cisco/hp STP issues

[paublo]

Hi, hoping someone has some suggestions.
I ran into an issue where I have a ring of 4 HP2512 and 1 HP2524 switches. These switches all connect back to a Cisco 6509.

IOS (tm) s72033_rp Software (s72033_rp-ADVIPSERVICESK9_WAN-M), Version 12.2(18)S
XF14, RELEASE SOFTWARE (fc1)

The cisco 6509 is running rapid-pvst and the HP switches are running rstp. The cisco was the root bridge and all HP’s saw the cisco as the bridge however I ran into issues where everything would work as expected for several minutes, 7 -10 min, and then parts of the network would become inaccessible all of the sudden without it ever bring up a redundant path. I also saw numerous STP topology changes etc on the HP switches while this was going on.

When I 1st brought this online I tested it by bringing down a link and STP saw the change and calculated an new path through STP. I figured this was working well but then I started having the issues mentioned above. One thing I wanted to mention this ring of HP switches is connected through wireless links using ceragon and a net-2-net t3 to Ethernet converter which which then connects to the HP switches.

Now that I have STP disabled and got rid of the redundant link, I see no errors on the HP port’s, no wireless EQ errors, and nothing on the logs indication an issue. My question is does anyone have any idea what could of happened.


Here is a snippet from one of the HP logs:

I 01/01/90 01:02:57 ports: port 8 is Blocked by LACP
I 01/01/90 01:02:58 ports: port 8 is now off-line
I 01/01/90 01:03:05 ports: port 8 is Blocked by LACP
I 01/01/90 01:03:05 ports: port 8 is Blocked by STP
I 01/01/90 01:03:06 ports: port 8 is now on-line
I 01/01/90 01:03:06 ports: port 7 is Blocked by STP
I 01/01/90 01:03:06 ports: port 7 is now on-line
I 01/01/90 01:03:08 ports: port 8 is now off-line
I 01/01/90 01:03:10 ports: port 8 is Blocked by LACP
I 01/01/90 01:03:13 ports: port 8 is Blocked by STP
I 01/01/90 01:03:15 ports: port 8 is now on-line
I 01/01/90 01:03:15 ports: port 7 is Blocked by STP
I 01/01/90 01:03:15 ports: port 7 is now on-line

THANKS!

 

[paublo]

Forgot to mention everything terminates on the cisco 6500 SVI interface on vlan105 and not the native VLAN. The HP’s are set to use vlan 1 untagged (default)

 

[Viconsul]

What do you have connected to ports 7 and 8 in the HP switch from which you posted the logs? My assumption is you have a wireless radio connected to each - is that correct?
Could you post a network diagram so that we can understand the setup? My initial thought is that your radio links are flapping/unstable causing rstp to converge the network and reconverge over and over again.

 

[paublo]

turns out there is a compatibility issue between cisco's RPSVT+ and HP's RST. solution is to run MST on all switches/cisco or like i did disable the vlan on the cisco create a routed interface, connect the HP's to it and run RST on the HP's only.

 

[burtsbees]

If HP does not support per-vlan STP, and you have PVST+ enabled on the Cisco, then you could have either forwarding loops (pvst BDPU's not making full-circle, due to the HP only recognizing STP for the entire ST topology and not for separate vlans) or just a bunch of blocked ports. PVST+ can usually mitigate this by marking a link or a few links as "state inconsistent", but that depends on the topology.

In other words, it is always best (yet not always possible) to match versions, types etc. of the STP.

/

tim@tim-laptop ~ $ sudo apt-get install windows
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Couldn't find package windows...Thank Goodness!

 

[unclerico]

yeah, your best bet is to run MST on all switches. make sure the ios you are running is a recent version otherwise you may run into cisco pre-standard MST. also, if you haven't used MST before you need to be sure that you get your VLANs created and assigned (pre-staged even, with VLANs that you don't yet use, but may in the future) to MSTIs otherwise you will feel the pain of convergence when you try to add a new VLAN to your topology.

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