Sflow activated, agent configured but no data arrive on host

[xDanielX]

i have an OmniSwitch 6900-X20 with Release 8.4.1.170.R01 (yes i know its pretty old but we try to avoid downtimes..)
i have virtual chassis mode enabled with EMP-VC Interface IP 192.168.0.1 , 255.255.255.0, i can reach the web interface. the emp port is connected untagged into an port of another switch VLAN 99 for management of switches. i have another host where sflow server runs and listens for connections on port 6343 udp with ip 192.168.0.3, 255.255.255.0, so far so good.
i did the command
ip service source-IP EMP-VC 192.168.0.1 sflow

that worked, now the sflow agent is shown as the ip 192.168.0.1. alright
i activated an receiver with following command:

sflow receiver 1 name Receiver address 192.168.0.3
then i activated samplers for the receiver 1 with rate 1 and sample header size 128 (standard) for all ports and activated pollers for all interfaces with receiver 1 and interval 30s.
when i enter
debug sflow dump statistics
it tells me that it sends datagrams for slot 1/1 to receiver 1 for example, i see it is counting upwards.
but at the server 192.168.0.3, there are never arriving any packets on port 6343, i even checked with different software and simple udp tester if there is any traffic coming in, but there is no packet arriving at this port.
the thing i see on the debug sflow dump statistics command is that the emp slot is sending no datagrams, which could be the reason.
so what i want to achieve is that the data of sflow are sent via EMP port to the 192.168.0.3 sflow host, but the data never seem to arrive tho..

[silvio]

I never tested sflow via EMP.
I have found an old KB article at ALE for 8.3.1.160.R02 with the same configuration and problem.
The answer was:
EMP ports cannot be used for Sflow service, as it should be used for management purpose only. Hence, it is recommended to use any front panel interface for Sflow service.

If possible you should test the same with a newer SW-release (f.e. at a 6860E with EMP) ... maybe it works now.
best regards
Silvio

[Gleylancer]

I was thinking it would be something like this when I read the initial post. Thanks for confirming, Silvio.

[xDanielX]

thank you for looking it up! i checked a few times and this post is just edited, since at first i was stuck at this "no emp" thingy.. but now i solved it.

maan this was annoying. you see, if you try to add an ip interface on the GUI via webinterface you always get the message you cannot add an interface not bound to an physical port. but if you simply connect via SSH you simply add the interface with the ip interface command, you specify the needed vlan and voilá, it works! now i simply had to use an different ip range from the one i defined on EMP interface and use another ip range like 192.168.1.1, 192.168.1.2, add another ip to the server ethernet card and such but that was really no big deal now. then i configured again the receiver settings to the new set ip on the server, and i see the flow is streaming. took me way too long to figure out and i think its really really sad. some questions arise from this:

*why is it not documented that EMP is not supporting sflow in the documentation of this switch? why did i need to go to these lengths to find it in an unofficial board?
* why the heck can i add the interface for an vlan via ssh but not via webinterface? was it such a big deal to make it possible to add a vlan interface only? i dont't understand alcatel-lucent at this point.

[silvio]

I have checked at the web. You create an ip interface with a new name. And than you modify it with an ip addresss+mask and bound it to a vlan. Same like in the cli.