03-30-2007 08:53 AM - edited 03-05-2019 03:12 PM
Hi,
I want to connect a router (7206VXR, NPE-G2, 12.4(11)T1) to 2 switches (6509, 12.2(18)SXF) at layer 2. The configuration I'm trying is:
router:
!
bridge irb
!
interface GigabitEthernet0/1
description - connection to switch2 gi5/2 -
no ip address
duplex auto
speed auto
media-type rj45
negotiation auto
bridge-group 1
!
interface GigabitEthernet0/2
description - connection to switch1 gi5/1 -
no ip address
duplex auto
speed auto
media-type sfp
negotiation auto
bridge-group 1
!
interface BVI1
ip address 10.37.123.4 255.255.255.0
!
bridge 1 protocol ieee
bridge 1 route ip
!
switch1:
!
vlan 123
!
interface GigabitEthernet5/1
description - connection to router gi0/2 -
switchport
switchport access vlan 123
switchport mode access
no ip address
!
interface vlan 123
ip address 10.37.123.1 255.255.255.0
!
switch2:
!
vlan 123
!
interface GigabitEthernet5/2
description - connection to router gi0/1 -
switchport
switchport access vlan 123
switchport mode access
no ip address
media-type rj45
!
interface vlan 123
ip address 10.37.123.2 255.255.255.0
!
This works well as long as the link choosen for forwarding from spanning tree first (here gi0/2) is online.
router#show spanning-tree brief
Bridge group 1
...
Interface Designated
Name Port ID Prio Cost Sts Cost Bridge ID Port ID
-------------------- ------- ---- ----- --- ----- -------------------- -------
GigabitEthernet0/1 128.2 128 4 BLK 0 32768 0019.a90a.f800 130.2
GigabitEthernet0/2 128.3 128 4 FWD 0 20480 0019.a90a.e800 130.1
If this link (the active one) goes down (by shutting down gi5/1 on switch1 for example) the traffic stops and the spanning tree changes to:
router#show spanning-tree brief
Bridge group 1
...
Interface Designated
Name Port ID Prio Cost Sts Cost Bridge ID Port ID
-------------------- ------- ---- ----- --- ----- -------------------- -------
GigabitEthernet0/1 128.2 128 4 FWD 0 32768 0019.a90a.f800 130.2
GigabitEthernet0/2 128.3 128 4 DWN 4 32768 0019.304d.881b 128.3
So far so good. But then the traffic don't resumes. And that is my problem, I expected the traffic to resume after the second link (gi0/1) is in forwarding state.
Am I doing something wrong?
Can someone of you give me a hint?
Or is there another way to connect one router to two switches and getting a redundant link at layer 2?
kind regards
Mark
03-31-2007 01:56 PM
Let's see the whole spanning-tree picture while G0/2 is down from the 2 switches and the router.
Type show spanning-tree vlan 123 and post results.
04-01-2007 11:41 PM
Hi
when interface gi0/2 on the router is shutdown the spanning-tree looks like:
router#sh spanning-tree brief
Bridge group 1
Spanning tree enabled protocol ieee
Root ID Priority 20480
Address 0019.a90a.e800
Cost 4
Port 2 (GigabitEthernet0/1)
Hello Time 2 sec Max Age 20 sec Forward Delay 6 sec
Bridge ID Priority 32768
Address 0019.304d.881b
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300
Interface Designated
Name Port ID Prio Cost Sts Cost Bridge ID Port ID
-------------------- ------- ---- ----- --- ----- -------------------- -------
GigabitEthernet0/1 128.2 128 4 FWD 0 32768 0019.a90a.f800 130.2
GigabitEthernet0/2 128.3 128 4 DWN 4 32768 0019.304d.881b 128.3
router#
switch1#sh spanning-tree vlan 123
MST15
Spanning tree enabled protocol mstp
Root ID Priority 24591
Address 0019.a90a.e800
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 6 sec
Bridge ID Priority 24591 (priority 24576 sys-id-ext 15)
Address 0019.a90a.e800
Hello Time 2 sec Max Age 20 sec Forward Delay 6 sec
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Te3/1 Desg FWD 2000 128.257 P2p
Gi8/1 Desg FWD 20000 128.897 P2p
Gi8/3 Back BLK 20000 128.899 P2p
switch2#sh spanning-tree vlan 123
MST15
Spanning tree enabled protocol mstp
Root ID Priority 24591
Address 0019.a90a.e800
Cost 2000
Port 257 (TenGigabitEthernet3/1)
Hello Time 2 sec Max Age 20 sec Forward Delay 6 sec
Bridge ID Priority 32783 (priority 32768 sys-id-ext 15)
Address 0019.a90a.f800
Hello Time 2 sec Max Age 20 sec Forward Delay 6 sec
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Te3/1 Root FWD 2000 128.257 P2p
Gi5/2 Desg FWD 20000 128.514 P2p Bound(STP)
Gi7/1 Altn BLK 10000 128.769 P2p
Gi7/3 Altn BLK 20000 128.771 P2p
04-03-2007 10:17 PM
any idea? anyone?
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