Tuesday, January 6, 2015

Making sense of SDN

I came across this three part video in youtube, which was recorded back in August 2012, i see it is interesting and useful.






OpenSSL User Interface

An excellent tool for OpenSSL (working version) tool i came across http://sourceforge.net/projects/opensslui/

  • It has a installable windows UI
  • It uses OpenSSL equivalent command to create and manage CA certs, Keys for PKI



References

Network Policy Management

Way too many times we had come across about the complexities with setting up policies / rules in network equipments following their proprietary approaches.

In the end , there is no one-stop-shop ( a CLI or single pane ) to set up this classic multi-vendor problem.

As a simple rule of thumb, a network service policy , when written as words looks like this
"Input trunk + forwarding policy = output truck"

A centralized control traffic management standards is the Open Flow Protocol and managing policies to be applied with distinct network equipment.

An orchestrator project like openstack , drives this thru initiatives like https://wiki.openstack.org/wiki/Congress

Policy Language

The policy language for Congress is Datalog, which is basically SQL but with a syntax that is closer to traditional programming languages. This declarative language was chosen because its semantics are well-known to a broad range of DevOps, yet its syntax is more terse making it better suited for expressing real-world policies. The grammar is given below.
<policy> ::= <rule>*
<rule> ::= <atom> COLONMINUS <literal> (COMMA <literal>)*
<literal> ::= <atom>
<literal> ::= NOT <atom>
<atom> ::= TABLENAME LPAREN <term> (COMMA <term>)* RPAREN
<term> ::= INTEGER | FLOAT | STRING | VARIABLE  

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