Category Archives: Template

Posts that contain a template for certain configuration tools, firewall, or whatever.

MRTG/Routers2: Counting Traceroute Hops

I was interested in generating graphs within the MRTG/Routers2 monitoring system that display the number of hops for an IP connection through the Internet. In my opinion its interesting to see the different routing run times/hop counts e.g. for remote offices that are connected via dynamic ISP connections such as DSL. Therefore, I wrote a small script that executes a traceroute command which can be called from MRTG.

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MRTG/Routers2: Measuring Ping Times

MRTG can also evaluate values from external scripts such as the “mrtg-ping-probe” program which returns the round-trip time from the initiated ping command to the specified destination host. With an additional GraphStyle called “range” from Routers2, these ping times can be displayed in the monitoring system. This graph style shows the “min” and “max” RTT in one vertical line instead of two independent lines.

Since there is not much to say about this process, I will only paste my MRTG/Routers2 config for mrtg-ping-probe and will show a few example graphs here.

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IPsec Site-to-Site VPN Palo Alto <-> AVM FRITZ!Box

Wer im Büro auf eine Palo Alto Networks Firewall setzt und von zu Hause hinter seiner FRITZ!Box per VPN im Büro arbeiten möchte, der muss die richtigen Einstellungen auf beiden Geräten finden. Genau das habe ich getan und stelle hier die entsprechenden Details online. Viel Spaß dabei. ;)

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IPsec Site-to-Site VPN Juniper ScreenOS <-> AVM FRITZ!Box

Hier kommen die Einstellungen die nötig sind, um ein Site-to-Site VPN zwischen einer AVM FRITZ!Box und einer Juniper ScreenOS Firewall herzustellen. Neben einigen Anleitungen im Netz habe ich selber ein paar Einstellungen getestet, um eine möglichst detaillierte *.cfg Datei zu haben. Außerdem ist erfreulicherweise anzumerken, dass die Juniper auch ein statisches VPN zu einer dynamischen Adresse erlaubt und somit sogar beide Seite einen Verbindungsaufbau initiieren können. Mit dem VPN Monitor von Juniper wird der Tunnel konstant “up” gehalten.

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Small “What-is-my-IP” script at

Several years ago I built a little script to show my IP address, just as many other sites implement it. The difference to my script is that it doesn’t display any kind of commercial or other annoying stuff. Just the IP address and a few other information. The script is accessible under

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