OpenPGP vs S/MIME
S/MIME and OpenPGP similarity: both depends on public/private keys to encrypt/authenticate msg ( emails), difference: how to distribute the public keys. S/MIME is similar to TLS, need to depends on…
What is the difference between srtp and zrtp
SRTP sdp msg: v=0 o=jdoe 2890844526 2890842807 IN IP4 10.47.16.5 s=SDP Seminar i=A Seminar on the session description protocol u=http://www.example.com/seminars/sdp.pdf e=j.doe@example.com (Jane Doe) c=IN IP4 161.44.17.12/127 t=2873397496 2873404696 m=video 51372…
SSH protocol
How SSH2 works: (1) When a TCP connection is made by a client, the server responds with the protocol versions it supports. If the client can match one of the…
TLS/SSL handshake
The combination of Diffie-Hellman and the use of ephemeral session keys are what enables “Forward Secrecy”: even if an attacker gains access to the server’s private key they are…
some notes about BGP, OSPF/IS-IS, RIP/EIGRP
BGP: run on tcp 179, path vector protocol, 65K routes eBGP: append AS_PATH iBGP: ( the same AS number), iBGP need full mesh, thus could use Route Reflector (RR, need to…
Apache Kafka big picture and quick start
What is Apache Kafka? ( big picture) I found the article http://www.confluent.io/blog/stream-data-platform-1/ ( from Jay Kreps) presented a very good big picture on what Kafka suppose to do: you can…
MPLS VPN/VRF
Why MPLS? Networks with more stringent QoS requirements might use IPSec-over-Internet for non-real-time traffic and MPLS for real-time and mission-critical traffic Basic MPLS, how it works: A good explanation is…
ipv6 testbed at home
It is quite easy to setup a ipv6 testbed at home now. (1) setup linux ipv6 router apt-get install radvd # on a vm or real box debian and copy the…
