[j-nsp] EX routed VLAN counters and other issues

[Alexandre Snarskii]

On Thu, Mar 05, 2009 at 08:49:10PM -0800, will at loopfree.net wrote:
> I have been eval'ing an EX3200 for use as a small datacenter 
> distribution switch. The idea was to have a routed uplink to a bigger 
> router and routed VLANs to handoff to customers, using the EX as a 
> cheap router with a bunch of gig-e ports.
> 
> It appears that the switch doesn't consistently count traffic on the 
> RVI interfaces -- in a test enivronment with a routed VLAN uplink and a 
> separate routed VLAN to a customer, one of the RVIs counts transit 
> traffic while the other counts traffic to the local IP only (IP 
> actually on the switch interface).

The lack of statistics on RVI is my most hated misfeature of EX 
series too.. :( 

Well, there is a workaround - if you need to count bytes you can do 
it with the help of l3-subinterfaces, something like that: 

interface ge-0/0/1 { 
	vlan-tagging;
	uint 10 { 
		vlan-id 10;
		family inet { ..... }

One of disadvantages of this workaround is that in this config you 
are not able to switch vlans from that interface (all vlans must be 
terminated and routed locally), but there is workaround for that too: 
if you need to have both routed and switched vlans on interface - 
you may use hairpin connection, fortunately, vlan-ids is interface-
significant in vlan-tagging mode. 

> 
> FWIW it looks like Cisco 3550 counts local traffic only, but 3560 & 
> newer supposedly get it right and count transit traffic like a "real" 

No, that behaviour is not changed even in 35[67]0E..