I am using the Ryu Controller to send the packets from source to destination. I want to check the delay and bandwidth of the links created. How can I access these parameters?
You can:
Either configure this in the topology when you are setting it up
Use Ping/Iperf to figure out what the delay/bw is respectively
Check the configured interface's parameters using TC to get access to this.
Related
i have a measurement setup where i want to trigger an oscilloscope base on a network package arriving. I have good results for a few seconds but somewhere between 20s and 40s i get a wrong trigger. My research showed that this could come from the arp packages send from the device. I tried to disable the arp sending but then the whole network went down. Now i'm trying to find a solution where i change the rate at which the arp packets are send without success. So i'm asking you if you know a way to either disable or send as few arp request as possible.
For your information i'm working on a Linux machine. Any help would be appreciated.
I allready tried:
#ip link set arp off dev eth0 <--- results in network down
changing the values for:
/proc/sys/net/ipv4/neigh/default/gc_interval
/proc/sys/net/ipv4/neigh/default/gc_stale_time
/proc/sys/net/ipv4/route/gc_interval
/proc/sys/net/ipv4/route/gc_timeout
with no success
Thx draufunddran
TL;DR: Disabling ARP on your machine will eventually cause other nodes on the network to stop sending packets to your machine (that is why your network appears to go down).
If you want to completely disable ARP packets on your network, you will need to manually program ARP tables on other nodes on your LAN (subnet) so that they know how to map your host's IP to a MAC address to send to on the LAN. This is a difficult thing to do if even possible since some nodes on your network may not offer the ability to program their ARP tables manually.
I have an application on my linux host that communicates via UDP to another machine via 10G ethernet. The machine on the other end does not respond to ARP requests. I am able to get it's MAC address through other means (a different interface, on
Is there a way to programmatically get this information into the arp table w/out privileged status?
I know I can on a command line issue "sudo arp -s 1.2.3.4 AA:BB:CC:DD:EE:FF" every time I power it up.
I know I can add "1.2.3.4 AA:BB:CC:DD:EE:FF" to etc/ethers
I know that as a priviledged usr/process I can issue an ioctl to SIOCSARP.
All of these mechanism's require sudo/root access. I read something about giving the application "CAP_NET_ADMIN" permissions.
I'm looking for this capability so that the end users don't need to do any of the above. It seems like, If I, w/out sudo/root, can open a socket that determines the need for this network information, there should be a way for me, w/out sudo/root, to provide it.
No, you can't edit ARP information as non-root. This makes sense, as otherwise malicious attacker would be able to modify ARP tables and completely disrupt network communication and compromise security.
The solution to your problem is to fix your network configuration.
Currently, I'm writing an application on top of Ryu, the Open-source OpenFlow Controller.
To create an OF-Config connection (or OVSDB connection), I think I have to get the IP address of each switch connected to the Ryu controller. However, I cannot find the API that converts the Datapath object or datapath id to the IP address of the switch.
So, if there is such an API, I want to know about it. If not, I'm looking forward to receiving some comments about the way to make the connections without the IP addresses.
#set_ev_cls(event.EventSwitchEnter)
def switch_features_handler(self, ev):
address = ev.switch.dp.address
dpid = ev.switch.dp.id
"address" is a tuple of (ip_address, port) and "dpid" is the datapath id.
Byungjoon are you using mininet?
If you are, all the switches are instantiated with the localhost ip address (This is mininet's default behavior). The controller distinguishes between switches using the tcp port.
As far as I know, you only need to know the dpid of the switch in order to send OF messages. This is what the sample l2-learning switch is doing: https://github.com/osrg/ryu/blob/master/ryu/app/simple_switch_13.py
I am also try to communicate with the switches using Ryu controller. I am using the above sample as my basic code and adding on top of it. It is not done yet (so you might see some bugs) but it's good starting point. Here is the link: https://github.com/Ehsan70/RyuApps/blob/master/l2.py
for latest version of ryu, you should use following code.
#set_ev_cls(ofp_event.EventOFPSwitchFeatures, CONFIG_DISPATCHER)
def _switch_features_handler(self, ev):
print(ev.msg.datapath.address)
I have written a module that will configure network settings on my system but I can't apply the manifest because before a manifest is applied it does "facter ipaddress" to find and present global facts.
Does it mean that in order to apply puppet manifest we must have IP configured ?
So I have a system that has no IP address configured and i want to use puppet to configure that IP address for me, for that I am asking user to input IP address which i save in a .csv file, then I am using a template to configure if-eth0 file. Template will do extlookup to fill up the fields in template and template is finally called upon inside a manifest. So the problem is that before anything is applied by puppet, it fails to run with following error
facter ip address unable to resolve IP , reason anonymous
I am not sure about the actual question (if IP is indeed needed). However, if I understand correctly you can try one of the two workarounds:
Enable DHCP
This way when your system boots will take a little bit more time (assuming there is no DHCP service on the network). A timeout will occur which, in most of the cases, results in a default IP (169.254.Y.Z if I remember). In this case you may need to stop/kill the dhcp client process before applying static IP or restart the interface to get the new configuration.
Assign default static IP
If you know that puppet configuration will be applied no matter what (maybe a call in rc.local?), you can configure your interface with a static IP (ie 10.1.1.10) to avoid the error message. This is temporary since once puppet runs, the correct configuration will be applied.
Hope it helps,
Andreas
I'm new to Esper and am interested in using it to send event data via a network so consequently interested in the EsperIOSocketAdapter
It appears that SocketAdapter can only bind to a specific port which is fine if there is only one network adapter but is it possible to configure the SocketAdapter to bind to a specific network adapter too by specifying its IP address?
Please create a Esper JIRA if you need this feature.
You could also use the Esper API directly and use your own Java socket transport.