[j-nsp] Q-in-Q configuration on Juniper Gig interface

sthaug at nethelp.no sthaug at nethelp.no
Fri May 30 11:09:59 EDT 2008

> > > I don't think you need IQ, IIRC anything modern (SFP-based GE's, 10GE, MX
> > > ports, etc) can do this.
> > 
> > That is true for the MX ports, but not on "regular" M series PICs as
> > far as I know.
> > 
> > Have you gotten it to work?
> The docs I have say flexible-ethernet-services was supported on 1GE SFP 
> PICs in 6.3, but there is no support for fixed-optics GE PICs.

This is true. But note that flexible-ethernet-services is not the same as
stacked-vlan-tagging or flexible-vlan-tagging.

> I haven't 
> actually tried it myself (the only GE-SFP PICs I used for double-tagging 
> just happened to be IQ), but I'm 99% confident that this works unless a 
> lot of people have been lying to me. :)

Afraid you'll be disappointed then. This is from an M7i:

FPC 0                                                    E-FPC
  PIC 1          REV 08   750-010238   PB7782            1x G/E SFP, 1000 BASE
    Xcvr 0                NON-JNPR     PR05014273        SFP-T

ge-0/1/0 {
    encapsulation flexible-ethernet-services;
    unit 1 {
        vlan-tags outer 2 inner 3;
        family inet {

JunOS lets you configure it - but it doesn't work, and there are a couple
of nasty error message logged:

May 30 14:58:34  xyzzy /kernel: ether_iflconfig:ge-0/1/0 (porttype 57) does not support vlan-tags outer <vlan-id> inner <vlan-id> option
May 30 14:58:34  xyzzy dcd[4326]: DCD_CONFIG_WRITE_FAILED: Interface ge-0/1/0, configuration write failed for an IFL ADD: Operation not supported

I'd argue that you shouldn't be allowed to configure this at all, since
it doesn't work.

Steinar Haug, Nethelp consulting, sthaug at nethelp.no

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