Category: show filters
After I've published the Tcl script that displays the interface IP parameters in a formatted table, cos quickly pointed out a bug: I've expected the IP addresses in the address mask format. In the meantime, I've figured out the root cause of the problem (our remote labs are set to display IP masks in decimal format for compatibility reasons) and fixed the Tcl script. It temporarily sets the terminal ip netmask-format to bit-count before executing the show command. The new script recognizes three parameters:
- active: display only interfaces that are up/up;
- configured: display only interfaces with configured IP addresses (unnumbered interfaces using IP address of an interface without one count as configured since IOS reports their IP address as 0.0.0.0).
- address: displays IP address of the unnumbered interface, not the interface that it's borrowing the address from.
To use it, download it and store it into the flash memory of your router. Configure alias exec ipconfig tclsh flash:ipInterfaces.tcl and you can use ipconfig or ipconfig active to display interface IP addresses.
If you've deployed EIGRP stub routers in your network, you'd probably like to know which neighbors of a particular router are stub routers. Unfortunately, the only command to display a neighbor's stub status is the show ip eigrp neighbor detail command, which is a bit too verbose for what we need.
event manager applet SaveInterfaceStatusNotes:
event timer watchdog name SaveIfStat time 60
action 1.0 cli command "show ip interface brief | redirect ftp://username@password:host/path"
action 2.0 syslog msg "Interface status saved"
- The timer watchdog EEM event defines a recurring event triggered every X seconds.
- Output of a show command can be redirected only to a TFTP or FTP server, redirection to a web (HTTP) server does not work yet.
- The syslog action is configured for debugging purposes only and can be removed in production environment.
- More complex functionality (for example, sending show command output in an email) can be implemented with help of Tcl EEM policies
In this month's IP Corner article, Enhance the IOS User Interface, I'm describing how to use simple filters provided by the Cisco IOS to pick only the information you need from the printouts, as well as how to generate tailored printouts (even combining outputs from multiple show commands) with Tcl shell introduced in IOS release 12.3(2)T.
The show output can be redirected to a local filename (in flash, on usb token or even in NVRAM) or sent to a remote server (currently only FTP and TFTP servers are supported). For example, the show ip interface brief | redirect ftp://student:[email protected]/ifstatus command will store the current interface status to an FTP server.
Note: the append (or tee /append) operation only works on destinations that support the file append operation: class-C flash file systems, local disks, USB tokens and NVRAM.