NI PXI 8176 broadcasting Version 2 Spanning Tree Updates
I am not the owner of this device, but I am in IT. We had an NI PXI8176 suddenly start broadcasting version 2 spanning tree protocols over the network... this is a mystery to us. Has anyone ever seen this, or have theories why it would do this?
thanks
Nan
I'm not very familiar with spanning tree protocols, but I thought that they were for network bridges and switches.
Have you had any viruses on that PXI-8176? Think of the PXI-8176 as a laptop in a different form factor when troubleshooting this kind of stuff. This sounds like an OS/virus/network issue.
Good luck.
Jack
Similar Messages
-
ISE - 802.1X - Loop not detected by spanning-tree
Hello,
I have recently implemented the 802.1X on switchs 3750-X running 15.0(2)SE IOS version.
The spanning-tree bpdufilter and bpduguard are globally enabled on the switchs.
A user has created a loop on the network by connecting its Cisco IP-Phone twice on the network : one wire connected normally from switch to the RJ-45 phone connector and the second wire that should be connected to the PC had also been connected to the switch !
The loop created has not been detected by the switch !
I have made several tests and re-created the problem 3 times on 4 (only one time, the loop has been detected by bpduguard 20 seconds after the port up).
Notice that without 802.1X configured on the same switch port, the loop is quickly detected and ports are err-disabled shutdown.
Switch port with 802.1X is following :
interface GigabitEthernet1/0/9
switchport access vlan 950
switchport mode access
switchport nonegotiate
switchport voice vlan 955
no logging event link-status
authentication control-direction in
authentication event fail action next-method
authentication event server dead action reinitialize vlan 950
authentication event server dead action authorize voice
authentication event server alive action reinitialize
authentication host-mode multi-auth
authentication order dot1x mab
authentication priority dot1x mab
authentication port-control auto
authentication periodic
authentication timer reauthenticate server
mab
dot1x pae authenticator
dot1x timeout tx-period 10
storm-control broadcast level 10.00
storm-control multicast level 10.00
spanning-tree portfast
If I change the host-mode to multi-domain, a MAC violation restriction occurs and shutdown the port. But this is not the config I need.
Is there any reason for spanning-tree not works properly with 802.1X ?
Thanks,
OlivierHello Olivier
When using bpdufilter, bpduguard and portfast all at the same time there are many things going on which are not well documented. Now when you add 802.1x to the mix then you really have no documentation. I had to do many labs on my own to finally have my configuration, and also discovered some bugs. According to my experience you shouldn't use bpdufilter and you should use bpduguard on the switchport not in the global config.
Please read the following links about the differences between global and port bpdufilter, differences between global and port bpduguard, configuring bpduguard along with portfast , configuring bpdufilter along with portfast, and configuring bpduguard along with bpdufilter.
http://aitaseller.wordpress.com/2010/01/17/bpdu-filter-vs-bpdu-guard-what-is-the-difference/
http://costiser.wordpress.com/2011/05/23/subtle-difference-for-portfast-bpdufilter-used-together-globally-or-at-interface-level/
https://learningnetwork.cisco.com/thread/21103
http://blog.ipexpert.com/2010/12/06/bpdu-filter-and-bpdu-guard/
Please rate if this helps -
Is anyone aware of a bug in version 15.0(2)EX5 for 2960X Switches that would cause a switch in the master role to stop linking in new ports in green (and passing traffic). I have 2 2960X-48FPD-L Switches in a stack and whichever switch I designate master will only link new connections in orange and not pass traffic. All ports linked in show up/up and can be seen in a show cdp neighbor but won't pass any other traffic.
If I unplug the Stacking cables both switches become masters and ports linked in green on the previous member switch stay green, but after it switches to master any new connections plugged in only link in orange.
If I switch priorities and reboot the problem switches to the new master switch and the problem goes away on the member switch.
Also, a switch in the master role does not show any spanning tree instances for ports in the orange link state.
Has anyone seen this issue and do you know of a solution?
JimA quick update for those with this same problem.
1. 15.2(3)E turned out to be very unstable causing my switch stack to randomly lockup/reboot one of the switches about once a week.
2. I downgraded back to 15.0(2)EX5 but found a workaround. It turns out the switch stack with the 15.0 versions does not like the switchport voice vlan command on any of the interfaces on the master switch. I simply removed the voice vlan configuration on the interfaces and all the switch ports linked in just fine. I would prefer to run the phones on a voice vlan, but it still works without, just the PC's and phones are on the same vlan.
Jim -
Spanning-tree not working: SG500 to Cat3650
Hi All,
Trying to turn up a new site. I have 2 switches: Cat 3650 & SG500-52P. I want to connect up two ethernet cables between these switches in the event one fails, STP will put the blocked one in forwarding. However, when I connect up the 2nd ethernet cable, I get the following:
IPADTBL-N-IPDUPLICATE: Duplicate IP address 192.168.5.232 from MAC a0:ec:f9:ef:6a:18 was detected on VLAN 1, port gi1/1/24
This log message is then followed by the network locking up & crashing until I remove the 2nd cable (i.e. STP Loop). Removing the redundant cable solves the problem. This is because STP is allowing both links to transitioning to forwarding state (confirmed in show spanning-tree & show cdp neighbor).
Why is spanning-tree not correctly blocking one of the lines? Is that type of architecture not supported when there is an SG300/500 in the equation?
Configs below:
Core 3650: (box configs basically)
Switch#show run
Building configuration...
Current configuration : 2686 bytes
! Last configuration change at 10:01:53 UTC Thu Jan 22 2015
! NVRAM config last updated at 09:24:03 UTC Thu Jan 22 2015
version 15.0
no service pad
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
service compress-config
hostname Switch
boot-start-marker
boot-end-marker
vrf definition Mgmt-vrf
address-family ipv4
exit-address-family
address-family ipv6
exit-address-family
logging console emergencies
enable secret 5 $1$Qi5N$u/5q1HESY/TyQsPFNKVah1
no aaa new-model
clock timezone UTC -6 0
clock summer-time UTC recurring
switch 1 provision ws-c3650-24ts
ip device tracking
diagnostic bootup level minimal
spanning-tree mode pvst
spanning-tree extend system-id
spanning-tree vlan 1 priority 24576
redundancy
mode sso
class-map match-any non-client-nrt-class
match non-client-nrt
policy-map port_child_policy
class non-client-nrt-class
bandwidth remaining ratio 10
interface GigabitEthernet0/0
vrf forwarding Mgmt-vrf
no ip address
negotiation auto
interface GigabitEthernet1/0/1
interface GigabitEthernet1/0/2
interface GigabitEthernet1/0/3
interface GigabitEthernet1/0/4
interface GigabitEthernet1/0/5
interface GigabitEthernet1/0/6
interface GigabitEthernet1/0/7
interface GigabitEthernet1/0/8
interface GigabitEthernet1/0/9
interface GigabitEthernet1/0/10
interface GigabitEthernet1/0/11
interface GigabitEthernet1/0/12
interface GigabitEthernet1/0/13
interface GigabitEthernet1/0/14
interface GigabitEthernet1/0/15
interface GigabitEthernet1/0/16
interface GigabitEthernet1/0/17
interface GigabitEthernet1/0/18
interface GigabitEthernet1/0/19
interface GigabitEthernet1/0/20
interface GigabitEthernet1/0/21
interface GigabitEthernet1/0/22
interface GigabitEthernet1/0/23
interface GigabitEthernet1/0/24
interface GigabitEthernet1/1/1
interface GigabitEthernet1/1/2
interface GigabitEthernet1/1/3
interface GigabitEthernet1/1/4
interface Vlan1
ip address 192.168.5.230 255.255.255.0
ip default-gateway 192.168.5.1
ip http server
ip http secure-server
line con 0
exec-timeout 0 0
stopbits 1
line aux 0
line vty 0 4
password scrubbed
login
line vty 5 15
password scrubbed
login
wsma agent exec
profile httplistener
profile httpslistener
wsma agent config
profile httplistener
profile httpslistener
wsma agent filesys
profile httplistener
profile httpslistener
wsma agent notify
profile httplistener
profile httpslistener
wsma profile listener httplistener
transport http
wsma profile listener httpslistener
transport https
ap group default-group
end
SG500 Switch:
switchff1182#show run
config-file-header
switchff1182
v1.3.0.62 / R750_NIK_1_3_647_260
CLI v1.0
set system mode switch queues-mode 4
file SSD indicator encrypted
ssd-control-start
ssd config
ssd file passphrase control unrestricted
no ssd file integrity control
ssd-control-end cb0a3fdb1f3a1af4e4430033719968c0
voice vlan oui-table add 0001e3 Siemens_AG_phone________
voice vlan oui-table add 00036b Cisco_phone_____________
voice vlan oui-table add 00096e Avaya___________________
voice vlan oui-table add 000fe2 H3C_Aolynk______________
voice vlan oui-table add 0060b9 Philips_and_NEC_AG_phone
voice vlan oui-table add 00d01e Pingtel_phone___________
voice vlan oui-table add 00e075 Polycom/Veritel_phone___
voice vlan oui-table add 00e0bb 3Com_phone______________
hostname switchff1182
no passwords complexity enable
username cisco password encrypted scrubbed privilege 15
ip ssh server
snmp-server server
no ip http server
ip telnet server
interface vlan 1
ip address 192.168.5.231 255.255.255.0
no ip address dhcp
exit
ip default-gateway 192.168.5.1Hi Peter,
Thanks for replying. Unfortunately (or fortunately if it worked), STP is running and BPDU's are flooding below:
SW500A#show spanning-tree
Spanning tree enabled mode RSTP
Default port cost method: long
Root ID Priority 24577
Address a0:ec:f9:ef:6a:00
Cost 20000
Port gi1/1/43
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32768
Address 2c:3e:cf:ff:11:82
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
SW500A#show spanning-tree bpdu
Global: Flooding
I guess I'm doing etherchannels instead of redundant links :-/
This is one of many reasons why I regret these small business models being made; A lot of things that are polished and functional in the enterprise grade (i.e. real switches) just don't seem to work on these units. But unfortunately, as the price is significantly cheaper, companies will continue purchasing these over the better quality units, and engineers like myself will be stuck working with the cut-corners version of a Cisco switch. -
Prime Infrastructure 2.2 - Network Topology View - Spanning Tree View
Hello Team,
Is it possible on PI 2.2 (latest version) under Maps/Network Topology View to be able to "monitor" the spanning-tree performance?
thanks in advance,
GeorgeSorry but that's not a currently offered feature.
It would be nice - the Netsys product that Cisco acquired 18-1/2 years ago (and subsequently abandoned) used to do this quite nicely. -
Here is the problem we are having , we have a 2950 hooked to a 6509 hybrid dist box with approx 90 vlans on it . We hook up a new 2950 and we get the following message, Dec 21 19:47:45.116: %SPANTREE_VLAN_SW-2-MAX_INSTANCE: Platform limit of 64 STP instances exceeded. No instance created. Ok , I know about the spanning tree issues with the 2950 only having limited PVST instances . But up at the dist side we have "manually pruned off all but 5 vlans on the trunk feeding this 2950 with the "clear trunk" command . I thought manually pruning off the vlans from the trunk would eliminate this problem , maybe i have a misunderstanding of how this works. Also the message on the 2950 complains about it only having 64 instances of spanning tree yet when you do a "show vtp status it says it supports 250 instances locally so whats up with that , 2950 running 12.1.22EA4 . So I guess I'm asking is there any way around this for the 2950 . Also in client/server mode do you have to manually prune off the vlans on both the server side and the client side ??
Hello Glen,
I guess instead of manually pruning the VLANs off the trunk, you could also try and enable VTP pruning globally on the 6509 (set vtp pruning enable). I assume you have the 6509 configured as the VTP server (set vtp mode server) ?
I am not sure if CatOS and IOS defaults to the same VTP version, can you check this (with 'show vtp domain' for CatOS and 'show vtp status' for the IOS switch) ?
Also, in a purely IOS environment, manually pruning VLANs off a trunk requires doing that only on the server side, but with a mix of CatOS and IOS, it might have to be done on both sides, you might want to give it a try and use the 'switchport trunk allowed' command on the 2950 as well...
Regards,
GP -
I am having an issue where 2 2960X-48FPD-L Switches in a redundant flexstack (stack port 1 SW1 to port 2 SW2 and port 2 SW1 to port 1 SW2) ring.
At first running the 15.0(2).EX5 (and earlier EX3, and EX4) version IOS yielded all the ports on the stack master switch refusing to run spanning tree and would only link in amber and not pass any traffic other than CDP information (the slave switch linked in fine).
I upgraded to 15.2(3)E and this solved the problem of the ports not linking in green and participating in spanning tree.
Now, however, about every week or two I lose connectivity to the switch stack and I was able to go to the switch stack locally and found that for some reason the switch stack is blocking and unblocking VLANs on StackPort1 frequently (see below). When I was at the site, I sometimes had connectivity, sometimes not. A stack hard reboot brought everything back up, but this is the second time this has occurred and I would expect the same problem in the next week or so.
Has anyone else run into these issues, and have you found a solution?
I'm guessing that if I either get rid of the redundancy on the switch stack or stack using Ethernet cables between switches the problem will go away, but then what is the point of using stackable switches in a non redundant low speed stack. It seems to me that Spanning tree thinks that I have a spanning tree loop going on with the stack ports which I didn't even think was possible.
What do you think?
Jim
_BAD_TLV: Received SSTP BPDU with bad TLV on StackPort1 VLAN1.
Mar 11 09:02:59: %SPANTREE-2-UNBLOCK_CONSIST_PORT: Unblocking StackPort1 on VLAN0307. Port consistency restored.
Mar 11 09:03:16: %SPANTREE-2-RECV_BAD_TLV: Received SSTP BPDU with bad TLV on StackPort1 VLAN1.
Mar 11 09:03:27: %SPANTREE-2-BLOCK_PVID_PEER: Blocking StackPort1 on VLAN0307. Inconsistent peer vlan.
Mar 11 09:03:42: %SPANTREE-2-UNBLOCK_CONSIST_PORT: Unblocking StackPort1 on VLAN0307. Port consistency restored.
Mar 11 09:03:46: %SPANTREE-2-RECV_BAD_TLV: Received SSTP BPDU with bad TLV on StackPort1 VLAN1.
Mar 11 09:03:47: %SPANTREE-2-BLOCK_PVID_PEER: Blocking StackPort1 on VLAN0307. Inconsistent peer vlan.
Mar 11 09:04:12: %SPANTREE-2-UNBLOCK_CONSIST_PORT: Unblocking StackPort1 on VLAN0307. Port consistency restored.
Mar 11 09:04:22: %SPANTREE-2-RECV_BAD_TLV: Received SSTP BPDU with bad TLV on StackPort1 VLAN1.
Mar 11 09:04:56: %SPANTREE-2-RECV_BAD_TLV: Received SSTP BPDU with bad TLV on StackPort1 VLAN1.
Mar 11 09:05:13: %SPANTREE-2-RECV_PVID_ERR: Received BPDU with inconsistent peer vlan id 207 on StackPort1 VLAN307.
Mar 11 09:05:13: %SPANTREE-2-BLOCK_PVID_LOCAL: Blocking StackPort1 on VLAN0307. Inconsistent local vlan.
Mar 11 09:05:30: %SPANTREE-2-RECV_BAD_TLV: Received SSTP BPDU with bad TLV on StackPort1 VLAN1.
Mar 11 09:06:00: %SPANTREE-2-RECV_BAD_TLV: Received SSTP BPDU with bad TLV on StackPort1 VLAN1.
Mar 11 09:06:04: %SPANTREE-2-UNBLOCK_CONSIST_PORT: Unblocking StackPort1 on VLAN0307. Port consistency restored.
Mar 11 09:06:32: %SPANTREE-2-RECV_BAD_TLV: Received SSTP BPDU with bad TLV on StackPort1 VLAN1.
Mar 11 09:07:02: %SPANTREE-2-RECV_BAD_TLV: Received SSTP BPDU with bad TLV on StackPort1 VLAN1.
Mar 11 09:07:03: %SPANTREE-2-RECV_PVID_ERR: Received BPDU with inconsistent peer vlan id 207 on StackPort1 VLAN307.
Mar 11 09:07:03: %SPANTREE-2-BLOCK_PVID_LOCAL: Blocking StackPort1 on VLAN0307. Inconsistent local vlan.
Mar 11 09:07:34: %SPANTREE-2-RECV_BAD_TLV: Received SSTP BPDU with bad TLV on StackPort1 VLAN1.
Mar 11 09:07:45: %SPANTREE-2-UNBLOCK_CONSIST_PORT: Unblocking StackPort1 on VLAN0307. Port consistency restored.Jim,
We have also the same problem with our 2960-X switches (access) connecting to a pair of 4500x (VSS) except our issue is with Portchannel with 2 physical links connecting the 2960xs to the 4500.
If we disconnect one of the physical links from the portchannel everything works fine, but when we connect the same physical link back all users lose connectivity and the physical link starts flapping. Here are some of the messages we see in the logs when both physical links are in the portchannel:
Mar 10 18:00:43 EST: %SPANTREE-2-RECV_PVID_ERR: Received BPDU with inconsistent peer vlan id 1 on Port-channel5 VLAN90.
Mar 10 18:00:43 EST: %SPANTREE-2-BLOCK_PVID_PEER: Blocking Port-channel5 on VLAN0001. Inconsistent peer vlan.
Mar 10 18:00:43 EST: %SPANTREE-2-BLOCK_PVID_LOCAL: Blocking Port-channel5 on VLAN0090. Inconsistent local vlan.
Mar 10 18:00:58 EST: %SPANTREE-2-UNBLOCK_CONSIST_PORT: Unblocking Port-channel5 on VLAN0001. Port consistency restored.
Mar 10 18:00:58 EST: %SPANTREE-2-UNBLOCK_CONSIST_PORT: Unblocking Port-channel5 on VLAN0090. Port consistency restored.
Mar 10 18:01:29 EST: %LINEPROTO-5-UPDOWN: Line protocol on Interface TenGigabitEthernet1/0/1, changed state to down
Mar 10 18:01:37 EST: %LINEPROTO-5-UPDOWN: Line protocol on Interface TenGigabitEthernet1/0/1, changed state to up
Mar 10 18:01:48 EST: %LINEPROTO-5-UPDOWN: Line protocol on Interface TenGigabitEthernet1/0/1, changed state to down
Mar 10 18:01:51 EST: %LINEPROTO-5-UPDOWN: Line protocol on Interface TenGigabitEthernet1/0/1, changed state to up
We have upgraded to 15.0(2a).EX5 and still have the same issue.
We have a ticket open with Cisco and have sent them all the logs and debugs and waiting to hear back from IOS developers.
HTH -
Spanning Tree Reconfiguration - If Root Port is down.
Hello All,
I have some doubt on STP reconfiguration if Root port is down ...Can any one help...?
As per my understanding, if any port is down due to any reason, the corresponding bridge shall sends a TCN to the root bridge through the root port.
Lets say if a root port is down on a bridge, and so, the topology has to be re-established. As the root port itself is down, how does the Bridge convey the TCN to the root bridge ?
Thanks,
RajaSekharHi Raja, if the root port is down, the TCN notification can't make it to the root bridge since the link is down. The affected device will rely on the last known good bpdu. When the affected device has it's designated port down, it will remove the alternate port from discard once it hits the max age table then progress through the listening, learning, forwarding, at this time the new tcn is sent through the spanning tree topology. Once the TCN reached the root bridge, the root bridge will send a configuration bpdu then the whole spanning tree topology will update.
It can take up to 52 seconds to have the topology update in the entirety depending on spanning tree mode and size of topology.
-Tom
Please rate helpful posts -
Hi all,
I am experiencing an RSTP problem. I have two swtitches connected via wireless link, the port is in trunk mode, the native vlan is vlan 1 the problem is that bpdu's are exchanged for other vlan's but not for vlan 1, when i connect a second backup wireless link it causes the loop, it seems that there are no bpdu exchanges between switches for vlan 1, also in trunk ports i see that BPDU's for vlan 1 are sent by both switches but they do not receive any BPDU's from each other. Any explanation about thiss issue ?
Thanks in advanceI would need to know some things to troubleshoot this:
1. Is VLAN 1 the native VLAN of the trunk, on both sides?
2. I presume VLAN 1 is in the allowed VLANs list on both sides of the link?
3. If the native VLAN is not 1, is the native VLAN allowed on the trunk, on both sides?
4. What model of switch is it, and what version of the software?
5. Can you do a show run int for each end of each trunk link?
6. Can you do a show int xxx trunk for each end of each trunk link?
7. Can you do a show spanning-tree vlan 1 on each side of each trunk?
Kevin Dorrell
Luxembourg -
I have a CAT4006 with 2 layer-2 uplinks to 2 CAt3750 switches respectively
CAT4006 as PLWARBITES008 connected to:
Connection 1
============
PLWARBITES008 (G1/1)connected to PLWARBITMP001 (G1/0/8)
Note: Connection down
Connection 2
============
PLWARBITES008 (G1/2)connected to PLWARBITMP002 (G1/0/8)
NOte: Connection is up
The connection 1 is down, however,
if I show cdp nei G1/1 in PLWARBITES008,
(Seems connected to itself)
I got this:
PLWARBITES008#sh cdp nei GigabitEthernet1/1 det
Device ID: PLWARBITES008
Entry address(es):
IP address: 134.1.1.1
Platform: cisco WS-C4006, Capabilities: Switch IGMP
Interface: GigabitEthernet1/1, Port ID (outgoing port): GigabitEthernet1/1
Holdtime : 145 sec
Version :
Cisco IOS Software, Catalyst 4000 L3 Switch Software (cat4000-I5S-M), Version 12.2(25)EWA1, RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
However, in PLWARBITMP001 (g1/0/80), the serial and line protocol are down. Can I know why is it like that?Hi:
That is called PVSTP , Per vlan Spanning tree protocol. It is default feature with L2 & L3 switches of Cisco. One connection is in forwarding state & one is in blocking state.
regards
Sandipani C -
Can't configure a SCXI chassis (PXI-1010) with a PXI-8176 and a PXI-6052E.
I have a PXI-1010 chassis with a PXI-8176 running Windows 2000. In the rightmost PXI slot, I have a PXI-6052E. The remaining PXI slots are either empty or have misc. modules in them. I have a SCXI-1520 in the leftmost SCXI slot.
I am trying to get MAX to recognize my SCXI chassis with the SCXI-1520. When I try to add the SCXI chassis in MAX by right-clicking "Devices and Interfaces" or "NI-DAQmx", I leave the communication mode to communicate on the PXI backplane, choose SCXI slot zero, and find that the communication device field is greyed out where I want to choose the PXI-6052E. For some reason,the wizard used to add an SCXI chassis does not see my PXI-6052E pluged in to the leftmost sl
ot. Strangely, MAX does see the PXI-6052E in the "Devices and Interfaces" tree. I verified that the 6052E is working correctly. I also verified that the pxisys.ini file is in the WINNT directory. What is the problem?I am first trying to install the SCXI chassis using the SCXI 1520 user manual. I put a PXI-6052E in the right-most PXI slot and the SCXI 1520 in a SCXI slot. On page 1-12 of the SCXI-1520 user manual, it instructs me to power up the chassis, right-click on MAX "devices and interfaces", choose the correct chassis, and click finish. The problem is, after I click finish, a window appears that forces me to choose a DAQ device. The SCXI chassis doesn't configure correctly because the wizard doesn't see the PXI-6052E.
-
NI PXI 8176 upgrade from RT 8.5.1 to LABVIEW RT 2011.
How, can I upgrade the configuration of the NI PXI-8176 from RT 8.5.1 to LabVIEW RT 2011?.
The chassis where the NI PXI-8176 connects, is the model PXI-1002
SimbaniHi,
you need a Target CD as described here:
http://digital.ni.com/public.nsf/allkb/C48FC4B99E3AFF85862574AB0074CCB5?OpenDocument
After installing LabVIEW and LabVIEW RT 2011, I think you could create a format floppy disk o USB device in MAX so as to format your controller with the newer version of LabVIEW. -
Hi all,
i read that portfast should only be enabled on access ports not on trunk ports.
when this command is used
spanning-tree portfast trunk?
under what cases we will use portfast command on trunk port ?
thanks
mahesh.... and there is one more case:
you have access switch full of users and you want to provide them redundancy for internet connection, sou you use HSRP for example and now you have switch connected to 2 or more routers with internet links
now, those links between switch and routers are also trunks and the topology is like a triangle with the switch on the tip , omitting PCs for now , at this point the only device taken into consideration is the switch - others don't use STP because routers have configured IP addresses on subinterfaces (each for one VLAN) so they break BRdomain and computers don't care about STP. In this case, you are sure that no routing loop can occur because other devices (all of them are L3) are boundary for that L2 segment and arp requests broadcasted in your LAN stay inside.
What you've just managed to make is faster trunk transition to UP state so after reload of that switch, your users can quickly use network again. -
Hi,
How to identify spanning tree loop in switched network.
I want to know all the possible ways.
Regards
skraoHi Skrao,
One thing that happens when you have a loop in a switched network is that you get a broadcast storm. Since Ethernet has not "Time To Live" field, if you have a loop in your network then the broadcasts get transmitted round the loop forever, saturating all the links.
Spanning Tree is a protocol designed to identify the loops and to cut them. There is not really any such thing as a "Spanning Tree loop", because Spanning Tree actually prevents loops. Do NOT disable it unless you are 110% sure that you have no physical loops in your network.
So, if you have a network that is looping, how do you identify where Spanning Tree is not working? It is made difficult by the fact that your network has stopped functioning correctly. The switches may be too busy to give you access to the management functions.
In most cases, the loop is due to a very recent change. Usually, creating a loop makes the network go down immediately, or exactly 90 second later. What has changed recently?
If you can access the management functions, then find out which VLAN has the traffic storm, and trace it out.
If your access switches have redundant uplinks, then disconnect them, leaving one uplink per access switch, and see if the storm stops. You should have uplinkfast running anyway, so this should not disrupt your traffic any more than it is already.
Know your network before the loop happens! In this case, prevention is really better than cure. If you can, put a broadcast limit on all your trunks. Enable BPDU guard on all your access ports.
Sniff the storming broadcasts, and look at the source MAC addresses. Use these brodcasts to identify the access switch involved.
Anyone else got any techniques they use to identify the loops?
Kevin Dorrell
Luxembourg -
Hello,
I'm using the RV220W in a small office. Now I would like to add two switches with spanning tree activated. I can see from the RV220W datasheet that it supports spanning tree. I also found a manual to configure it.
http://sbkb.cisco.com/CiscoSB/ukp.aspx?login=1&pid=2&app=search&vw=1&articleid=2296
Article ID 2296
The problem is I can't find this settings on my router which has got the newest firmware 1.0.5.8
Is it activated by default, or was this function deleted in later firmware versions?
Regards
Timo OstendarpThe 7ks as roots with the priority and peer-switch commands as you show above would be best practice. With that, you wouldn't have to make any non-default spanning-tree settings on the 5k switches.
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