[c-nsp] spanning-tree for local switching on ASR920

[Gert Doering]

Hi,

apologies if I've overlooked the obvious, but my google fu is failing me,
and my "read cli help and guess" fu is not better today.

I have an ASR920 that is supposed to have gi0/0/10 and gi0/0/11 in
the same bridge group, with a routed IP:

interface GigabitEthernet0/0/10
 no ip address
 media-type auto-select
 negotiation auto
 cdp enable
 service instance 10 ethernet
  encapsulation untagged
  l2protocol peer stp
  bridge-domain 10
 !
interface GigabitEthernet0/0/11
 no ip address
 media-type auto-select
 negotiation auto
 cdp enable
 service instance 10 ethernet
  encapsulation untagged
  l2protocol peer stp
  bridge-domain 10
 !
interface BDI10
 ip address .... 
end


(the goal is "customer wants to connect redundant firewalls to this box,
and they need to see each other on L2, and see their routed interface
on the ASR920").

The basic part works, but now the interesting bit: spanning-tree.

Connecting gi0/0/10 and gi0/0/11 shows how performant the hardware
is...

  5 minute input rate 945978000 bits/sec, 337840 packets/sec
  5 minute output rate 945974000 bits/sec, 337840 packets/sec

... and how robust the control plane (no impact) - this is great news :-)
- but I had *hoped* that spanning-tree would actually disable one of
the ports, at least that's how I read the docs on CCO on "STP on ASR920".

I have tried all variants with PVSTP and MST that I could think of, 
but none lead to more than this:

ASR920#show spanning-tree su
Switch is in pvst mode
Root bridge for: none
EtherChannel misconfig guard is enabled
Extended system ID           is enabled
Portfast Default             is disabled
PortFast BPDU Guard Default  is disabled
Portfast BPDU Filter Default is disabled
Loopguard Default            is disabled
UplinkFast                   is disabled
BackboneFast                 is disabled
Pathcost method used         is short

Name                   Blocking Listening Learning Forwarding STP Active
---------------------- -------- --------- -------- ---------- ----------
Total                        0         0        0          0          0
ASR920#show spanning-tree int g0/0/10
no spanning tree info available for GigabitEthernet0/0/10

ASR920#show spanning-tree int g0/0/11
no spanning tree info available for GigabitEthernet0/0/11

... as in "there is no spanning tree running here", and I can't find a 
way to make it.

Before I open a TAC case here - has one of you a working example of
this, that is

  - ASR920
  - two or more local ports (untagged or default) in the same bridge-group
    ("forming a switch")
  - spanning-tree enabled and working

we do not want tagged (customer gear).  We could go with split-horizon,
but we also want to understand the capabilities of this box, and why it
is not behaving.

IOS is asr920-universalk9_npe.03.18.03.S.156-2.S3-std.bin

thanks,

gert

-- 
USENET is *not* the non-clickable part of WWW!
                                                           //www.muc.de/~gert/
Gert Doering - Munich, Germany                             gert at greenie.muc.de
fax: +49-89-35655025                        gert at net.informatik.tu-muenchen.de
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