISP networks where you essentially have to push routing to the edge for some customers. In my article I am talking about Core vs Edge in the aspect of where we perform all of our routing in a “Campus LAN” Read the rest of this entry »


There are numerous occasions where we would like to utilize a more “human” name to view our physical switchport and router port connections; however, I find that most people don’t maintain these names/descriptions in a proper manner. While this configuration has no bearing on the operation of the switch it will create confusion for those who have to read through the documentation. Read the rest of this entry »


Quote from Junipers facebook:

JUNOS TIP: Suppose you saw that your Alarm LED is red. Issue either the show
system alarm command or the show chassis alarm command.

One reason for chassis alarm is that the management port is not
connected. To clear this alarm, if you are not actually using the management
port, merely execute the following command: root@Junos#set
chassis alarm management-ethernet link-down ignore.

And one reason for the system alarm is that there is no rescue configuration
created. To fix this alarm, merely save a rescue configuration: root@
Junos#run request system configuration rescue save.
Let’s illustrate this:
root@Junos#run request system configuration rescue save


So there is the long standing debate of GUI Vs CLI in both the server and Networking world. There are quite a few angles to argue and I know that in this one single post I am not going to cover 100% of them and I am going to keep emotion out of this and stick to the facts and try to do a “Qualitative review of the two Read the rest of this entry »