Ether-Channel(Trunk) redundancy problem!!

[Tekkie123]

Hi,
I have two Wireless Ethernet Bridges which are connecting our two branch offices, with HP2848 Switch at each end.For the best bandwidth utilization I have implemented Ether-Channel Trunk configuration on HP & its working,as both links are now utilized.
Problem:
If one of the links go down,traffic doesn't shift on the remaining link, & the link goes down.Pls note,by default STP was disabled on both HP switches, which I have now enabled(in RSTP moode),but still failover is not working.Following is the configuration of trunk done at each HP2848:
"speed-duplex 100-half
no lacp
trunk 43-44 Trk20 Trunk"

What could be the problem..Kindly advice!
Regards,
Tekkie123

[Shadow13]

can you tell me what is the status of the other port on the trunk if the 1st one goes down?? is it up or down in "show interface"

[Tekkie123]

Dear Friend!!
Regarding the Ether-channel, when one link is down,,the interface at other end is 'Up'.
Now there is one more interesting thing happening. Redundancy is working!! but only for one of the links. As I have two set of Radios(different brands), one with 10Mb/s & other with 20Mb/s throughput, when I disconnect radio connected at interface 44,the port at other end stays up, & link also stays up.
But when I disconnect radio connected at interface 43, link goes down although still port at other is stays up.
Therefore, I understand that redundncy is there, but only in case one of the pair goes down & not when the other goes down.
Hope u understand!!
Regards,
Saif.

[Shadow13]

Sorry for the late reply i just saw the topic again.



You need to configure UDLD for the switch to check on the link and if it's down it will block it and use only the other one.

The issue you are facing is because tha switch are not directly connected, they are connected to the bridges, so if the port is down on the other side the switch wont detect it since the link to the bridge is up.

here comes the role of the UDLD, it send health check packets to the other end to check the status every 5 secs, and if no reply after 4 intervals the link is blocked.

To configure it please refer to the "Management and configuration guide for the 2848 switches

Regards,