Thursday, November 5, 2015

Changing the case of a Windows hostname

Naming convention is something that I’m very particular about and one thing that has always bugged me is if hostnames are not the same case.  In the Windows world there is no functional difference between upper and lowercase hostname, but it’s still enough to bother me.

To change the case is surprisingly easy.

First we log onto “Active Directory Users and Computers” and enable the “Advanced Features” which lives in the View menu.


Double-click the offending hostname and go to the “Attribute Editor”.  Scroll down to the dNSHostName and change the case.


The change will take effect as soon as you reboot the host in question.

Wednesday, November 4, 2015

Cisco traceroute status codes

Just a quickie.  Cisco routers can give seemingly weird (especially if you’re coming from the Windows world) traceroute outputs.  This is something that I did not see documented in either the CCNA or CCNP training guides.

In Cisco routers, the codes for a traceroute command reply are:
! -- success
* -- time out
N -- network unreachable
H -- host unreachable
P -- protocol unreachable
A -- admin denied
Q -- source quench received (congestion)
? -- unknown (any other ICMP message)

For further reading refer to the IBM AIX documentation – as far as I can make out the AIX codes applies to Linux as well.