People,
Good afternoon,
We have a curious situation in a client's environment.
It has a M7i router with 2 IQ2E (4 GE) PICs.
It wants one of its PICs plugged into a L2 switch (802.1Q Trunk Mode)
and the another one plugged (via 1 giga of 4 ports only) to another L2
switch.
M7i
/ \
S1 S2
Both Giga ports are simpled configured like:
nterfaces {
ge-0/0/0 {
vlan-tagging;
nterfaces {
ge-0/1/0 {
vlan-tagging;
L2 Trunk Ethernet only without L3 configuration.
It is possible to get flow information about the encapsulated vlans
(10,20,30,40, etc) inside the trunk traffic ? ... without configuring ip
(4 or 6) or creating vlan interfaces ?
It is possible to get cflow working in a L2 way ?
Does anyone has configured it before using JUNIPER ? Can you send or
point to me some samples of configuration ?
Thanks a lot,
Giuliano
It is possible to get cflow working in a L2 way ?
Hi Giuliano,
The short answer is, unfortunately, no.
NetFlow v5 does not have any fields for Layer 2 information: http://netflow.caligare.com/netflow_v5.htm
Although NetFlow v9 does have such fields, you (a) only get NetFlow v9 functionality on a Juniper if you have a Services PIC installed and (b) are limited by the NetFlow v9 templates that JUNOS implements. See the section titled "Fields Included in Each Template Type" for a description of each NetFlow v9 template at Configuring Flow Aggregation to Use Version 9 Flow Templates - JUNOS 9.5 Services Interfaces Configuration Guide.
Juniper supports sFlow (which would give you L2 info) on their EX switches, but not on their routers. Perhaps when/if IPFIX support comes along, you might be able to get what you are looking for.
You could use port mirroring or an optical tap with various open-source tools running on a Unix host to do the kind of monitoring you are looking for.
Cheers,
-Chris
Besides the Juniper specifics on which i do agree.
The fact that NetFlow v5 doesn't carry L2 information doesn't
per-se imply it can't be theorically applied to L2 interfaces
and report on upper layers - making it fair, on a multi-layer
thing. Which is the underlying issue here.
Cheers,
Paolo