Oh, i'm very sorry, my mistake, i mixed up interface names.
Big delay on lan interface, not wan.
If you interesting, here is the scheme in complete form:
http://scr.lexore.net/20150305-y1h-53kb.jpgWe have two virtualization servers with two VM on each: proxy and wanos.
Wanos servers placed between proxies for traffic compression.
When this schema run in production, after some time i see very big delay between wanos and proxy.
As i noted, this is on lan interface of wanos.
After reboot delay dissapear.
For example, in previous post i showed delay between wanos (10.250.254.2) and proxy (10.250.254.3).
After reboot delay is gone:
tc@wanos:~$ ping 10.250.254.3
PING 10.250.254.3 (10.250.254.3): 56 data bytes
64 bytes from 10.250.254.3: seq=1 ttl=64 time=0.857 ms
64 bytes from 10.250.254.3: seq=2 ttl=64 time=0.592 ms
64 bytes from 10.250.254.3: seq=3 ttl=64 time=0.644 ms
64 bytes from 10.250.254.3: seq=4 ttl=64 time=0.656 ms
64 bytes from 10.250.254.3: seq=5 ttl=64 time=0.635 ms
So, this delay appear after some time of work, when http traffic starts.
I saw this situation on both pairs of servers (proxy1-wanos1 and proxy2-wanos2) - big delay on lan interface after some time of work.
I don't think, that this is loop (if you about traffic) because after reboot all is fine.
About your question to simulate i'll try to explain.
But first i want to say, that i'm ready to provide access to wanos servers if you interested or if will be problems with reproduce steps.
On virtualization server i use package "libvirt-bin" for manage VMs.
I used GUI virt-manager to create and configure VMs.
But you can use cli command virsh and xml files (see below).
I created VM with 2 nics (driver pcnet) for wanos.
For wanos hdd i convert vmdk image to raw format.
I attached xml with this VM config (wanos-msk1.xml).
You can create VM with command:
virsh create wanos-msk1.xml
Vm for wanos has this settings:
mem: 2GB
cpu: 4
hdd: /var/lib/libvirt/images/wanos-msk1.raw
hdd format: raw
hdd size: 64 GB
lan interface connects to bridge: br1
wan interface connects to bridge: host2wanos
VNC session for this VM available on port 5900.
And i created VM with 2 nics for proxy, and install ubuntu to it.
I also attached xml for it (proxy-msk1.xml)
You can create VM with command:
virsh create proxy-msk1.xml
This VM has this settings:
mem: 2GB
cpu: 4
hdd: /var/lib/libvirt/images/proxy-msk1.raw
hdd format: raw
hdd size: 10GB
interface to wanos connects to bridge: br1
interface to inet connects to bridge: br0
VNC session for this VM available on port 5901.
Before start VMs, you need to create three bridges:
* To connect proxy with real network (in my configs it has name br0)
If you virtualization server has nic eth0, commands will be:
brctl addbr br0
brctl addif br0 eth0
ip a del <ip/mask> dev eth0
ip a add <ip/mask> dev br0
ip ro add default via <dgw> #default gateway can gone after delete ip
* to connect proxy and wanos (in my configs it has name br1)
brctl addbr br1
* to connect wanos with real word
in my configs libvirt creates additional inteface on virtualization server.
You can create it with command:
virsh net-create <host2wanos.xml>
When network ready, you can start VM's with commands:
virsh start proxy-msk1
virsh start wanos-msk1
libvirt will create virtual nics (vnet*) and connect they to bridges.