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VLANS - Dual LACP / RJ-45 / Mini-GBic

Occasional Visitor

VLANS - Dual LACP / RJ-45 / Mini-GBic



Our head switch consists of a stack of 2 units 3800. It serves as a gateway for all VLANs based in our organization. So the IP routing is enabled.
Currently, the links to the distribution switches are 2 links ethernet RJ-45 with LACP mode and carrying 4 VLANs. The distribution switches models are ProCurve 2810, 2510 or 2530.

We have fiber modules installed in the head switch and each distribution switch. Mini-GBIC J4858C. 2 modules per switch distribution. So I again created LACP trunk on which VLANs are configured the same as the RJ-45 LACP.

I have to turn on the fiber fonctionnality. When I activate the fiber communication (set enable), communication is via these links and MSTP blocks the RJ-45 LACP.


The problem: As soon as the fiber connectivity is ON: Only one VLAN can be reached, ie VLAN 10 (tagged). Other tagged VLANs are not reachable. It seems that the routing switch at the top does not work using this link. Yes all vlans are tagged for this LACP and the default VLAN is untagged.
I enabled the port miroring on a distribution switch (fiber module) to see if it sent pakets of a different VLAN than 10 to the switch head. Yes, I see the packets in Wireshark. But no answer. (ICMP ping request)
When I do "show LACP" I see both sides of the functional links with the ports.
If I try to see the MAC address associated with VLANs from head, I is ok. But not from the distribution switch. There is only data for the VLAN 10. I tried that for 2 different distribution switch.
As soon as I switch back to the copper communication links LACP, communication with all VLANs becomes functional.
The configuration is the same for both trunks (LACP) RJ-45 or fiber across the switch.
I have only one instance of MSTP.
IP configuration of switch distribution is enabled for the VLAN 99 and the default gateway is on the head siwtch. When the fiber is activated, it can not join this VLAN (tagged).
Thank you very much for your help. It is quite possible that small detail can make it all work!

Frequent Advisor

Re: VLANS - Dual LACP / RJ-45 / Mini-GBic

Please give us a list of each port number involved in each inter-switch link, per switch, including trunk port numbers.


Please do a "show vlan nnn" for each VLAN carried by that link.

Do this for each switch on either side of each link.


Obviously there is some configuration that is not quite right.


Personally, the first thing I would do is I would delete the non-working LACP trunks and get each physical link working individually before then trying to trunk them together.