31 Jan

DHCP domain-search on Juniper SRX

DHCP Option 119

In the last few years, the DHCP service in enterprises got more and more integrated into complex management and provisioning systems or became a part of the Active Directory solutions. Routers, switches, wireless controllers or other devices in such networks act as DHCP Proxy instead of DHCP Servers just sending the requests to the central server. But the feature itself is not dead! Sometimes you need to run it locally and not only provide the IP address and default gateway to the client device but also DNS servers information or domain-search parameters. The last feature is an DHCP Option 119 and I put it in “tricky, non-obvious DHCP config”, together with bunch of other DHCP options.

The central point of my home and lab networks is the Juniper SRX220H – it is quite old but the services and its performance fulfills my requirements so far. One of the services it provides is DHCP Server for some of the VLANs. I was not really missing the domain-search feature so far but decided to add it to make my work more convenient. This feature configuration is not straightforward, and there are many misleading guides about setting up this feature on different platforms or operating systems. Let me show you how it works on Juniper.

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01 Jun

How to manage simulation in VIRL from local network

Cisco and VIRL logos

I’ve been using Cisco VIRL for over two years for both learning technologies and testing new solutions as PoC. Accessing devices in simulation via embedded console link is easy but not efficient. I always wanted to manage simulation in VIRL from my laptop not desktop PC. Also in many scenarios you  may want to connect external servers like netflow collector or IPAM software you wanna test. Also it’s quite handy to have access to running simulation form Internet, isn’t it?

Let me show you how I connect Cisco VIRL running simulation to other devices in my network and to Internet. In this tutorial I assume that you didn’t change default VIRL networking configuration.

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19 Apr

BFD – presentation from PLNOG10

BFD – presentation from PLNOG10

A little late but here it is – presentation from my session on PLNOG10 conference that took place in Warsaw 28th Feb – 1st Match. This is one of best conferences for Service Providers in country and region.

This time I was talking about BFD protocol, deployment strategies and caveats. The presentation was in Polish but slides are in English.