OpenStack Neutron Packet Walkthrough (DVR)

OpenStack Neutron Packet Walkthrough (DVR).
Twitter: @davidmahler
LinkedIn:   / davidmahler  

Links:
Me:   / davidmahler  
OpenStack Documentation: http://docs.openstack.org
RDO: http://rdoproject.org
Assaf Muller's Blog: http://assafmuller.com
Introduction to Neutron:    • Introduction to OpenStack Neutron  
Linux Network Namespaces:    • Introduction to Linux Network Namespaces  
Introduction to VXLAN:    • Introduction to Cloud Overlay Network...  
Introduction to Open vSwitch:    • Introduction to Open vSwitch (OVS)  
Introduction to OpenFlow:    • Introduction to OpenFlow  

Some commands used:
ip info
ip a

see routing table
ip route

see policy routing rules
ip rule list

see a particular routing table
ip route show table (table id)

list linux bridges
brctl show

packet capture, disable resolution, show mac/L2 info, filter on icmp
tcpdump -i (interface) -n -e icmp

list iptables rules
iptables -S

iptables rules for the nat table only
iptables -S -t nat

see open flow rules for a particular ovs instance and flow table
ovs-ofctl dump-flows (ovs instance name) table=(table number)

watch open flow rules counters move
watch -n.5 "ovs-ofctl dump-flows (ovs instance name) table=(table number) | grep -v n_packets=0"

see fowarding db of ovs
ovs-appctl fdb/show (ovs instance name)

see ovs instances and their ports
ovs-vsctl show

see open flow port numbers
ovs-ofctl show (ovs instance name)

list network namespaces
ip netns

go to a bash shell for a particular network namespace
ip netns exec (namespace id) bash

list neutron routers
neutron router-list

see where a neutron router is hosted
neutron l3-agent-list-hosting-router (router name)

status of proxy arp
cat /proc/sys/net/ipv4/conf/(interface name)/proxy_arp