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LACP aggregation betweeen 1800-24G and Cisco 3950E

Alan Brown
Occasional Advisor

LACP aggregation betweeen 1800-24G and Cisco 3950E


Does anyone have pointers for how to achieve this?

I thought I had it working, but the Cisco keeps complaining periodically about loops - macs in other parts of the network are being reflected out of the Procurve. When it sees this, the Cisco automatically shuts down the ports and the procurve ends up isolated from the rest of the network for about a minute - this is long enough to be noticable and users complain.

It's a bit of a pity in some ways that the 1800s don't have spanning-tree when other price-comparable switches do.
6 REPLIES
Pieter 't Hart
Honored Contributor

Re: LACP aggregation betweeen 1800-24G and Cisco 3950E

your problem probably does not lie in LACP.
an LACP trunk is seen as a single link, so it is not seen as a loop.

all switches have knowledge about spanning-tree!
if you connect two (or more) 1800's with multiple links then stp will work fine.

but there are some "dialects" in stp protocol.
your cisco most likely is configured for pvst+ (per vlan stp), where the procurve possibly uses normal stp or mstp.

if you use a single vlan on your network (or only use a single vlan on the connection to the the 1800) then you may get it to work.
switch back to stp instead of pvstp (on the whole network).

with multiple vlan's it could get more troublesome.
look into the "switchport mode trunk vlan allowed...." command on the cisco to limit the bpdu-packets sent to the 1800 only for vlan's that do occur on the 1800.

for further advice, more info about your network setup is needed.
Alan Brown
Occasional Advisor

Re: LACP aggregation betweeen 1800-24G and Cisco 3950E

> all switches have knowledge about spanning-tree!

1800s don't.

> if you connect two (or more) 1800's with multiple links then stp will work fine.

No, it doesn't.

I'm surprised. Other brands with nearly identical specs at the same price point do have STP. I assume HP removed the functionality from their version in order to prevent cannibalization of higher value switch sales, but our initial reaction is simply to switch to Cisco units.

Pieter 't Hart
Honored Contributor

Re: LACP aggregation betweeen 1800-24G and Cisco 3950E

>>>
> all switches have knowledge about spanning-tree!

1800s don't.
<<<
you may be right there!
i found refenrence in :
http://cdn.procurve.com/training/Manuals/1800-RelNotes-PA0302_PB0302-59918596.pdf
page-5
release PA.02.04/PB.02.04 Enhancenments
about BPDU-packets being recognized and passed, but I overlooked the "never released" remark about this enhancement.

but my remark about LACP still stands.
this is a single link (both ports active) and not a loop (one port blocked by stp).

so your problem needs further investigation.
please post vlan and LACP configuration, and if possible status, on the ports connecting the cisco and the procurve.
Drew Redman
Valued Contributor

Re: LACP aggregation betweeen 1800-24G and Cisco 3950E

(never released) simply means that release PA/PB.02.04 was never released individually. The changes listed under that version were still released in the next public version, however (PA/PB.02.05).

Alan, the trunk groups on the 1800 are static LACP trunks, so assuming you have the Cisco "Channel group" configured for static LACP, it should be working. In this case, I would guess that the loop exists elsewhere. Unfortunately there is not much other LACP troubleshooting that can be done on that switch.
Pieter 't Hart
Honored Contributor

Re: LACP aggregation betweeen 1800-24G and Cisco 3950E

look at : http://www.hp.com/rnd/support/faqs/1800.htm#question0

Q: Does the ProCurve Switch 1800 series support Spanning Tree Protocols?
No, the ProCurve Switch 1800 Series does not support any of the Spanning Tree Protocols (802.1s, 802.1D, or 802.1w). In addition to not supporting Spanning Tree, the switch will not pass Spanning Tree BPDUs (destination MAC = 01:80:C2:00:00:00) from upstream devices.

the remark about BPDU's should have been updated using the newer firmware.

AUS Adam
Advisor

Re: LACP aggregation betweeen 1800-24G and Cisco 3950E

Ok to bad the 1800's don't support STP. But as meantioned before a LACP trunk / Etherchannel should be seen as one link so no STP required.

I'm guessing that maybe the one of the physical links is dropping out of the LACP Trunk / Etherchannel group and this creates a loop.

If that is the case try a static trunk (i'll let you read the doco and see if its supported on your 1800)

But heres the config example
Cisco side
(config) interface port-channel 1
(config-if) exit
(config) interface fastethernet 0/1
(config-if) channel-group 1 mode ON
(config) interface fastethernet 0/2
(config-if) channel-group 1 mode ON

ProCurve side (not sure if the 1800 supports CLI or is it just web based?)
trunk 1-2 Trk1 Trunk