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New Member

fibre uplink going up and down

hi i have a prob. i have a 2950 xl switch with fibre uplink.every 5 to 10 min time intervel the interface is going up and down.i changed the cable from, patch panel. but still the same.

our cable team tested the fibre link it is ok.

my switch is in VLAN.

int fa0/1 to 24 in vlan no 8

interface fa0/1-24

switchport access vlan8

spantree portfast

the above 3 line is for all the 24 ports.

and my uplink config is.

int fa2/4

trunking is enabled with dot1q encapsulation.and the port is in trunk mode.

i can see input errors and Crcs on my fibre link.around 300 input errors and 160 or some crcs.

once i got an error like

%sys-3 cpu HoG.

and sometimes on console its showing some messages like.

"int fa2/4 is experiencing errors".

kindly help.



New Member

Re: fibre uplink going up and down

Can u put "sh int " for the up-link port....

are there any errors on it?

are u using port channle ? and i assume all the 24 ports are cooneting to hots so u have port fast...correct if wrong...

New Member

Re: fibre uplink going up and down

Check also speed and duplex settings on the both sides. If it is AUTO change it to static (again same on both sides).

Is fiber connected direct to switches on both sides or you use fiber-to-tp convertors?

//Mikhail Galiulin

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